Problems with Base Quantities in several cases

zsoka biro — Fri, 05 Jul 2024 18:24:26 GMT

We are currently setting up a workflow to measure the sustainability of our planned buildings. The workflow is based on IFC4 Data Exchange, and the LCA-Software is using the BaseQuantites for measurements (there are currently no options to use a custom property). This workflow shed ligth on a few of issues regarding exported data from ArchiCAD:

Exporting Curtain Walls with the setting "Keep hierarchy"
1. As long as we stick to the classic curtain wall the default IfcPlate + IfcMemeber structure all is well.
4. Movable elements inside Curtain Walls we'd like to classify as IfcDoor or IfcWindow. These Elements exported as part of a Curtain Wall will not have BaseQuantities.
6. We also tend to model certain types of suspended ceilings with the Curtain Wall tool. In which case we would set both the main element and the subelements to IfcCovering CEILING. Resulting again in the subelements being exported without any BaseQuantities at all.
Exporting IfcRailing modelled with the Wall tool also results in lack of BaseQuantities.

We are currently implementing a workaround that includes some special ArchiCAD classifications for the aforementioned elements that will result in different IfcTypes when exported for model coordination and for the sustainability workflow but it's not ideal. (E.g.: the IfcWindows inside the facade will be IfcPlates when exported for our LCA software).

Operating system used: Windows 11

topic Problems with Base Quantities in several cases in Project data & BIM

Problems with Base Quantities in several cases