Agent skill · data analytics · datadrivenconstruction
ifc-qto-extraction
Extract quantities from IFC/Revit models for quantity takeoff. Uses DDC converters to get element counts, areas, volumes, lengths with grouping and reporting.
Why this skill is useful
Provides specific commands and workflows for extracting structured quantity data from BIM models that the AI wouldn't reliably generate on its own.
What it needs
Requires ifcopenshell, python3 installed locally. About 7k tokens when loaded. Last updated 2026-02-14. 265 stars on the source repository.
What this skill does
IFC Quantity Takeoff Extraction Extract structured quantity data from BIM models (IFC, Revit) for cost estimation, material ordering, and progress tracking. Business Case Problem: Manual quantity takeoff is: Time-consuming (40-80 hours for medium project) Error-prone (human counting mistakes) Not repeatable (changes require full rework) Disconnected from design (no live updates) Solution: Automated QTO from BIM that: Extracts all quantities in minutes Groups by type, level, zone Updates instantly with model changes Exports to Excel for pricing ROI: 90% reduction in QTO time, near-zero counting errors DDC Tools Used CLI Commands Revit to Excel (with BBox for volumes) IFC to Excel DWG to Excel (2D areas) Python Implementation n8n Workflow Integration Best Practices 1. Model Quality: Ensure BIM model has proper levels and types assigned 2. Units: Verify model units match expected output units 3. Categories: Use consistent category naming for grouping 4. Updates: Re-run QTO after design changes 5. Validation: Cross-check totals against manual spot checks Common Quantity Formulas --- "Measure twice, cut once. Or better yet, measure automatically from the model."
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills datadrivenconstruction/ifc-qto-extraction