Autodesk / Autodesk/revit-ifc

PR: Room geometry shifted in IFC Exporter 25.4.40.17 + 25.4.41.5 + 26.4.0.16 + 26.4.0.32

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C#
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Description

### Problem Description

During export, spaces are not created correctly. The problem from version 25.4.3 of incorrect room heights, see also Issue #891 here,
still exists. In addition, some spaces are completely shifted in their spatial position.
We have tested this in 3 different models.

In the first model, 2 spaces are shifted. The elongated space is inside the building, while the other has been moved outside the building and has even changed shape. The red spaces were created with IFC Exporter 25.4.20.11, while the blue, displaced spaces were created with IFC Exporter 25.4.40.17.

Image

In the second model, two spaces were moved outside the building. The shape of the spaces remained unchanged. The model with the moved spaces was created with IFC Exporter 25.4.41.5. The other was created with IFC Exporter 25.4.30.30

Image

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In the third model, a large number of spaces were moved. The shape of the spaces remained unchanged. The faulty model was created with IFC-Exporter 25.4.41.5. The other was created with IFC-Exporter 25.4.30.30.

Image

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In IFC-versions 26.4.0.16 and 26.4.0.32, the behavior of the moved spaces also occurs. Only in version 26.1.0.23 are the spaces not moved. However, in this version, the problem with incorrectly exported room heights still exists (Issue #891)

### Revit Version

2025.4.x

### IFC for Revit Addon Version

25.4.0

### Windows Version

11 23H2

Contributor guide

Open the contributing guide

Research direction

Reproduce the IFC exports using the reported Revit and IFC Exporter versions, comparing the affected space positions and room heights across the supplied model cases. Read Issue #891 alongside this report to separate the existing height problem from the newly shifted geometry. Done means exported spaces retain their expected shapes, positions, and heights in the affected versions.

Written by the indexing model from the issue text.

Assessment

Tech stack
csharp
Domain
desktop
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
42/100

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