‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other. of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other. of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
CHIMNEYS AND VENTS
811.2.2 Chimneys.
The exhaust pipe may be connected to a chimney used for other equipment, provided that the 
operation of the engine does not adversely affect the operation of the other equipment so that it is in violation of 
the 
New York City Air Pollut
ion Control Code.
811.3 All other engine and turbine discharge opening termination requirements.
The location of the discharge 
outlet from all other engines and turbines shall comply with the termination requirements of Section 801.21, Item 2 
or Section 80
1.21, Item 3 based on the temperature of the flue gas entering the exhaust system.
811.4
Chimneys.
The exhaust system may be connected to a chimney used for other appliances, provided that the 
chimney complies with Section 811.1, Item 1 or Section 811.1, I
tem 2 and the operation of the engine does not 
adversely affect the operation of the other appliances and is in accordance with the 
New York City Air Pollution 
Control Code.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
CHIMNEYS AND VENTS
811.2.2 Chimneys.
The exhaust pipe may be connected to a chimney used for other equipment, provided that the 
operation of the engine does not adversely affect the operation of the other equipment so that it is in violation of 
the 
New York City Air Pollut
ion Control Code.
811.3 All other engine and turbine discharge opening termination requirements.
The location of the discharge 
outlet from all other engines and turbines shall comply with the termination requirements of Section 801.21, Item 2 
or Section 80
1.21, Item 3 based on the temperature of the flue gas entering the exhaust system.
811.4
Chimneys.
The exhaust system may be connected to a chimney used for other appliances, provided that the 
chimney complies with Section 811.1, Item 1 or Section 811.1, I
tem 2 and the operation of the engine does not 
adversely affect the operation of the other appliances and is in accordance with the 
New York City Air Pollution 
Control Code.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
CHIMNEYS AND VENTS
811.2.2 Chimneys.
The exhaust pipe may be connected to a chimney used for other equipment, provided that the 
operation of the engine does not adversely affect the operation of the other equipment so that it is in violation of 
the 
New York City Air Pollut
ion Control Code.
811.3 All other engine and turbine discharge opening termination requirements.
The location of the discharge 
outlet from all other engines and turbines shall comply with the termination requirements of Section 801.21, Item 2 
or Section 80
1.21, Item 3 based on the temperature of the flue gas entering the exhaust system.
811.4
Chimneys.
The exhaust system may be connected to a chimney used for other appliances, provided that the 
chimney complies with Section 811.1, Item 1 or Section 811.1, I
tem 2 and the operation of the engine does not 
adversely affect the operation of the other appliances and is in accordance with the 
New York City Air Pollution 
Control Code.
‡‡‡ Chapter 8 was amended by 
Local Law 
77 
of 2023
. This law has an effective date of June 10, 2023.
CHAPTER 8
CHIMNEYS AND VENTS
SECTION MC 801
GENERAL
801.1 Scope.   
This chapter shall govern the installation, 
maintenance, design, minimum safety requirements
, repair 
and approval of factory
-
built 
chimneys, chimney liners, vents and connectors
, and field
-
built chimneys and connect-
ors for all nongas
-
fired appliances. 
This chapter shall
also
govern the utilization of masonry chimneys. Gas
-
fired 
appliances shall be vented in accordance with the
New Yor
k City 
Fuel Gas Code.
The construction, repair, mainte-
nance and approval of masonry chimneys shall be regulated by the 
New York City Building Code.
Venting systems 
shall be designed in accordance with this chapter and comply with the requirements of the 
Ne
w York City Air Pollu-
tion Control Code
. 
801.1.1 Existing chimneys and vents.
Existing
chimneys and vents shall comply with the requirements of Section 
28
-
104.13 of the 
New York City Administrative Code
and Sections 801.1.1.1 through 801.1.1.8 of this code.
801.1.1.1 Responsibility of owner of taller building.
Whenever a building is erected, enlarged, or increased 
in height so that any portion of such building, except chimneys or vents, extends higher than the top of any 
existing chimneys or vents within 100 feet (30 480 mm), the owner of such new or altered building shall have 
the responsibility of altering such chimneys or vents to make them conform with the requirements of this 
chapter. A chimney or ve
nt that is no longer connected with a fireplace or combustion or other equipment for 
which a chimney or vent was required shall be exempt from this requirement. Such alterations shall be accom-
plished by one of the following means or a combination thereof:
1.
Carry up the existing chimneys or vents to the height required in this chapter.
2.
Offset such chimneys or vents to a distance beyond that required in this chapter from the new or altered 
building provided that the new location of the outlet of the offset chimney or vent shall otherwise comply 
with the requirements of this chapter.
Such requirements shall not dispense with or modify any additional requirements that may be applicable 
pursuant to rules of the New York City Department of Environmental Prote
ction. 
801.1.1.1.1 Chimney and vent plan. 
Applications for a new or altered building shall include a chimney and 
vent plan submitted pursuant to Section 107.18 of the 
New York City Building Code
. 
801.1.1.2 Protection of draft.
After the alteration of a chimney or vent as required by this section, it shall be 
the responsibility of the owner of the new or altered building to provide any mechanical equipment or devices 
necessary to maintain the proper draft in the equipment.
801.1.1.3 Written notification, pl
ans and required documents.
The owner of the new or altered building 
shall notify the owner of any building that may require a chimney or vent to be altered. Notification, plans 
and required documents shall comply with the requirements of Sections 801.1.1.
3.1 through 801.1.1.3.3. 
801.1.1.3.1 First notice.
Written notice in a form acceptable to the department shall be provided to the 
building owner not less than 60 days prior to a request for permit for construction on the new or altered 
building. Such noti
ce shall include a request for access to determine the need to alter the existing chimney 
or vent and a description of such work. Notice shall be sent by regular mail and certified mail, return 
receipt requested. A copy of such return receipt shall be file
d with the department.
801.1.1.3.2 Second notice. 
Written notice in a form acceptable to the department shall be provided to the 
building owner not more than 45 days following commencement of work after a permit has been issued 
for the new or altered build
ing. Such notice shall include a request for access to determine the need to 
alter the existing chimney or vent and a description of such work. Notice shall be sent by regular mail and 
CHIMNEYS AND VENTS
certified mail, return receipt requested. The second notice shall also 
be posted by a licensed process server 
at the public entrance of the building 
requiring a chimney or vent to be altered.
A copy of such return 
receipt and proof of service by the licensed process server shall be filed with the department. 
Exceptions: 
1.
A second notice shall not be required where an application to alter the affected chimney or vent 
has been filed with the department. 
2. A second notice shall not be required where access is granted and conditions are observed that 
result i
n a determination that chimney or vent alteration is not required and a revised chimney 
and vent plan is submitted to the department.
801.1.1.3.3 Plans and required documentation for alteration work. 
Where access is granted and con-
ditions are observed that
result in a determination that chimney or vent alteration is required, plans for 
such alteration work shall be provided to the owner of the existing building and a request for written 
consent to submit construction documents and perform such work shall be
made.
801.1.1.4 Approval.
The construction documents for the proposed chimney extension, alteration or reloca-
tion shall be submitted to the department pursuant to Section 28
-
104 of the 
New York City
Administrative 
Code
.
No certificate of occupancy shall b
e issued for the new building pursuant to Section 28
-
118.23 of the 
New York City Administrative Code 
until the work associated with such construction documents for the 
proposed chimney extension, alteration or relocation has been signed
-
off by the departme
nt.
Exceptions:
1.
A certificate of occupancy may be issued where access is granted and conditions are observed that 
result in a determination that chimney or vent alteration is not required and a revised chimney or 
vent plan is submitted pursuant to Sect
ion 107.18 of the 
New York City Building Code 
documenting 
such.
2.
A certificate of occupancy may be issued in accordance with Section 28
-
118.23, Exception 2 of the 
New York City Administrative Code
. 
801.1.1.5 Refusal of consent.
If consent is not gr
anted by the owner of the affected building to do the 
alteration work required by this section, such owner shall signify his or her refusal in writing to the owner 
of the new or altered building and to the commissioner; and the owner of the new or altered 
building having 
provided the notices required by Section 801.1.1.3 shall thereupon be released from any responsibility for 
the proper operation of the equipment due to loss of draft and for any health hazard or nuisance that may 
occur as a result of the ne
w or altered building. Such responsibilities shall then be assumed by the owner of 
the previously constructed building. Similarly, should such owner fail to grant consent within 45 days from 
the date of the second notice or fail to signify his or her refus
al, he or she shall then assume all responsibil-
ities as prescribed above.
‡‡‡
801.1.1.6 Procedure.
It shall be the obligation of the owner of the new or altered building to:
1.
Prepare and submit a chimney and vent plan to the department pursuant to Section 107.18 of the 
New 
York City Building Code
; 
2.
Provide required notification pursuant to Section 801.1.1.3 of this code;
3.
Provide plans pursuant to Section 801.1.1.3.3 of 
this code;
4.
Prepare and submit construction documents to the department pursuant to Section 28
-
104 of the 
New 
York City Administrative Code
for the alteration of existing chimneys or vents
which conform to the 
requirements of this chapter;
5.
Obtain pe
rmit(s) for the proposed work in accordance with Section 28
-
105 of the 
New York City 
Administrative Code
;
6.
Schedule this work so as to create a minimum of disturbance to the occupants of the affected building;
7. 
Provide such essential services as are
normally supplied by the equipment while it is out of service;
8. Where necessary, support such extended chimneys, vents and equipment from this building or to carry 
up such chimneys or vents within his or her building; 
CHIMNEYS AND VENTS
9. 
Provide for the maintenance,
repair, and/or replacement of such extensions and added equipment; 
10. Make such alterations of the same material as the original chimney or vent so as to maintain the same 
quality and appearance, except where the owner of the chimney or vent shall give 
his or her consent 
to do otherwise. All work shall be done in such fashion as to maintain the architectural aesthetics of 
the existing building. Where there is practical difficulty in complying strictly with the provisions of 
this item, the commissioner ma
y permit an equally safe alternative; 
11. Comply with the tenant protection plan requirements of Section 28
-
120 of the 
New York City Admin-
istrative Code
; and
12. Comply with inspection and sign
-
off requirements of Section 28
-
116 of the 
New York City Admin
is-
trative Code
.
801.1.1.7 Existing violations.
Any existing violations on the previously constructed equipment shall be 
corrected by the owner of the equipment before any equipment is added or alterations made at the expense 
of the owner of the new or alte
red building.
801.1.1.8 Variance.
The commissioner may grant a variance in accordance with the provisions of this code. 
801.2 General. 
Every fuel
-
burning appliance shall discharge the products of combustion to a vent, factory
-
built chim-
ney or masonry chim
ney, except for appliances vented in accordance with Section 804. The chimney or vent shall be 
designed for the type of appliance being vented.
Exception: 
Commercial cooking appliances vented by a Type I hood installed in accordance with Section 507.
801.2
.1 Design.
Chimneys and vents shall be designed and constructed so as to
provide the necessary draft and 
capacity for each appliance connected to completely exhaust the products of combustion to the outside air. The 
temperature on adjacent combustible surfaces shall not be raised above 160°F (71.1°C). Chimneys and vents shall 
be designed to resist the effects of condensation that would cause deterioration of the chimney or vent.
801.2.2 Outlets.
The outlet shall be arranged so that the flue gases are not directed so that they jeopardize people, 
overheat combustible structures, 
or enter building openings in the vicinity of the outlet.
801.2.3 Support.
Chimneys and vents shall not be supported by the equipment they serve unless such equipment 
has been specifically designed for such loads.
801.2.4 Oil
-
fired appliances. 
Oil
-
fired ap
pliances shall be vented in accordance with this code and NFPA 31.
801.2.5 Gas
-
fired appliances.
Gas
-
fired appliances shall be vented in accordance with the 
New York City Fuel 
Gas Code
.
801.3 Masonry chimneys. 
Masonry chimneys shall be constructed in accor
dance with the 
New York City
Building 
Code.
801.4 Positive flow. 
Venting systems shall be designed and constructed so as to develop a positive flow adequate to 
convey all combustion products to the outside atmosphere.
801.5 Design.   
Venting systems shall b
e designed in accordance with this chapter 
and comply with the requirements 
of the 
New York City Air Pollution Control Code
.
801.6 Minimum size of chimney or vent.   
Except as otherwise provided for in this chapter, the size of the chimney 
or vent, serving 
a single appliance, except engineered systems, shall have a minimum area equal to the area of the 
appliance connection.
801.7 Solid fuel
-
burning appliance flues.   
The cross
-
sectional area of a flue serving a solid fuel
-
burning appliance 
shall be not greate
r than three times the cross
-
sectional area of the appliance flue collar or flue outlet.
801.8 Abandoned inlet openings. 
Abandoned inlet openings in chimneys and vents shall be closed by an approved 
method
, sealed air
-
tight and permanently labeled as 
abandoned
.
801.9 Positive pressure. 
Where an appliance equipped with a forced or induced draft system creates a positive pres-
sure in the venting system, the venting system shall be designed and listed for positive pressure applications.
CHIMNEYS AND VENTS
801.10 Connection to fireplace. 
Connection of appliances to chimney flues serving fireplaces shall be in accordance 
with Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. 
A noncombustible seal shall be provided below the point of connection 
to prevent 
entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.
801.10.2 Connection to factory
-
built fireplace flue. 
An appliance shall not be connected to a flue serving a fac-
tory
-
built fireplace unl
ess the appliance is specifically listed for such installation. The connection shall be made in 
accordance with the appliance manufacturer’s instructions.
801.10.3 Connection to masonry fireplace flue. 
A connector shall extend from the appliance to the flu
e serving 
a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be provided 
with access or shall be removable for inspection and cleaning of both the connector and the flue. Listed direct 
connection devices 
shall be installed in accordance with their listing.
801.11 Multiple solid fuel
-
burning appliances prohibited. 
A solid fuel
-
burning appliance or fireplace shall not 
connect to a chimney 
passageway
venting another appliance.
801.12 Chimney entrance. 
Connect
ors shall connect to a chimney flue at a point not less than 12 inches (304.8 mm) 
above the lowest portion of the interior of the chimney flue.
801.13 Cleanouts.
Factory
-
built chimneys and vents shall be provided with a cleanout opening or access door at t
he 
base of the chimney or vent installed in accordance with the manufacturer’s instructions.
Masonry and metal chim-
neys shall be provided with a cleanout opening having a minimum height of 6 inches (152.4 mm). The upper edge of 
the opening shall be located
not less than 6 inches (152.4 mm) below the lowest chimney inlet opening. The cleanout 
shall be provided with a tight
-
fitting, noncombustible cover
of a minimum size of 8 inches by 8 inches (203.2 mm by 
203.2 mm). Cleanouts shall comply with the requireme
nts of the 
New York City Air Pollution Control Code.
Exception: 
Cleanouts shall not be required for chimney flues serving masonry fireplaces, if such flues are provided 
with access through the fireplace opening.
801.14 Connections to exhauster.
Appliance c
onnections to a chimney or vent equipped with a power exhauster shall 
be made on the inlet side of the exhauster. Joints and piping on the positive pressure side of the exhauster shall be 
listed for positive pressure applications as specified by the manufa
cturer’s instructions for the exhauster
or in accord-
ance with this code
.
801.15 Fuel
-
fired appliances. 
Masonry chimneys utilized to vent fuel
-
fired appliances shall be located, constructed 
and sized as specified in the manufacturer’s instructions for the appliances being vented. 
801.16 Flue lining. 
Masonry chimneys shall be lined. The lining material shall
be compatible with the type of appli-
ance connected, in accordance with the appliance listing and manufacturer’s instructions. Listed materials used as flue 
linings shall be installed in accordance with their listings and the manufacturer’s
instructions.
8
01.16.1 Residential and low
-
heat appliances (general). 
Flue lining systems for use with residential
-
type and 
low
-
heat
appliances shall be limited to the following:
1.
Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue l
ining shall be 
installed in accordance with the 
New York City
Building Code.
2.
Listed and labeled chimney lining systems complying with UL 1777
(new and existing chimneys) or ULC
-
S635 (existing chimneys) or ULC
-
S640 (new chimneys).
3.
Other approved mater
ials that will resist, without cracking, softening or corrosion, flue gases and condensate 
at temperatures up to 1,800
°
F (982.2
°
C).
4.
Existing firebrick chimneys may be used to vent appliances if the firebrick is acid resistant and lab tested. 
The brick a
nd mortar must be inspected in accordance with Section 1705.32 of the 
New York City Building 
Code.
801.17 Space around lining. 
The space surrounding a flue lining system or other vent installed within a masonry 
chimney shall not be used to vent any other a
ppliance. This shall not prevent the installation of a separate flue lining 
in accordance with the manufacturer’s instructions and this code.
CHIMNEYS AND VENTS
801.18 Existing chimneys and vents. 
Where an appliance is permanently disconnected from an existing chimney or 
ven
t, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the 
chimney or vent shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. 
The chimney or vent shall be resized as necessary to con
trol flue gas condensation in the interior of 
the chimney or vent and to provide the appliance or appliances served with the required draft. For the venting of 
oil
-
fired appliances to masonry chimneys, the resizing shall be in accordance with NFPA 31.
801.
18.2 Flue passageways. 
The flue gas passageway shall be free of obstructions and combustible deposits and 
shall be cleaned if previously used for venting a solid or liquid fuel
-
burning appliance or fireplace. The flue liner, 
chimney inner wall or vent inne
r wall shall be continuous and shall be free of cracks, gaps, perforations or other 
damage or deterioration which would allow the escape of combustion products, including gases, moisture and 
creosote. Where an oil
-
fired appliance is connected to an existin
g masonry chimney, such chimney flue shall be 
repaired or relined in accordance with NFPA 31.
801.18.3 Cleanout. 
Masonry chimneys shall be provided with a cleanout opening complying with Section 801.13.
801.18.4 Clearances. 
Chimneys and vents shall have ai
rspace clearance to combustibles in accordance with the 
New York City 
Building Code
and the chimney or vent manufacturer’s instructions.
Exception: 
Masonry chimneys without the required airspace clearances shall be permitted to be used if lined or 
relined 
with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 
1777
or ULC
-
S635
. The chimney clearance shall be not less than permitted by the terms of the chimney liner 
listing and the manufacturer’s instructions.
80
1.18.4.1 Fireblocking. 
Noncombustible fireblocking shall be provided in accordance with the 
New York City 
Building Code.
801.19 Multistory prohibited. 
Common venting systems for appliances located on more than one floor level shall be 
prohibited.
801.20 Reserved.
801.21 Termination requirements.
Terminations shall comply with the appliance listing and manufacturer’s instruc-
tions, and the following:
1.
Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6°C) 
shall extend at least 3 feet (914.4 m
m) above the highest construction, such as a roof ridge, parapet wall or 
penthouse within 10 feet (3048 mm) of the chimney vent or flue outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys, vents or f
lues located in an area that is more than 
10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 8
-
1, shall be 
at least as high as the highest construction in such area. For purposes of determining the required heig
ht of a 
chimney, such construction shall not include other chimneys, vents or open structural framing. 
2.
Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1000°F 
(
537.8
°C) shall extend at least 10 feet (3048 m
m) above the highest construction, such as a roof ridge, or parapet 
wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same 
building as the chimney or on another building. Any chimneys located in an area mo
re than 20 feet (6096 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction in such area. For purposes of determining the required height of the chimney, such 
construc
tion does not include other chimneys, vents or open structural framing.
3.
Chimneys serving appliances or fireplaces with outlet temperatures greater than 1000°F (
537.8
°C) shall extend 
at least 20 feet (6096 mm) above the highest construction, such as roof
ridge, parapet wall, penthouse, or other 
obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building 
as the chimney or in another building. Any chimneys located in an area that is more than 50 feet (15 24
0 mm) 
from such construction, but not more than the distance determined from Equation 8
-
1, shall be at least as high 
as the highest construction located in such area. For purposes of determining the required height of the chimney, 
such construction does no
t include other chimneys, vents, or open structural framing.
4.
Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22
.
A positive 
means shall be provided to prevent water from entering the appliance.
CHIMNEYS AND VENTS 
Exceptio
n: 
Termination caps shall be permitted on listed factory
-
built chimneys unless otherwise prohibited 
by the 
New York City Air Pollution Control Code
.
5.
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys except where such
shrouds are listed and labeled for use with the specific factory
-
built chimney system and are installed in ac-
cordance with the manufacturers’ instructions.
6.
The following formula shall be used in order to determine the distance referred to in Items 1, 2
and 3 of this 
section:
D  =  F   ×   
√
A
(Equation 8
-
1)
where:
D   = 
Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the 
construction. If a single chimney is divided into multiple 
smaller flues or chimneys, measure from the 
center of the chimney outlet that is closest to the nearest edge of the construction.
F    = 
Value determined from Table 801.21.
A   = 
Free area, in square inches, of chimney flue space outlet. If a single chimney is 
divided into multiple 
smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to 
calculate “A”.
TABLE 801.21 
“F” FACTOR FOR DETERMINING CHIMNEY DISTANCES 
TYPE OF 
FUEL
“F” FACTOR
600°F (315.6°C) 
and 
less
600°F (315.6°C) to 
1000°F (
537.8
°C)
Greater than 
1000°F (
537.8
°C)
No. 2 
Fuel Oil
2.5 
2.5 
3 
No. 4, 6 
Fuel Oil,
Solid Fuels
3 
3 
3 
801.22 Drains.
A drain shall be provided for all chimneys and gas vents to remove rain water and condensation. The 
drain shall be not less than 1 inch (25.4 mm) in diameter and shall be equipped with an appropriately
-
sized p
-
trap with 
automatic trap seal primer in accor
dance with Section 1002 of the 
New York City Plumbing Code
or a float drain trap 
installed in accordance with the manufacturer’s requirements. The drain shall be sized by the design engineer and shall 
be suitable for the chimney area. For listed chimneys and gas vents, the connection tap into the chimney shall be 
determined by the manufacturer and connected to the drain piping in accordance with the listing and installation in-
structions. On all outdoor chimneys and gas vents, the connection and drain shall 
be installed indoors as close as 
practicable to the chimney base to prevent freezing.
801.23 Draft controls. 
The installation of draft controls shall comply with Sections 801.23.1 through 801.23.5.
801.23.1 Draft control devices. 
Where a draft control device is part of the appliance or is supplied by the appliance 
manufacturer, it shall be installed in accordance with the manufacturers’ instructions. In the absence of manufac-
turers’ instructions, the device shall be attached to the flue collar of the applia
nce or as near to the appliance as 
practical.
801.
23.2 Additional devices. 
Appliances requiring a controlled chimney draft shall be permitted to be equipped 
with a listed barometric draft regulator or automatic damper installed and adjusted in accordance w
ith the manu-
facturers’ instructions. Automatic dampers shall be installed in accordance with Section 803.6.
801.23.3 Thermal safety (spill) switches. 
Thermal safety (spill) switches shall be installed on barometric draft 
regulators and all other appurtenan
ces that allow dilution air into chimneys or vents. Thermal safety (spill) switches 
shall be interlocked with all of the appliances connected to the same chimney or vent.
CHIMNEYS AND VENTS
801.23.4 
Location.
Barometric draft regulators shall be installed in the same room or
enclosure as the appliance 
in such a manner as to prevent any difference in pressure between the regulator and the combustion air supply.
801.
23.5 Positioning.
Barometric draft regulators shall be installed in the position for which they were designed 
wit
h reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed 
by any part of the appliance, adjacent construction or installation hardware.
801.24 Obstructions.
Devices or items that protrude into, impe
de or restrict the flow of vent gases shall not be in-
stalled in a vent connector, chimney, or vent.
801.25 
Outdoor chimneys and vents. 
Outdoor portions of chimneys or vents shall be provided with integral R
-
8 
insulation or be provided with an R
-
8 
insulation enclosure, where exposed to the outdoors for more than 5 feet 
(1524 mm).
SECTION 
MC 
802
VENTS
802.1 General. 
Vent systems shall be listed and labeled
or field fabricated in accordance with NFPA 211.
Type L 
vents shall be tested in accordance wit
h UL 641.
802.2 Vent application. 
The application of vents shall be in accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil 
vents
Oil
-
burning appliances listed and labeled for venting 
with Type L vents; gas 
appliances listed and labeled 
for venting with Type B vents.
802.3 Installation. 
Vent systems shall be sized, installed and terminated in accordance with the vent and appliance 
manufacturer’s instructions.
802.4 Vent termination caps.
Vent termination caps shall not be permitted and a drain installed to receive condensed 
or rain water shall be
required.
A positive means, such as offsets, shall be provided to prevent water from entering 
the appliance.
Exception: 
Termination caps shall be
permitted on listed factory
-
built chimneys unless otherwise prohibited by 
the 
New York City Air Pollution Control Code
.
802.5 Type L vent terminations. 
Type L vents shall terminate in accordance with 
Section 801.21
.
802.6 Minimum vent heights.
Vents 
shall terminate not less than 5 feet (1524 mm) in vertical height above the 
highest connected appliance flue collar.
Exceptions:
1.
Venting systems of direct vent appliances shall be installed in accordance with the appliance and the vent 
manufacturer’s in
structions.
2.
Appliances listed for outdoor installations incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions.
802.7 Support of vents.
All portions of vents shall be installed in ac
cordance with the manufacturer’s instructions 
and 
shall be adequately supported for the design and weight of the materials employed.
802.8 Insulation shield. 
Where vents pass through insulated assemblies, an insulation shield constructed of not less 
than N
o. 26 gage sheet metal shall be installed to provide clearance between the vent and the insulation material. The 
CHIMNEYS AND VENTS
clearance shall be not less than the clearance to combustibles specified by the vent manufacturer’s instructions. Where 
vents pass through atti
c space, the shield shall terminate not less than 2 inches (50.8 mm) above the insulation materials 
and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall 
be installed in accordance with the
manufacturer’s instructions.
802.9 Door swing. 
Appliance and equipment vent terminals shall be located such that doors cannot swing within 12 
inches (304.8 mm) horizontally of the vent terminals. Doorstops or closers shall not be installed to obtain this 
clear-
ance.
SECTION 
MC 
803
CONNECTORS
803.1 Connectors required. 
Connectors shall be used to connect appliances to the vertical chimney or vent, except 
where the chimney or vent is attached directly to the appliance.
803.2 Location. 
Connectors shall be loca
ted entirely within the room in which the connecting appliance is located, 
except as provided for in Section 803.10.4. Where passing through an unheated space, a connector shall not be con-
structed of single
-
wall pipe.
803.3 Size. 
The connector shall not be
smaller than the size of the flue collar supplied by the manufacturer of the 
appliance. Where the appliance has more than one flue outlet, and in the absence of the manufacturer’s specific in-
structions, the connector area shall be not less than the combin
ed area of the flue outlets for which it acts as a common 
connector.
803.4 Branch connections. 
Branch connections to the vent connector shall be made in accordance with the vent 
manufacturer’s instructions.
803.5 Manual dampers. 
Manual dampers shall not be
installed in connectors except in chimney connectors serving 
solid fuel
-
burning appliances.
803.6 Automatic dampers. 
Automatically operated dampers shall be equipped with safety controls and shall be of a 
listed type. Such safety controls shall be capable
of demonstrating operation of the damper and appropriate draft before 
appliance operation. The automatically operated dampers shall be installed in accordance with the manufacturer’s 
instructions. An automatic vent damper device shall not be installed on 
an existing appliance unless the appliance is 
listed and labeled and the device is installed in accordance with the terms of its listing. The name of the installer and 
date of installation shall be marked on a label affixed to the damper device.
803.7 Connectors serving two or more appliances. 
Where two or more connectors enter a common vent or chimney, 
the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible 
material.
803.8 Vent connect
or construction.
A vent connector for a nonresidential, low
-
heat appliance
shall be 
a factory
-
built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for 
the 
appropriate 
galvanized 
pipe as specified in Table 803.8. Factory
-
built chimney sections shall be joined together in accordance 
with the chimney
manufacturer’s instructions.
TABLE 803.8
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT 
CONNECTORS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019 (No. 28 gage)
6 to less than 10
0.023 (No. 26 gage)
10 
to 12 inclusive
0.029 (No.24 gage)
14 to 16 inclusive
0.034 (No. 22 gage)
Over 16
0.056 (No. 16 gage)
CHIMNEYS AND VENTS
For SI: 1 inch = 25.4 mm.
803.9 Chimney connector construction. 
Chimney connectors for low
-
heat appliances shall be of sheet steel pipe 
having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors 
for medium
-
heat appliances and high
-
heat appliances shall be of sheet steel not less than the thickness specified in 
Table 803.9(2).
TABL
E 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR LOW
-
HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 gage)
Larger than 5 and up to 10
0.028 (No. 24 gage)
Larger than 10 and 
up to 
16
0.034 (No. 22 gage)
Larger than 16
0.064 (No. 16 gage)
For SI: 1 inch = 25.4 mm.
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR MEDIUM
-
AND HIGH
-
HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT 
ROUND DIAMETER
(inches)
MINIMUM 
THICKNESS
(inches)
0
–
154
0
–
14
0.0575 (No. 16 gage)
155
–
201
15
–
16
0.075 (No. 14 gage)
202
–
254
17
–
18
0.0994 (No. 12 gage)
Greater than 254
Greater than 18
0.1292 (No. 10 gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm
2
.
803.10 Installation. 
Connectors shall be installed in accordance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints.
Connectors shall be supported in an approved manner, and overlapping joints shall 
be tight
-
fitting and fastened with she
et metal screws, rivets, welds or other approved means.
803.10.2 Length.
The maximum horizontal length of a single
-
wall connector shall 
not affect
the 
capability
of the 
system to produce adequate draft
.
803.10.3 Connection.
The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A 
connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are 
installed to facilitate removal of the connector from 
the masonry chimney, the thimble shall be permanently ce-
mented in place with high
-
temperature cement.
‡‡‡
803.10.4 Connector pass
-
through.
Chimney connectors shall not pass through any floor or ceiling, nor 
through a fire
-
resistance
-
rated wall assembly. Chimney connectors shall not pass through walls or partitions con-
structed of combustible material to reach a chimney or vent, except where s
uch chimney connector complies with 
Section 803.10.4.1 or 803.10.4.2.
‡‡‡
803.10.4.1 Manufactured insulated chimney connectors.
Manufactured insulated chimney connectors 
that pass through walls or partitions of combustible construction must comply with the 
following:
CHIMNEYS AND VENTS
1.
The connector is labeled for wall pass
-
through and is installed in accordance with the manufacturer’s 
instructions
; or
2.
The connector is put through a device labeled for wall pass
-
through
; or
3.
The connector has a diameter not larger than 
10 inches (254 mm) and is installed in accordance with one 
of the methods in Table 803.10.4. Concealed metal parts of the pass
-
through system in contact with flue 
gases shall be of stainless steel or equivalent material that resists corrosion, softening or
cracking up to 
1,800
°
F (982
°
C).
803.10.4.2 Field
-
applied insulation for chimney connectors.
Chimney connectors of appliances with flue gas 
temperatures less than 500
°
F (260
°
C) that pass through walls or partitions of combustible construction shall be 
insu
lated with a field
-
applied flexible wrap assembly tested in accordance with either ASTM E2816 or ASTM 
E2336. The connector shall comply with all of the following:
1.
The insulated vent connectors pass
-
through assemblies and through penetration assemblies s
hall be tested 
for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to 
or exceed the fire
-
resistance rating of the mechanical/boiler room. 
2.
Bracing and supports shall be of noncombustible material securely
attached to the structure and designed 
to carry gravity and seismic loads within the stress limitations of Chapter 16 of the 
New York City
Building 
Code
. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls. 
3.
Insulat
ed vent connector pass
-
through assemblies shall not pass through ceilings or floors.
4.
Insulated vent connector pass
-
through assemblies shall not run through occupied spaces, corridors, sleep-
ing rooms and spaces with hazardous materials.
5.
Insulated vent
connector pass
-
through assemblies material shall meet the requirements for minimum 
chimney connector thicknesses for medium and high
-
heat appliances in accordance with Table 803.9(2).
6.
Insulated vent connector pass
-
through assemblies fittings shall be w
elded or shall be factory fabricated 
UL listed construction suitable for external flexible wrap insulation.
7.
The draft calculations shall account for the insulating value of the field
-
applied flexible wrap insulation.
‡‡‡
TABLE 803.10.4
CHIMNEY 
CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR HEATING 
APPLIANCES
a, b, c, d
System A 
(12
-
inch 
clearance)
A 3.5
-
inch
-
thick brick wall shall be framed into the 
combustible wall. 
A
0.625
-
inch
-
thick fire
-
clay liner 
(ASTM C 315 or equivalent)
e
shall be firmly cemented 
in the center of the brick wall maintaining a 12
-
inch 
clearance to combustibles. The clay liner s
hall run from 
the outer surface of the bricks to the inner surface of the 
chimney liner.
System B 
(9
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) the same inside diameter as the 
connector shall be utilized. 
Sheet steel supports cut to 
maintain a 9
-
inch clearance to combustibles shall be 
fastened to the wall surface and to the chimney 
section
. 
Fasteners shall not penetrate the chimney flue liner. The 
chimney length shall be flush with the masonry chimney 
liner
and sealed to the masonry with water
-
insoluble 
refractory cement. Chimney 
manufacturers’ 
parts shall 
be utilized to securely fasten the chimney connector to 
the chimney section.
CHIMNEYS AND VENTS
System C 
(6
-
inch clear-
ance)
A 
sheet metal (minimum No. 24 gage) 
ventilated 
thimble having a minimum thickness of 0.0236 inch (No. 
24 gage) having two 1
-
inch air channels shall be 
installed. Steel supports shall be cut to maintain a 6
-
inch 
clearance
with a sheet steel chimney connector
between 
the thimble and combustibles. The chimney connector 
and steel supports shall have a minimum thickness of 
0.0236 inch (No. 24 gage). One side of the support shall 
be fastened to the wall on all sides. Glass
-
fiber insulation 
shall fill the 6
-
inch spa
ce between the thimble and the 
supports.
System D 
(2
-
inch clear-
ance)
A labeled solid
-
insulated factory
-
built chimney section 
(1
-
inch insulation) with a diameter 2 inches larger than 
the chimney connector shall be installed with a steel 
chimney connector 
having a minimum thickness of
0.0236 inch (
No. 
24 gage). Sheet steel supports shall be
positioned to maintain a 2
-
inch clearance to 
combustibles 
and to hold the chimney connector to 
ensure that a 1
-
inch airspace surrounds the chimney 
connector through the 
chimney section. The steel support 
shall be fastened to the wall on all sides and the chimney 
section
shall be fastened to the supports. Fasteners shall 
not penetrate the liner of the chimney section.
For SI: 1 inch = 25.4 mm, 1.0 Btu 
×
in/ft
2 
• 
h 
• 
°
F = 0.144 W/m
2 
• 
K.
a. Insulation material that is part of the wall pass
-
through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu × in/ft
2
• h • 
°
F or less.
b. All 
clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be 
non
-
combustible
.
d. Connectors for all systems except System B shall extend through the wall pass
-
through system to the inner face of the flue li
ner.
e. ASTM C 315.
803.10.5 Pitch. 
Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one
-
fourth 
unit vertical in 12 units horizontal (2
-
percent slope).
803.10.6 Clearances. 
Connectors shall have a minimum clearance to c
ombustibles in accordance with Table 
803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance 
specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combus
tibles for 
connectors shall be reduced only in accordance with Section 308
or via the use of a listed chimney or vent con-
nector system
.
CHIMNEYS AND VENTS
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE 
(inches)
Domestic
-
type appliances
Chimney and vent connectors
Electric and oil incinerators
18
Oil and solid fuel
-
burning appliances
18
Oil appliances labeled for venting with Type L vents
9
Commercial, industrial
-
type appliances
Low
-
heat 
appliances
Chimney connectors
Oil and solid fuel boilers, 
furnaces 
and water 
heaters
18
Oil unit heaters
18
Other low
-
heat industrial appliances
18
Medium
-
heat appliances
Chimney connectors
All oil and solid fuel
-
burning appliances
36
High
-
heat appliances
In accordance with 
NFPA 
211
Masonry or metal connectors
All oil and solid fuel
-
burning appliances
For SI: 1 inch = 25.4 mm.
SECTION 
MC 
804
DIRECT
-
VENT, INTEGRAL VENT AND MECHANICAL DRAFT SYSTEMS
804.1 Direct
-
vent terminations. 
Vent terminals for direct
-
vent appliances shall be installed in accordance with the 
manufacturer’s 
instructions. In addition, direct vent terminations shall comply with the following requirements:
1.
Where located adjacent t
o walkways, the termination shall be not less than 7 feet (
2133.6
mm) above the level 
of the walkway.
2.
Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the 
subject direct vent appliance, loc
ated within 10 feet (3048 mm).
3.
The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 
foot (304.8 mm) above any door, window or gravity air inlet into the building.
4.
The vent termination point shal
l not be located closer than 3 feet (914.4 mm) to an interior corner formed by 
two walls perpendicular to each other.
CHIMNEYS AND VENTS
5.
The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas 
or electric metering, re
gulating, venting relief equipment or other building opening.
6.
The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent termination 
shall be 350,000 Btu/h 
(102.6 kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwi
se approved by the commissioner.
9.
The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent 
buildings. The termination shall be installed in accordance with the vent manufacturer’s instructions. 
804.2 Appli
ances with integral vents.
Appliances incorporating integral venting means shall be installed in accord-
ance with their listings and the manufacturer’s instructions. In addition, integral vent terminals shall comply with the 
following requirements:
1.
Where
located adjacent to walkways, the vent terminal shall be not less than 7 feet (2133.6 mm) above the 
level of the walkway.
2.
The vent terminal shall be at least 3 feet (914.4
mm) above any forced air inlet, other than the forced air inlet 
for the subject integral vent appliance, located within 10 feet (3048 mm).
3.
The vent terminal shall be at least 4 feet (1219.2
mm) below, 4 feet (
1219.2
mm) horizontally from or 1 foot 
(
304.8
mm) above any door, window or gravity air inlet into the building.
4.
The vent terminal shall not be located closer than 3 feet (914.4
mm) to an interior corner formed by two walls 
perpendicular to each other.
5.
The
vent terminal shall not be mounted directly above or within 3 feet (914.4
mm) horizontally from any gas 
or electric metering, regulating, venting relief equipment or other building opening.
6.
The bottom of the vent terminal shall be located at least 36 i
nches (914.4 mm) above finished grade.
7.
The maximum heat input of an appliance served by single horizontal vent terminal shall be 350,000 Btu/h 
(102.6 
kW), unless otherwise approved by the commissioner.
8.
The maximum heat input of all appliances served 
by horizontal vent terminals located within a 10 foot (3048 
mm) radius shall be 350,000 Btu/h (102.6 
kW), unless otherwise approved by the commissioner.
9.
The vent terminal shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacen
t build-
ings. The termination shall be installed in accordance with the vent manufacturer’s instructions.
804.2.1 Reserved.
804.3 Mechanical draft systems.
Mechanical draft systems of either forced or induced draft design shall be listed 
and labeled in acc
ordance with UL 378 and shall comply with Sections 804.3.1 through 804.3.8.
804.3.1 Forced draft systems. 
Forced draft systems and all portions of induced draft systems under positive pres-
sure during operation shall be designed and installed so as to be ga
s tight to prevent leakage of combustion products 
into a building.
804.3.2 Automatic shutoff. 
Power exhausters serving automatically fired appliances shall be electrically connected 
to each appliance to prevent operation of the appliance when the power exh
auster is not in operation.
804.3.3 Termination. 
The termination of chimneys or vents equipped with power exhausters shall be located not 
less than 10 feet (3048 mm) from the lot line or from adjacent buildings, unless otherwise approved by the com-
missione
r. The exhaust shall be directed vertically away from the building.
804.3.4 Horizontal terminations. 
Horizontal terminations and discharges, including any horizontal direct vent 
terminations subject to Section 804.1 and horizontal integral vent terminals s
ubject to Section 804.2, shall not be 
permitted, unless otherwise authorized by the commissioner.
804.3.5 Vertical terminations. 
Vertical terminations and discharges shall comply with Section 801.21.
804.3.6 Exhauster connections. 
An appliance vented by na
tural draft shall not be connected into a vent, chimney 
or vent connector on the discharge side of a mechanical flue or power exhauster.
CHIMNEYS AND VENTS
804.3.7 Exhauster sizing. 
Mechanical flue or power exhausters and the chimney or vent system served shall be 
sized and 
installed in accordance with the manufacturer’s instructions.
804.3.8 Mechanical draft systems for manually fired appliances and fireplaces. 
A mechanical draft system 
shall be permitted to be used with manually fired appliances and fireplaces where such sy
stem complies with all of 
the following requirements:
1.
The mechanical draft device shall be listed and labeled in accordance with UL 378, and shall be installed in 
accordance with the manufacturer’s instructions.
2.
A device shall be installed in the roo
m with the appliance or fireplace that produces visible and audible 
warning upon failure of the mechanical draft device or loss of electrical power, at any time that the mechan-
ical draft device is turned on. This device shall be equipped with a battery bac
kup if it receives power from 
the building wiring.
3.
A smoke detector or alarm, and a carbon monoxide detector or alarm, shall be installed in the room with the 
appliance or fireplace. This device shall be equipped with a battery backup if it receives pow
er from the 
building wiring.
SECTION 
MC 
805
FACTORY
-
BUILT CHIMNEYS
805.1 Listing. 
Factory
-
built chimneys shall be listed and labeled and shall be installed and terminated in accordance 
with 
this code and 
the manufacturer’s instructions.
805.2 Solid fuel
-
bu
rning appliances. 
Factory
-
built chimneys installed in dwelling units with solid fuel
-
burning ap-
pliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT” and “Residential 
Type and Building Heating Appliance Chimney.”
Exceptions:
1.
Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 
and shall be marked “Residential Type and Building Heating Appliance Chimney.”
2.
Chimneys for use with open combustion chamber appliances 
installed in buildings other than dwelling units 
shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” 
or “Residential Type and Building Heating Appliance Chimney.”
805.3 Factory
-
built chimney offsets. 
Where 
a factory
-
built chimney serving a solid fuel
-
burning appliance or fire-
place incorporates offsets, no part of the chimney shall be at an angle of more than 30 degrees (0.52 rad) from vertical 
at any point in the assembly and the chimney assembly shall not i
nclude more than four elbows.
Exception: 
Factory
-
built chimneys listed to UL103 Type HT serving a solid fuel
-
burning appliance or fireplace 
may offset at angles greater than 30 degrees from vertical if listed for such angles and installed in 
accordance with 
manufacturer’s instructions. Cleanouts shall be installed in accordance with Section 801.13.
805.4 Support. 
Where factory
-
built chimneys are supported by structural members, such as joists and rafters, such 
members shall be designed to supp
ort the additional load.
805.5 Medium
-
heat appliances. 
Factory
-
built chimneys for medium
-
heat appliances producing flue gases having a 
temperature above 1,000
°
F (
537.8°
C
),
measured at the entrance to the chimney shall comply with UL 959.
805.6 Decorative s
hrouds. 
Decorative shrouds shall not be installed at the termination of factory
-
built chimneys 
except where such shrouds are listed and labeled for use with the specific factory
-
built chimney system and are in-
stalled in accordance with Section 304.1.
805.7
Factory
-
built fireplaces.
Chimneys for use with factory
-
built fireplaces shall comply with the requirements of 
UL 127.
CHIMNEYS AND VENTS
SECTION 
MC 
806
METAL CHIMNEYS
806.1 General. 
Metal chimneys shall be constructed and installed in accordance with NFPA 211.
806.2 Exteri
or metal chimneys.
Exterior metal chimneys shall be stainless steel.
SECTION MC 807
CHANGES IN APPLIANCE FUELS
807.1 Changes in appliance fuels.
Conversion of appliances from solid or liquid fuel to, or the addition of, natural 
gas shall be installed per t
he 
New York City Fuel Gas Code.
Conversion from natural gas to, or the addition of, #2 
fuel oil for a heating appliance shall be made only if:
1.
The chimney design meets the requirements of this chapter for the conversion fuel, and the chimney is test run
and smoke tested in accordance with Section 810.
2.
The chimney is sized to provide adequate draft and vent the combustion products for the new fuel. 
3.
The chimney is thoroughly cleaned prior to the conversion to remove collected flue deposits.
SECTION 
MC 808
REDUCTION OF FLUE SIZE
808.1 Reduction of flue size.
Conversion from one fuel to another or the use of an existing chimney to service a 
fireplace or wood
-
burning appliance may require a flue size change for proper operation. This may be done if 
the 
redesigned flue meets the criteria for the fuel and chimney type to be used as set forth in this chapter.
SECTION MC 809
CHIMNEY SUPPORTED FROM EQUIPMENT
809.1 Chimney support.
Chimneys shall not be supported by the equipment they serve, unless such eq
uipment has 
been specifically designed for such loads.
SECTION MC 810
TEST RUN AND SMOKE TEST
‡‡‡
810.1 Test run.
All new and altered chimneys, and chimneys to which a new appliance has been connected, 
shall be test run under operating conditions to demonst
rate fire safety and the complete exhausting of smoke and the 
products of combustion to the outer air. The test run shall be conducted by a registered design professional or special 
inspector responsible for the test, and the results of such test run shall
be certified as correct by such professional or 
special inspector and submitted in writing to the department. Refer to Section 1705.32 of the 
New York City Building 
Code
for additional requirements.
Exception:
A test run in accordance with this section may be conducted and certified to the department by the 
permit
-
holder when the work is performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. The test ru
n shall not require a registered design professional or special in-
spector.
‡‡‡
810.2 Requirement of a smoke test.
A smoke test shall be made as outlined in Section 810.3. Any faults or 
leaks found shall be corrected. Such smoke test shall be witnessed by a 
representative of the commissioner. In lieu 
thereof, the commissioner may accept the test report of a registered design professional or special inspector respon-
sible for the test that shall be submitted in writing to the department.
Exception:
A smoke test
may be performed by or under the supervision of a permit
-
holder when the work is 
performed as part of a limited alteration application, as defined in Section 28
-
101.5 of the Administrative Code. 
CHIMNEYS AND VENTS
Such test shall not be required to be witnessed by the depar
tment, registered design professional or special 
inspector.   
810.3 Smoke test.
To determine the tightness of chimney construction
, a smoke test shall be made in accordance 
with the following conditions and requirements:
1.
The equipment, materials, power
and labor necessary for such test shall be furnished by, and at the expense of, 
the owner or holder of the work permit.
2.
If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the 
requirements of t
his chapter, and the test shall be repeated until the results are satisfactory.
3.
The chimney shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke 
bombs, or other equivalent method. As the smoke appears at the st
ack opening on the roof, such opening shall 
be tightly closed and a pressure equivalent to 
1
/
2
-
inch (13 mm) column of water measured at the base of the 
stack, shall be applied. The test shall be applied for a length of time sufficient to permit the inspect
ion of the 
chimney.
4.
Refer to Section 170
5
.32
‡
of the 
New York City Building Code
for requirements for existing and new negative 
pressure chimneys and vents.
SECTION MC 811
EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES AND TURBINES
811.1 Exhaust 
system construction.
The exhaust system from internal combustion engines shall be constructed in 
accordance with NFPA 211, NFPA 37, and based on the temperature of the flue gas entering the exhaust system, and 
in accordance with the following:
1.
The exhau
st system, if factory built, shall be installed in accordance with its listing and manufacturer’s instruc-
tions.
1.1.
Exhaust systems with flue gas temperatures greater than 300°F (148.9°C) shall be listed to UL 103 or UL 
2561 and be rated for a minimum of 
60 
inch w.c.
(14 934.3 Pa).
1.2.
Exhaust systems with flue gas temperatures not more than 300°F (148.9°C) and that are capable of causing 
excessive condensate production in the exhaust system shall be listed to UL 103 or UL 2561 and UL 1738 
and be rated fo
r a pressure suitable for the operating conditions.
2.
The exhaust system, if field fabricated, shall be constructed of at least 
3
/
16
-
inch (4.8 mm) steel, or of other equiv-
alent metal of similar strength and resistance to the temperature and corrosive acti
on of the exhaust gases. No 
lining shall be required.
3.
Where the exhaust system runs inside a building, it shall be insulated adequately for the equipment operating 
temperature, so that the surface temperature shall be not more than 200°F (93.3°C).
4.
Wh
ere the exhaust system runs inside a building outside of the room containing the equipment, it shall be en-
closed in fire
-
rated construction with a fire rating equal to the fire rating of the construction of the room.
5.
All joints shall be constructed so a
s to be gas tight under all operating conditions and tested in accordance with 
Section 810.
811.2 Emergency and standby generator discharge opening termination requirements.
The location of discharge 
outlets for emergency and standby internal combustion en
gines shall comply with the requirements of NFPA 37 so 
that the flue gases are not directed to jeopardize the health or safety of people, overheat combustible structures, nor 
enter building openings in the vicinity of the outlet, nor shall the location of 
such openings cause the condensate 
leaving the outlet to come into contact with people.
811.2.1 Interference.
No discharge opening shall be located and constructed so as to
interfere with the proper 
functioning of other openings in the same building or adjoining buildings, to interfere unreasonably with the 
occupants of the same building or adjoining buildings, or with the general public, or to create a fire or health 
hazard
.
CHIMNEYS AND VENTS
811.2.2 Chimneys.
The exhaust pipe may be connected to a chimney used for other equipment, provided that the 
operation of the engine does not adversely affect the operation of the other equipment so that it is in violation of 
the 
New York City Air Pollut
ion Control Code.
811.3 All other engine and turbine discharge opening termination requirements.
The location of the discharge 
outlet from all other engines and turbines shall comply with the termination requirements of Section 801.21, Item 2 
or Section 80
1.21, Item 3 based on the temperature of the flue gas entering the exhaust system.
811.4
Chimneys.
The exhaust system may be connected to a chimney used for other appliances, provided that the 
chimney complies with Section 811.1, Item 1 or Section 811.1, I
tem 2 and the operation of the engine does not 
adversely affect the operation of the other appliances and is in accordance with the 
New York City Air Pollution 
Control Code.