README.md

---
license: cc-by-4.0
task_categories:
  - question-answering
language:
  - en
tags:
  - bim
  - ifc
  - building-information-modeling
  - benchmark
  - construction
size_categories:
  - 1K<n<10K
---

# IFC-Bench

![Dataset Version](https://img.shields.io/badge/version-v2.0-blue)
![License](https://img.shields.io/badge/license-CC%20BY%204.0-green)
![QA Pairs](https://img.shields.io/badge/QA%20pairs-1027-orange)

A benchmark dataset for evaluating BIM (Building Information Modeling) comprehension and reasoning capabilities in AI systems. Provides curated IFC models with question-answer pairs across 4 complexity categories for testing BIM-related AI implementations.

**Dataset snapshot:**

| | question | ground_truth | ifc_model | project | category |
|---|----------|--------------|-----------|---------|----------|
| 0 | What modelling program and IFC standard were used to create this model? | The model was created using... | arc | 4351 | 1 |
| 1 | What are the estimated capacities for each waiting area in the building? | The information is not directly available... | arc | dental_clinic | 4 |
| 2 | What are the slab types in the building, their quantities, and available thicknesses? | The building contains the following slab types... | arc | fantasy_residential_building_1 | 2 |
| 3 | What are all the residential units on level 8, with their approximate gross areas? | Level 8 residential units... | arc | sixty5 | 3 |

## Table of Contents

- [Features](#features)
- [Dataset Structure](#dataset-structure)
- [Models Overview](#models-overview)
- [Question Taxonomy](#question-taxonomy)
- [Getting Started](#getting-started)
- [Dataset Integrity](#dataset-integrity)
- [Contributing](#contributing)
- [License](#license)
- [Citation](#citation)
- [Acknowledgments](#acknowledgments)

## Features

- **21 BIM projects** with 37 IFC models across architectural, structural, MEP, and specialty disciplines
- **1,027 question-answer pairs** covering diverse BIM information retrieval tasks
- **4 question categories** based on data retrieval complexity (direct retrieval, computational aggregation, geometric/spatial computation, incomplete information)
- **Rich contextual data**: original IFC files, model cards, license documentation
- **Machine-readable format**: CSV dataset with clear column structure
- **Versioned**: V2 dataset with V1 preserved for backwards compatibility

## Dataset Structure

```
ifc-bench/
├── projects/
│   ├── 4351/
│   ├── ac20/
│   ├── city_house_munich/
│   ├── dental_clinic/
│   ├── digital_hub/
│   ├── duplex/
│   ├── ettenheim_gis/
│   ├── fantasy_hotel_1/
│   ├── fantasy_hotel_2/
│   ├── fantasy_office_building_1/
│   ├── fantasy_office_building_2/
│   ├── fantasy_office_building_3/
│   ├── fantasy_residential_building_1/
│   ├── fzk_house/
│   ├── hitos/
│   ├── molio/
│   ├── samuel_macalister_sample_house/
│   ├── schependomlaan/
│   ├── sixty5/
│   ├── smiley_west/
│   └── wbdg_office/
│       ├── arc.ifc            # IFC model files
│       ├── model_card.md      # Project metadata
│       ├── license.txt        # Model license
│       └── snapshot.png       # Visual snapshot
├── questions/
│   ├── ifc-bench-v2.csv       # V2 dataset (1,027 QA pairs)
│   └── ifc-bench-v1.csv       # V1 dataset (preserved)
└── docs/
    └── CONTRIBUTING.md
```

## Models Overview

| Project | Disciplines | License | Usage | Source |
|---------|-------------|---------|-------|--------|
| `4351` | Architecture | GNU GPL v3 | unspecified | [BIMserver TestFiles](https://github.com/opensourceBIM/TestFiles) |
| `ac20` | Architecture | CC BY 4.0 | office | [KIT IFC Examples](https://www.ifcwiki.org/index.php?title=KIT_IFC_Examples) |
| `city_house_munich` | Architecture | CC BY 4.0 | living | N/A |
| `dental_clinic` | Architecture, Structural, MEP | CC BY 4.0 | healthcare | [buildingSMART](https://github.com/buildingsmart-community/Community-Sample-Test-Files) |
| `digital_hub` | Architecture, Heating, Plumbing, Ventilation | MIT | office | [RWTH E3D](https://github.com/RWTH-E3D/DigitalHub) |
| `duplex` | Architecture, MEP | CC BY 4.0 | living | [buildingSMART](https://github.com/buildingsmart-community/Community-Sample-Test-Files) |
| `ettenheim_gis` | GIS | GNU GPL v3 | mix | [BIMserver TestFiles](https://github.com/opensourceBIM/TestFiles) |
| `fantasy_hotel_1` | Architecture | MIT | hospitality | TUM BIM Fundamentals SS2025 |
| `fantasy_hotel_2` | Architecture | MIT | hospitality | TUM BIM Fundamentals SS2025 |
| `fantasy_office_building_1` | Architecture | MIT | office | TUM BIM Fundamentals SS2025 |
| `fantasy_office_building_2` | Architecture | MIT | office | TUM BIM Fundamentals SS2025 |
| `fantasy_office_building_3` | Architecture | MIT | office | TUM BIM Fundamentals SS2025 |
| `fantasy_residential_building_1` | Architecture | MIT | living | TUM BIM Fundamentals SS2025 |
| `fzk_house` | Architecture | CC BY 4.0 | living | [KIT IFC Examples](https://www.ifcwiki.org/index.php?title=KIT_IFC_Examples) |
| `hitos` | Architecture | GNU GPL v3 | office | [BIMserver TestFiles](https://github.com/opensourceBIM/TestFiles) |
| `molio` | Architecture | CC BY 4.0 | office | [buildingSMART](https://github.com/buildingsmart-community/Community-Sample-Test-Files) |
| `samuel_macalister_sample_house` | Architecture, MEP | GNU GPL v3 | living | [BIMserver TestFiles](https://github.com/opensourceBIM/TestFiles) |
| `schependomlaan` | Architecture | CC BY 4.0 | living | [openBIM Archive](https://github.com/openBIMstandards/Archive-DataSetSchependomlaan) |
| `sixty5` | Architecture, Electrical, Facade, Kitchen, Plumbing, Structural, Ventilation | CC BY 4.0 | living | [buildingSMART](https://github.com/buildingsmart-community/Community-Sample-Test-Files) |
| `smiley_west` | Architecture | CC BY 4.0 | living | [KIT IFC Examples](https://www.ifcwiki.org/index.php?title=KIT_IFC_Examples) |
| `wbdg_office` | Architecture, MEP, Structural | CC BY 4.0 | office | [WBDG](https://www.wbdg.org/bim/cobie/common-bim-files) |

<table>
  <tr>
    <td align="center"><img src="projects/4351/snapshot.png" width="250"/><br><b>4351</b></td>
    <td align="center"><img src="projects/ac20/snapshot.png" width="250"/><br><b>ac20</b></td>
    <td align="center"><img src="projects/city_house_munich/snapshot.png" width="250"/><br><b>city_house_munich</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/dental_clinic/snapshot.png" width="250"/><br><b>dental_clinic</b></td>
    <td align="center"><img src="projects/digital_hub/snapshot.png" width="250"/><br><b>digital_hub</b></td>
    <td align="center"><img src="projects/duplex/snapshot.png" width="250"/><br><b>duplex</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/ettenheim_gis/snapshot.png" width="250"/><br><b>ettenheim_gis</b></td>
    <td align="center"><img src="projects/fantasy_hotel_1/snapshot.png" width="250"/><br><b>fantasy_hotel_1</b></td>
    <td align="center"><img src="projects/fantasy_hotel_2/snapshot.png" width="250"/><br><b>fantasy_hotel_2</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/fantasy_office_building_1/snapshot.png" width="250"/><br><b>fantasy_office_building_1</b></td>
    <td align="center"><img src="projects/fantasy_office_building_2/snapshot.png" width="250"/><br><b>fantasy_office_building_2</b></td>
    <td align="center"><img src="projects/fantasy_office_building_3/snapshot.png" width="250"/><br><b>fantasy_office_building_3</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/fantasy_residential_building_1/snapshot.png" width="250"/><br><b>fantasy_residential_building_1</b></td>
    <td align="center"><img src="projects/fzk_house/snapshot.png" width="250"/><br><b>fzk_house</b></td>
    <td align="center"><img src="projects/hitos/snapshot.png" width="250"/><br><b>hitos</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/molio/snapshot.png" width="250"/><br><b>molio</b></td>
    <td align="center"><img src="projects/samuel_macalister_sample_house/snapshot.png" width="250"/><br><b>samuel_macalister_sample_house</b></td>
    <td align="center"><img src="projects/schependomlaan/snapshot.png" width="250"/><br><b>schependomlaan</b></td>
  </tr>
  <tr>
    <td align="center"><img src="projects/sixty5/snapshot.png" width="250"/><br><b>sixty5</b></td>
    <td align="center"><img src="projects/smiley_west/snapshot.png" width="250"/><br><b>smiley_west</b></td>
    <td align="center"><img src="projects/wbdg_office/snapshot.png" width="250"/><br><b>wbdg_office</b></td>
  </tr>
</table>

## Question Taxonomy

Questions are classified into 4 categories based on data retrieval complexity and computational requirements, adapted from the classification framework by [Solihin et al. (2015)](https://doi.org/10.1016/j.autcon.2015.03.004) for automated BIM compliance checking.

| Category | Name | Count | Description |
|----------|------|-------|-------------|
| 1 | Direct Information Retrieval | 152 | Answerable through direct access to explicitly stored BIM element properties, without requiring computation. |
| 2 | Computational Aggregation | 569 | Require simple, unambiguous mathematical operations (counting, summation, averaging, filtering) on directly accessible data. |
| 3 | Geometric/Spatial Computation | 112 | Require complex computations involving geometric properties, spatial relationships, or derived measurements not directly stored. |
| 4 | Incomplete Information | 194 | The required information is not fully available in the BIM model; answering requires assumptions or acknowledging limitations. |

For details on how the taxonomy is used in evaluation, see:

> Hellin, S., Nousias, S., & Borrmann, A. (2026). *Evaluating AI Systems for BIM Information Retrieval: A Multi-Dimensional Framework Beyond Binary Accuracy.* GNI 2026.

## Getting Started

### Prerequisites
- Python 3.8+
- [uv](https://github.com/astral-sh/uv) (recommended for virtual environment management)

### Quick Start

```bash
git clone https://github.com/sylvainHellin/ifc-bench.git
cd ifc-bench

# Install dependencies (using uv)
uv pip install pandas ifcopenshell
```

### Using the Dataset

```python
import pandas as pd

# Load V2 dataset
df = pd.read_csv('questions/ifc-bench-v2.csv')

print(f"Total QA pairs: {len(df)}")
print(f"Projects: {df['project'].nunique()}")
print(f"Category distribution:\n{df['category'].value_counts().sort_index()}")

# Filter by category
spatial_questions = df[df['category'] == 3]
print(f"\nGeometric/Spatial questions: {len(spatial_questions)}")

# Filter by project
duplex_questions = df[df['project'] == 'duplex']
print(f"Duplex questions: {len(duplex_questions)}")
```

### Dataset Columns

| Column | Description | Example |
|--------|-------------|---------|
| `question` | Natural language question about a BIM model | "What is the total gross floor area of the building?" |
| `ground_truth` | Reference answer | "The total gross floor area is 354.67 sqm" |
| `ifc_model` | Model filename (without `.ifc` extension) | "arc" |
| `project` | Project name (matches directory under `projects/`) | "duplex" |
| `category` | Question complexity category (1-4) | 2 |

## Dataset Integrity

Verify dataset integrity using SHA-256 checksums:

```bash
# V2 dataset
shasum -a 256 questions/ifc-bench-v2.csv
# Expected: 8f08f5d04834a79310eb7de81f2d6812e74d53a01363affdb815bf86dfc4dbf4

# V1 dataset (preserved for backwards compatibility)
shasum -a 256 questions/ifc-bench-v1.csv
# Expected: f67a48770d74b6e0ff0868c923c3e1d976110350b2c439564d7ceccc16a46f35
```

## Contributing

We welcome contributions:
- New IFC models (with permissive licensing)
- Additional QA pairs for existing models
- Documentation improvements
- Error corrections in existing answers

Please see our [Contribution Guidelines](docs/CONTRIBUTING.md) for details.

## License

- **Dataset** (question-answer pairs, documentation, model cards, and all original content): Licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
- **IFC models**: Each model retains its original license as specified in its project's `license.txt`. The majority of models are licensed under CC BY 4.0 or MIT. However, the following models are licensed under **GNU GPLv3** and are subject to its copyleft terms:
  - `4351`, `ettenheim_gis`, `hitos`, `samuel_macalister_sample_house` (source: [BIMserver TestFiles](https://github.com/opensourceBIM/TestFiles))

  Users who redistribute or create derivative works that include these GPLv3 model files must comply with the GPLv3 license terms for those files. See each project's `license.txt` for details.

## Citation

If using in research, please cite:

```bibtex
@inproceedings{hellinNaturalLanguageInformation2025,
  title = {Natural {{Language Information Retrieval}} from {{BIM Models}}: {{An LLM-Based Agentic Workflow Approach}}},
  booktitle = {{{EC3}}},
  author = {Hellin, Sylvain and Nousias, Stavros and Borrmann, Andr{\'e}},
  year = 2025,
  doi = {http://www.doi.org/10.35490/EC3.2025.265},
  abstract = {While Building Information Models (BIM) effectively store building-related information, accessing it requires specialized software and expertise. Natural Language (NL) interfaces for BIM data retrieval can mitigate this challenge, but existing approaches are limited by rigid ontological frameworks or extensive pre-processing requirements. We present a Large Language Model-based agentic workflow that processes NL queries and automatically interacts with IFC-encoded BIM models without ontological or pre-processing constraints. In tests across architectural, structural, and MEP domains, our approach achieves 80\% overall accuracy. We provide open access to IFC-Bench-v1, our evaluation dataset containing various queries, answers, and reference BIM models.},
  copyright = {CC0 1.0 Universal Public Domain Dedication},
  langid = {english}
}
```

## Acknowledgments

- [buildingSMART International](https://www.buildingsmart.org/) for providing sample files
- [RWTH Aachen University E3D Institute](https://github.com/RWTH-E3D) for the Digital Hub models
- [KIT IAI](https://www.ifcwiki.org/) for IFC example models
- Tamira Wrabel, Sebastian Esser and Zijian Wang for preparing and curating the BIM Fundamentals SS2025 student models
- TUM BIM Fundamentals SS2025 students for fantasy building models
- [Selahattin Doelger](https://github.com/buildingsmart-community/Community-Sample-Test-Files) for the Sixty5 models
- The openBIM community for quality assurance

---

**Maintainer**: Sylvain Hellin | **Contact**: [sylvain.hellin@tum.de](mailto:sylvain.hellin@tum.de) | **Issues**: [GitHub Issues](https://github.com/sylvainHellin/ifc-bench/issues)