Warning · Classification
How to fix Missing classification
in IFC files
Attach a classification reference (Uniclass, OmniClass, etc.) so the element carries its standard code as IfcRelAssociatesClassification.
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No account · No upload · Runs in your browser · 44 validation checks
What it means
The Missing classification check
Physical element has no IfcRelAssociatesClassification
The fix
How to fix Missing classification in your authoring tool
Concrete, tool-specific steps. The check itself is schema-agnostic and works for IFC2x3, IFC4, IFC4x1 and IFC4x3.
| Authoring tool | How to fix |
|---|---|
| Revit | Use a classification add-in (e.g. the free Classification Manager for Revit) to assign a Uniclass/OmniClass code, or map a shared parameter to IfcClassificationReference in the IFC export setup. Without a mapping Revit exports no classification. |
| ArchiCAD | Open the Classification & Properties palette, choose a classification system (built-in or imported), and assign the element a classification item. ARCHICAD exports these as IfcClassificationReference automatically. |
| Tekla | Assign the classification via a UDA or the Tekla–IFC property mapping, then map that attribute to IfcClassificationReference in the IFC export additional property sets. |
| Allplan | Assign the classification code through the object attributes and ensure the IFC export configuration maps it to IfcClassificationReference. |
How it works
Find and fix it in the browser
The whole flow runs client-side — your IFC file never leaves your machine.
01
Open your IFC file
Open IFC Viewer Online and drag & drop your IFC file. It is parsed locally in your browser via WebAssembly — nothing is uploaded.
02
Run the Health Score validation
Run validation. The "Missing classification" check (RULE_MISSING_CLASSIFICATION) flags every affected element and pinpoints it in the model tree.
03
Re-validate
Re-export from your authoring tool and re-run validation to confirm the issue is resolved and your Health Score improved.
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