IfcLCA-Py

IfcLCA-Py is a Python package for performing Life Cycle Assessment (LCA) on building models using Industry Foundation Classes (IFC) files. It provides a comprehensive toolkit for analyzing the environmental impact of construction projects.

Features

• IFC Model Analysis: Extract materials and quantities from IFC files
• Multi-Database Support: Built-in support for KBOB (Swiss) and ÖKOBAUDAT (German) databases
• Environmental Indicators: Calculate GWP (Global Warming Potential), PEnr (Primary Energy), and UBP (Environmental Impact Points)
• Material Mapping: Automatic and manual mapping of IFC materials to environmental databases
• Optioneering: Compare different material options to optimize environmental performance
• Comprehensive Reporting: Generate reports in text, CSV, and JSON formats
• Blender Integration: Full integration available via IfcLCA-blend add-on

Installation

pip install ifclca

Or install from source:

git clone https://github.com/IfcLCA/IfcLCA-Py.git
cd IfcLCA-Py
pip install -e .

Quick Start

import ifcopenshell
from IfcLCA import IfcLCA, KBOBReader, IfcLCAReporter

# Load IFC file
ifc_file = ifcopenshell.open("building.ifc")

# Initialize database and LCA interface
db_reader = KBOBReader()  # Uses built-in KBOB data
lca = IfcLCA(ifc_file, db_reader)

# Discover and map materials
materials = lca.get_all_materials()
mapping = lca.auto_map_materials()

# Run analysis
analysis = lca.run_analysis(mapping)

# Generate report
reporter = IfcLCAReporter("My Building")
report = reporter.generate_analysis_report(analysis, 'text')
print(report)

Detailed Usage

1. Loading IFC Files

import ifcopenshell
ifc_file = ifcopenshell.open("path/to/building.ifc")

2. Database Selection

KBOB (Swiss database) - Built-in:

from IfcLCA import KBOBReader
db_reader = KBOBReader()  # Uses default KBOB 2022 data
# Or load custom KBOB JSON:
db_reader = KBOBReader("path/to/custom_kbob.json")

ÖKOBAUDAT (German database):

from IfcLCA import OkobaudatReader
db_reader = OkobaudatReader("path/to/OEKOBAUDAT.csv")

3. Material Discovery and Mapping

from IfcLCA import IfcLCA

# Initialize
lca = IfcLCA(ifc_file, db_reader)

# Validate model
validation = lca.validate_model_for_lca()
if not validation['valid']:
    print("Warnings:", validation['warnings'])

# Get all materials
materials = lca.get_all_materials()
for mat_name, count, mat_type in materials:
    print(f"{mat_name}: {count} elements ({mat_type})")

# Auto-map materials
mapping = lca.auto_map_materials()

# Or manual mapping
mapping = {
    "Concrete C30/37": "KBOB_CONCRETE_C30_37",
    "Steel": "KBOB_STEEL_STRUCTURAL"
}

4. Running Analysis

# Run analysis
analysis = lca.run_analysis(mapping)

# Get results by indicator
results = analysis.get_results_by_indicator()
print(f"Total GWP: {sum(results['gwp'].values()):.1f} kg CO₂-eq")
print(f"Total PEnr: {sum(results['penr'].values()):.0f} MJ")

# Get detailed results
detailed = analysis.get_detailed_results()
for material, details in detailed.items():
    print(f"{material}: {details['gwp']:.1f} kg CO₂-eq")

5. Optioneering

from IfcLCA import IfcLCAOptioneering

# Create optioneering analysis
opt = IfcLCAOptioneering(ifc_file, db_reader, mapping)

# Add alternatives
opt.add_substitution_rule({
    'name': 'Low Carbon Concrete',
    'description': 'Use recycled concrete',
    'substitutions': {
        'Concrete C30/37': 'KBOB_CONCRETE_RC'
    }
})

# Compare material options
opt.add_material_comparison(
    'Concrete C30/37',
    ['KBOB_CONCRETE_C25_30', 'KBOB_CONCRETE_RC'],
    name="Concrete Alternatives"
)

# Run and get results
results = opt.run()
print(opt.generate_report())

6. Reporting

from IfcLCA import IfcLCAReporter

reporter = IfcLCAReporter("Project Name")

# Generate different formats
text_report = reporter.generate_analysis_report(analysis, 'text')
csv_report = reporter.generate_analysis_report(analysis, 'csv')
json_report = reporter.generate_analysis_report(analysis, 'json')

# Save reports
reporter.save_report(text_report, 'report.txt')

# Get visualization data
viz_data = reporter.generate_visualization_data(analysis)
# Use viz_data with your preferred charting library

IFC Requirements

For best results, your IFC file should include:

• Material assignments: Using IfcMaterial, IfcMaterialLayerSet, or IfcMaterialConstituentSet
• Quantities: BaseQuantities with GrossVolume or NetVolume
• Proper units: IfcUnitAssignment for correct scaling

Environmental Indicators

The package calculates three main indicators:

• GWP (Global Warming Potential): kg CO₂-equivalent
• PEnr (Primary Energy non-renewable): MJ
• UBP (Environmental Impact Points): Swiss Eco-points

Database Format

KBOB JSON Format

{
  "MATERIAL_ID": {
    "name": "Material Name",
    "category": "Category",
    "density": 2400,
    "gwp": 0.1,
    "penr": 1.0,
    "ubp": 120,
    "unit": "kg"
  }
}

ÖKOBAUDAT CSV Format

The CSV should include columns for:

• ID/UUID
• Name
• Category
• Density (kg/m³)
• GWP-total or GWP100
• PENRT or PENR
• Unit reference

Advanced Features

Custom Element Filtering

from IfcLCA.utils import selector

# Filter by complex criteria
elements = selector.filter_elements(ifc_file, {
    'ifc_class': 'IfcWall',
    'material': 'Concrete*',
    'property': {'IsExternal': True}
})

Material Layer Analysis

# Get detailed material information
for element in ifc_file.by_type('IfcElement'):
    materials = selector.get_element_materials(element)
    for mat_info in materials:
        print(f"Material: {mat_info['name']}")
        if mat_info['layer_thickness']:
            print(f"  Layer thickness: {mat_info['layer_thickness']}")
        if mat_info['fraction']:
            print(f"  Fraction: {mat_info['fraction']}")

Examples

See the examples/ directory for:

• comprehensive_example.py: Full workflow demonstration
• Integration with Blender via IfcLCA-blend

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE file for details.

Acknowledgments

• IfcOpenShell community for the excellent IFC toolkit
• KBOB and ÖKOBAUDAT for providing open environmental data