Problem Description

Looks like any roombounding object that defines the top or bottom of a room is no longer taken into account when exporting room geometry using the 25.4.3 exporter. Tried this with both IFC2x3 CV2 and IFC4 RVArch.

Here's what I get when comparing export results from 25.4.0 and 25.4.3 (red IfcSpace entities are from 25.4.0):

Revit Version

2025.4.x

IFC for Revit Addon Version

25.4.0

Windows Version

11 24H2