BIM Georeferencing Audit Script (ArcPy)

Overview

This repository contains a Python (ArcPy) script that audits georeferencing metadata for BIM files stored in a folder structure.
The script recursively scans Revit (.rvt) and IFC (.ifc) files, extracts recorded spatial reference (CRS) information and exterior model extents, evaluates georeferencing readiness, and generates a timestamped, human‑readable text report.

The output is intended to support BIM intake validation, BIM‑to‑GIS workflows, and vendor quality assurance prior to integrating BIM data into GIS environments such as ArcGIS Pro.

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What the Script Reports

For each BIM file, the report includes:

• File name
• BIM data type (Revit / IFC)
• Georeferencing status (Georeferenced vs. Un‑Georeferenced)
• Recorded spatial reference (CRS)
• EPSG Code
• Version of the File
• ExteriorShell model extents (X, Y, Z)
• A summary section highlighting un‑georeferenced models
• A timestamp and disclaimer clarifying data responsibility
• Display Unit System
• Length Display Unit
• Model Length Unit

Important
The report reflects only the spatial reference and extent information recorded in the BIM file.
Vendors are responsible for ensuring that georeferenced data is correct for the project location.

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Requirements

• ArcGIS Pro (3.6 recommended)
• Python 3.x (installed with ArcGIS Pro)
• ArcPy (comes with ArcGIS Pro)
• Read access to the folder containing BIM files (.rvt, .ifc)

No third‑party Python packages are required.

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🚀 Key Features

• ✅ Recursively scans a workspace folder for:
  • Autodesk Revit files (.rvt)
  • IFC files (.ifc)
• ✅ Reports per BIM file:
  • CRS name
  • EPSG code (when available)
  • Spatial extent:
    • XMin
    • YMin
    • XMax
    • YMax
  • Georeferencing status
  • IFC length unit (IFC only)
• ✅ Output options:
  • Console report
  • Optional text (.txt) report
• ✅ Separate reports:
  • FULL BIM Report (all files)
  • UN‑GEOREFERENCED ONLY Report
• ✅ Designed for ArcGIS Pro Notebook execution
• ✅ Vendor‑neutral and standards‑focused

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📂 Supported File Types

File Type	Supported	Notes
.rvt	✅	CRS & spatial extent only
.ifc	✅	CRS, extent, length unit extracted
Other	❌	Ignored

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Usage

Option 1: Run as a Python Script

1. Open an ArcGIS Pro Python environment or ArcGIS Pro Notebook
2. Update the workspace variable in the script to point to your BIM folder
3. Run the script
4. When prompted, choose whether to save the report to a text file

A timestamped .txt report will be generated in the workspace folder by default.

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Option 2: Run as an ArcGIS Pro Script Tool

The script can be added to a custom toolbox in ArcGIS Pro and configured to accept:

• Input folder
• Output report path

This option is recommended for repeated use or distribution to non‑developers.

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Typical Use Cases

• BIM georeferencing QA checks
• BIM delivery validation from vendors
• Pre‑processing checks before BIM‑to‑GIS integration
• Identifying BIM files missing CRS or exterior geometry
• Supporting infrastructure and AEC GIS workflows

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📑 Generated Reports

This script can generate two separate text files:

1️⃣ Full BIM Report

Includes all detected BIM files.

Default:

BIM_Report_.txt

2️⃣ Un‑Georeferenced BIM Report

Includes only files flagged as UN‑GEOREFERENCED.

Default:

BIM_UnGeoreferenced_Report_.txt

The un‑georeferenced report is offered only if applicable files exist.

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📝 Text Output Behavior

• Default output filename:

  BIM_Report_.txt
  

• The user may:
  • Accept the default location
  • Specify a custom path
• The script will:
  • Attempt to create directories if missing
  • Warn the user if file permissions prevent saving

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📏 IFC Length Unit Reporting

• Length units are extracted only for IFC files
• Detection is based on parsing readable IFC text
• Typical reported values:
  • METERS
  • MILLIMETERS
  • FEET
• For Revit models:

  Length Unit: N/A
  

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⚠️ Important Disclaimer

The report only displays the spatial reference and extent information recorded in the BIM file.
It does not validate whether the georeferenced data aligns correctly with the intended real‑world project location.
Ensuring correct georeferencing remains the responsibility of the data provider or vendor.

This tool performs metadata‑level validation only.

• It does not verify real‑world spatial accuracy
• CRS values may exist but be incorrectly assigned
• Spatial extents may fall outside valid CRS bounds
• IFC parsing depends on accessible text content

⚠️ Results should always be validated against project control, survey data, and authoritative GIS references.

This script must not be used as a substitute for professional surveying or engineering review.