(moved from a from a comment in #344, since this issue is probably different and less common)

Here is an example where SimpleBIM seems to be the only viewer that seems to handle this file close to what the architect meant in Revit: 359--wall--wrong-geometry--augmented.ifc

I guess this is quite a non-standard-way of modeling so this may not be a very important issue.

Here is the output with IfcOpenShell e87a1a0 (OCCT 7.2.0):

This is the view of the wall from the architect in Revit:

This is how the wall looks in SimpleBIM:

Solibri seems to struggle a bit:

DDS seems to struggle even more: