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BIM Best Practices · 2026-06-03 · 12 min
The Complete Guide to IFC Quality: From Export to Delivery
Every BEP demands a 'quality IFC' and almost none define it. This is the complete, practical guide to what IFC quality actually means — the failure categories that get models rejected, how to check each one, and a repeatable workflow that gets you to a deliverable file.
The Complete Guide to IFC Quality: From Export to Delivery — IFC Viewer Online article cover
If you only read one article on IFC quality, make it this one. It ties together every failure mode that gets a model rejected at the Common Data Environment — and links out to the detailed fix for each. The goal is simple: a file you can deliver with confidence, every time, without surprises three weeks into coordination.
'IFC quality' isn't one thing. It's six categories of failure, each with its own causes, detection, and fix. Understand the map and the rest is mechanical.
- 6 — failure categories
- 44 — validation rules
- 80+ — Health Score to deliver
- 30s — to validate any model
Two Layers: Schema Validity vs Practical Health
First, the distinction that confuses everyone. Schema validity means the file conforms to the IFC standard's syntax and structure. Practical health means it'll actually work downstream — stable identities, sound hierarchy, sensible coordinates, present data. A file can be schema-valid and practically broken. Most rejected deliveries are schema-valid. For how to check each layer, see How to Validate an IFC File Before You Send It.
The Six Failure Categories
1. Identity (GUIDs)
Duplicate, regenerated, or out-of-range GlobalIds break BCF, clash tracking, and FM handover. Identity must be stable across revisions.
2. Spatial hierarchy
Project → Site → Building → Storey → elements. Orphans, wrong containers, broken aggregates, or a missing IfcProject corrupt the tree.
3. Coordinates
Models kilometres from the origin, or with the wrong base/survey point, place geometry wrong and can distort it via floating-point error.
4. Data & properties
Missing property sets, empty names, and unmapped proxies make the model unusable for takeoff, BCF, and asset registers.
5. Geometry & export
Wrong-floor placement, import-vs-link mangling, and proxy overuse — usually traceable to Revit/ArchiCAD export settings.
6. Performance & size
1 GB monolithic files that crash viewers. Trim by discipline, prefer IFC4, and use a convert-once pipeline.
Category 1: Identity
GlobalIds are the permanent identity of every element. They must be unique within a file, valid in format (22 chars, leading character 0–3), and stable across re-exports. See Duplicate GUIDs in IFC and Why IFC GUIDs Change on Every Export for detection and fixes.
Category 2: Spatial Hierarchy
IFC mandates a strict containment order. Elements must sit inside a storey, there must be exactly one IfcProject, and aggregate relationships must point at entities that exist. The detailed checklist is in The 7 Most Common IFC Validation Errors.
Category 3: Coordinates
Export with Shared Coordinates, keep the model near the world origin, and for georeferenced projects make sure IfcSite, IfcProjectedCRS, and IfcMapConversion are present and consistent. Full breakdown in IFC Coordinates Are Wrong.
Category 4: Data & Properties
Enable standard property sets, name every element, and map families to proper IFC classes so they don't export as proxies. See IFC Properties Missing After Export From Revit.
Category 5: Geometry & Export
Most geometry failures originate in the authoring tool's export settings. See How to Export Clean IFC Files from Revit, Why Your Revit IFC Export Breaks, and — for cross-tool exchange — Revit ↔ Archicad via IFC.
Category 6: Performance & Size
Large files aren't a quality failure per se, but they block everyone downstream. Trim, prefer IFC4 tessellation, and use a convert-once viewer. See Why Large IFC Files Crash Your Browser.
The Health Score: One Number Across All Six
A Health Score collapses all six categories into a single 0–100 number, severity-weighted and logarithmic, so it reflects real fitness rather than raw issue count. It's the number to put in your BEP and attach to every transmittal.
- 43/100 — Critical — do not deliver
- 73/100 — Needs work
- 87/100 — CDE ready
- 96/100 — Excellence
The Repeatable Pre-Delivery Workflow
- Configure export settings once (Keep Existing GUIDs, Shared Coordinates, standard Psets, Building Story flags).
- Export to a local folder, never straight to the CDE.
- Open the file in a validator and read the report across all six categories.
- Fix at the source in the authoring tool, then re-export — not by editing the IFC text.
- Re-validate until Health Score ≥ 80.
- Attach the score to the transmittal and deliver.
Run the full quality check
Open a real model and see all six categories scored in one report. Then drop in your own file and walk the pre-delivery workflow end to end.
IFC2x3 · 2.4 MB
Open the interactive IFC viewer
The Complete Guide to IFC Quality: From Export to Delivery