BIM Georeferencing Validation

Spatial Reference & Extent Validation for BIM (IFC / Revit) Reports

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Overview

This repository contains a Python utility that inspects and validates BIM georeferencing metadata as reported by ArcGIS Pro (or similar tools).

The script checks whether the recorded coordinate reference system (CRS) and model extents fall within the valid EPSG Area of Use for the declared CRS. It supports both projected and geographic coordinate systems and produces a structured JSON report suitable for QA workflows.

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Disclaimer

This tool validates only what is recorded in the file.

It does NOT verify:

• Real‑world alignment
• Survey accuracy
• Authoring intent
• Correctness of transformations applied in upstream software

Passing validation indicates that recorded extents fall within the expected CRS domain — not that the BIM model is correctly georeferenced in reality.

The data producer remains responsible for spatial correctness.

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Features

• Parses BIM georeferencing reports (.txt)
• Resolves CRS using:
  • ESRI spatial reference names
  • Automatic EPSG inference from WKT (fallback)
• Dynamically loads CRS Area of Use from the EPSG registry
• Validates extents against CRS domain
• Supports projected and geographic CRSs
• Outputs structured JSON results with diagnostics

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Input

A plain‑text BIM georeferencing report (typically from ArcGIS Pro) containing fields such as:

• BIM File
• SpatialReference
• SpatialReference WKT (optional)
• ExteriorShell Extent (XMin, YMin, XMax, YMax, ZMin, ZMax)

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Output

A JSON file written alongside the input report:

Example Output

{
  "BIM_File": "bridge.ifc",
  "Declared_SpatialReference": "ETRS_1989_UTM_Zone_31N",
  "EPSG": 25831,
  "CRS_Type": "Projected",
  "Unit": "metre",
  "CRS_AreaOfUse": "Between 0°E and 6°E, northern hemisphere",
  "Extent_Status": "INSIDE",
  "Diagnostics": [
    "EPSG inferred from WKT definition (EPSG:25831)."
  ]
}