Estimate embodied carbon (CO2e) for grouped BIM/CAD elements. The workflow accepts an existing XLSX (grouped element data) or, if missing, can trigger a local RvtExporter.exe to generate one. It detects category fields, filters out non-building elements, infers aggregation rules with AI, computes CO2 using densities & emission factors, and exports a multi-sheet Excel plus a clean HTML report. What it does - Reads or builds XLSX (from your model via RvtExporter.exe when needed). - Finds category/volumetric fields; separates building vs. annotation elements. - Uses AI to infer aggregation rules (sum/mean/first) per header. - Groups rows by your groupby field and aggregates totals. - Prepares enhanced prompts and calls your LLM to classify materials and estimate CO2 (A1-A3 minimum). - Computes project totals and generates a multi-sheet XLSX + HTML report with charts and hotspots. Prerequisites - LLM credentials for one provider (e.g., OpenAI, Anthropic, Gemini, Grok/OpenRouter). Enable one chat node and connect credentials. - Windows host only if you want to auto-extract from .rvt/.ifc via RvtExporter.exe. If you already have an XLSX, Windows is not required. - Optional: mapping/classifier files (XLSX/CSV/PDF) to improve material classification. How to use 1. Import this JSON into n8n. 2. Open the Setup/Parameters node(s) and set: - projectfile — path to your .rvt/.ifc or to an existing grouped rvt.xlsx - pathtoconverter — C:\\DDCConverterRevit\\datadrivenlibs\\RvtExporter.exe (optional) - groupby — e.g., Type Name / Category / IfcType - sheetname — default Summary (if reading from XLSX) 3. Enable one LLM node and attach credentials; keep others disabled. 4. Execute (Manual Trigger). The workflow detects/builds the XLSX, analyzes, classifies, estimates CO2, then writes Excel and opens the HTML report. Outputs - Excel (CO2AnalysisReportYYYY-MM-DD.xlsx, 8 sheets): Executive Summary, All Elements, Material Summary, Category Analysis, Impact Analysis, Top 20 Hotspots, Data Quality, Recommendations. - HTML: executive report with key KPIs and charts. - Per-group fields include: Material (EU/DE/US), Quantity & Unit, Density, Mass, CO2 Factor, Total CO2 (kg/tonnes), CO2 %, Confidence, Assumptions. Notes & tips - Input quantities (volumes/areas) are already aggregated per group — do not multiply by element count. - Use -no-collada upstream if you only need XLSX in extraction. - Prefer ASCII-safe paths and ensure write permissions to output folder. Categories Data Extraction · Files & Storage · ETL · CAD/BIM · Carbon/ESG Tags cad-bim, co2, carbon, embodied-carbon, lca, revit, ifc, xlsx, html-report, llm Author DataDrivenConstruction.io info@datadrivenconstruction.io Consulting and Training We work with leading construction, engineering, consulting agencies and technology firms around the world to help them implement open data principles, automate CAD/BIM processing and build robust ETL pipelines. If you would like to test this solution with your own data, or are interested in adapting the workflow to real project tasks, feel free to contact us. Docs & Issues: Full Readme on GitHub
