Export 1st Level Space Boundaries to IFC (instead of 2nd Level)

[Anonymous]

Dear Community,
i would like to export the 1st order space boundaries for my ArchiCAD-zones into an IFC file. The problem is, that automatically 2nd Level space boundaries are exported, according to the user guide (https://helpcenter.graphisoft.com/user-guide/77331/). If i untick the box "IFC Space Boundaries" in the data conversion section of the translator, no space boundaries at all are exported.
Does anybody know a solution?
Thank you!
Kind Regards
Lothar

[Christophe Fortineau]

Hello LKBCK,

Can you explain what do you mean by "the 1st order space boundaries" ?

[Anonymous]

Hi Christophe,

i wanted to post a screenshot, but was not able to do so.

In thermal simulations, the room bounding surfaces are divided according to the question "where will be a homogenous transmissive heat flow?". So if you have one long room-bounding wall with a sauna and a coldroom on the other side, the 2nd order space boundary divides the surfaces of the long wall for every adjacent room with different thermal conditions. The 1st order space boundary would not care, it is architectural (e.g. for a quantity takeoff for finishings).

The figures in this paper might explain it quicker: https://www.semanticscholar.org/paper/Space-Boundary-Requirements-for-Modeling-of-for-and-Bazjanac/4...

Thanks
Regards
Lothar

[Christophe Fortineau]

Lothar,

Thanks about these informations Lothar.
You are able to create your own archicad properties and export them into your ifc space very easily but you have to find which ifc property does it means.

[Anonymous]

Christophe wrote:
Lothar,

Thanks about these informations Lothar.
You are able to create your own archicad properties and export them into your ifc space very easily but you have to find which ifc property does it means.

Thank you very much... Though I am afraid the space boundaries are not exportable like a semantical property. I think geometrical features follow another logic. In former ArchiCAD-versions, unselecting "export IfcRelSpaceBoundary" let ArchiCAD export 1st Level SB by default. (https://www.osti.gov/servlets/purl/1168736 , Page 17).
May you have any other idea?