Update app.py

app.py

@@ -2,60 +2,59 @@ import gradio as gr
 import matplotlib.pyplot as plt
 
 def cmda_redevelopment_final_model(
-    uds, num_owners, guideline_value, market_rate, construction_cost
+    uds, num_owners, total_fsi, guideline_value, market_rate, construction_cost
 ):
-    # Step 1: Fixed FSI logic
-    normal_fsi = 2.0
-    premium_fsi = 0.8
-    total_fsi = normal_fsi + premium_fsi
+    # Constants
+    owner_fsi = 2.0
+    premium_fsi = total_fsi - owner_fsi
 
-    # Step 2: Area calculations
-    owner_total_area = normal_fsi * uds
+    # Step 1: Area calculations
+    owner_total_area = owner_fsi * uds
     builder_area = premium_fsi * uds
     total_built_up_area = total_fsi * uds
 
-    # Step 3: Premium FSI Charges
-    premium_fsi_charge = 0.4 * guideline_value * builder_area
+    # Step 2: Premium FSI Charges (new formula)
+    premium_fsi_charge = 0.4 * guideline_value * uds * premium_fsi
 
-    # Step 4: Construction cost for entire built-up area (owner + builder)
+    # Step 3: Construction cost for entire built-up area
     total_construction_cost = total_built_up_area * construction_cost
 
-    # Step 5: Builder Revenue (sale of builder share at market rate)
+    # Step 4: Builder Revenue (saleable area = premium portion only)
     builder_sale_value = builder_area * market_rate
 
-    # Step 6: Builder Profit
+    # Step 5: Builder Profit
     builder_profit = builder_sale_value - total_construction_cost - premium_fsi_charge
 
-    # Step 7: Owner Share Calculations
+    # Step 6: Owner Share Calculations
     uds_per_owner = uds / num_owners
     owner_area_per_owner = owner_total_area / num_owners
 
-    # Step 8: Chart
+    # Step 7: Chart
     fig, ax = plt.subplots(figsize=(6, 4))
-    labels = ['Owner Area (2.0x UDS)', 'Builder Area (0.8x UDS)', 'Total Area']
+    labels = ['Owner Area (2.0x UDS)', f'Builder Area ({premium_fsi:.1f}x UDS)', 'Total Area']
     values = [owner_total_area, builder_area, total_built_up_area]
     ax.bar(labels, values, edgecolor='black')
     ax.set_ylabel("Area (sq.ft)")
     ax.set_title("Redevelopment Share Breakdown")
     plt.tight_layout()
 
-    # Step 9: Output
+    # Step 8: Output
     result = {
         "Total UDS": f"{uds:.2f} sq.ft",
-        "Total Built-up Area (2.8 FSI)": f"{total_built_up_area:.2f} sq.ft",
-        "Owner Entitlement Area (2.0 x UDS)": f"{owner_total_area:.2f} sq.ft",
-        "Builder Saleable Area (0.8 x UDS)": f"{builder_area:.2f} sq.ft",
+        "Total Built-up Area (FSI × UDS)": f"{total_built_up_area:.2f} sq.ft",
+        "Owner Entitlement Area (2.0 × UDS)": f"{owner_total_area:.2f} sq.ft",
+        f"Builder Saleable Area ({premium_fsi:.1f} × UDS)": f"{builder_area:.2f} sq.ft",
 
         "--- Builder Financials ---": "",
-        "Premium FSI Charges (0.4 × guideline × area)": f"₹ {premium_fsi_charge:,.2f}",
-        "Total Construction Cost (entire 2.8x)": f"₹ {total_construction_cost:,.2f}",
+        "Premium FSI Charges (0.4 × guideline × UDS × extra FSI)": f"₹ {premium_fsi_charge:,.2f}",
+        "Total Construction Cost (entire built-up area)": f"₹ {total_construction_cost:,.2f}",
         "Builder Revenue (@ market rate)": f"₹ {builder_sale_value:,.2f}",
         "Estimated Builder Profit": f"₹ {builder_profit:,.2f}",
 
         "--- Owner Breakdown ---": "",
         "Number of Owners": num_owners,
         "UDS per Owner": f"{uds_per_owner:.2f} sq.ft",
-        "New Flat per Owner (2x UDS)": f"{owner_area_per_owner:.2f} sq.ft"
+        "New Flat per Owner (2.0 × UDS)": f"{owner_area_per_owner:.2f} sq.ft"
     }
 
     return result, fig
@@ -64,8 +63,9 @@ def cmda_redevelopment_final_model(
 inputs = [
     gr.Number(label="Total UDS (in sq.ft)", value=450),
     gr.Number(label="Number of Owners", value=4),
+    gr.Number(label="Total FSI (e.g., 2.8)", value=2.8, minimum=2.0, maximum=3.5, step=0.1),
     gr.Number(label="Guideline Value (₹/sq.ft)", value=5000),
-    gr.Number(label="Market Rate (₹/sq.ft)", value=9500),
+    gr.Number(label="Market Rate (₹/sq.ft for builder sale)", value=9500),
     gr.Number(label="Construction Cost (₹/sq.ft)", value=3500),
 ]
 
@@ -79,10 +79,10 @@ app = gr.Interface(
     fn=cmda_redevelopment_final_model,
     inputs=inputs,
     outputs=outputs,
-    title="CMDA Redevelopment Calculator - Owner-Builder Model (Fixed FSI)",
+    title="CMDA Redevelopment Calculator (Fixed Owner FSI Model)",
     description=(
-        "This calculator assumes owners are returned flats at 2x their UDS (normal FSI), and builder gets the premium FSI portion (0.8x UDS) "
-        "to sell. Builder pays full construction cost for entire 2.8x area and premium FSI charges."
+        "This calculator assumes flat owners receive 2.0× their UDS as new flats. Builder retains only the premium FSI portion "
+        "and pays for full construction and premium FSI charges. Enter realistic values to assess feasibility."
     )
 )