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 · 38 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
Fix in 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…
04
Fix in ArchiCAD
Open the Classification & Properties palette, choose a classification system (built-in or imported), and assign the element a classification item.…
05
Fix in Tekla
Assign the classification via a UDA or the Tekla–IFC property mapping, then map that attribute to IfcClassificationReference in the IFC export…
06
Fix in Allplan
Assign the classification code through the object attributes and ensure the IFC export configuration maps it to IfcClassificationReference.
07
Re-validate
Re-export from your authoring tool and re-run validation to confirm the issue is resolved and your Health Score improved.
Check your whole model, not just one rule.
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