topic PBC between columns and wall - how to control the surface of the removed part in Modeling

PBC between columns and wall - how to control the surface of the removed part

alemanda — Mon, 16 Mar 2026 10:37:21 GMT

Hello everyone.

I have an issue.

I'm in archicad 27.

I have two thin columns that I want to use to have a groove in the wall.

The two columns have a building material with 900 priority. The wall has a building material with a lower priority.

The wall and the columns are on different layer with the same intersection number, so PBC is active.

When I switch off the layer of the columns I see correctly the missing volume of those columns but the surface of this part of wall is not under my control. I don't understand the reason of the used surface for the missing volume faces.

I prefer using PBC becasue is practical in the workflow compared to boolean operations.

On the other hand with SEO I can control the surface.

Any help is appreciated. Thanks

Operating system used: Windows last hotfix

Re: PBC between columns and wall - how to control the surface of the removed part

CosminF — Mon, 16 Mar 2026 10:46:16 GMT

Hi,

The surface of the "cut" is the building material of the wall. I replicated your situation and I can see the inner grooves changing based on the building material of the wall:

And it works with composites too.

Re: PBC between columns and wall - how to control the surface of the removed part

alemanda — Mon, 16 Mar 2026 11:43:00 GMT

Thanks!

I did some similar attempts but probably I was under graphic override and I didn't notice what you mentioned. You're right!

Thank you very much