topic Re: Zone boundary excludes curtainwall footprint area. in Project data & BIM

Zone boundary excludes curtainwall footprint area.

kmitotk — Sat, 22 Aug 2026 05:59:26 GMT

Normally not an issue when curtainwall is used at exterior walls but it is when used at interior room boundary walls. The curtainwall footprint areas get excluded from the zone boundary/area. The excluded footprint seems to be fixed to the curtainwall's default size and offset location; it won't update when you change the offset distance or the frame sizes. Is there a way to include this ignored footprint area?

Curtainwall could be used for many things, like custom design screen walls, etc. but it's a big problem if the floor area calc will have to end up being wrong.

Re: Zone boundary excludes curtainwall footprint area.

Barry Kelly — Sun, 23 Aug 2026 01:57:37 GMT

Like regular walls, you can adjust the relationship of curtain walls with the zones.

https://help.graphisoft.com/AC/29/INT/index.htm?rhcsh=1&rhnewwnd=0&rhmapid=#t=_AC29_Help%2F040_ElementsVB%2F040_ElementsVB-146.htm%23XREF_64220_Relation_to_Zones&rhsearch=curtain%20wall&rhsyns=%20

Barry.

Re: Zone boundary excludes curtainwall footprint area.

kmitotk — Sun, 23 Aug 2026 04:20:16 GMT

Thanks for your response Barry,

Have you tried yourself? That relation to zone setting doesn't matter. That's for the curtainwall to be either used as zone boundary or not and how it's included in the area calc. You set the curtainwall as zone boundary but the boundary itself is excluding the cw footprint area and there seems no way to extend the boundary to include the missing area.

Set the CW as boundary, zone construction method to be reference line based and set the zone polygon as Gross, and see what happens.

Re: Zone boundary excludes curtainwall footprint area.

Barry Kelly — Sun, 23 Aug 2026 09:03:18 GMT

I don't have Archicad with me at the moment.

I got the impression you just didn't want the curtain wall area to be deducted from the zone?

I see also in the help you must update the zones after changing the settings.

Barry.

Re: Zone boundary excludes curtainwall footprint area.

kmitotk — Sun, 23 Aug 2026 09:36:42 GMT

yes, updated zones with no luck.

Re: Zone boundary excludes curtainwall footprint area.

kmitotk — Mon, 24 Aug 2026 23:52:58 GMT

I don't think this is a matter of if I want, it's rather a bug. It should work exactly like regular walls, as you stated.

I hope GS will address the issue. I'd appreciate if you could report them as a moderator.

Re: Zone boundary excludes curtainwall footprint area.

Barry Kelly — Tue, 25 Aug 2026 00:43:34 GMT

I don't think there is a bug to report.

Even if there was, you need to report it so that any follow up goes through you.

I have no real idea what you are trying to achieve.

I rarely use curtain walls or zones, but I have just experimented.

The curtain wall is set as a zone boundary so you maintain the two separate areas.

(you could also place a line to act as a zone boundary and set the curtain wall to not have any affect on the zone).

I found if I adjust the nominal thickness of the curtain wall and then update the zones, it has an effect on the zone areas.

Zero nominal thickness seems to be allowed.

As I said I rarely use curtain wall, so unsure what affect this has on them - they seem to be the same in 3D.

Barry.

Re: Zone boundary excludes curtainwall footprint area.

kmitotk — Tue, 25 Aug 2026 02:34:36 GMT

Oh great, so there is a way to control the space that get missed out from the zone area. Thanks for looking into it.

I tried it myself and set the Nominal Thickness to 0. It actually still leaves 1mm gap. It never get to 0. You can see the gap if you zoom into the curtainwall while both zones being selected. That's probably the reason why your 01 and 02 zones display slightly different sq m. So 0 is a misrepresented parameter value in the curtainwall settings.

1mm might be negligible for many but I'm not that comfortable as the building code and the plan examiners in our region are very particular about the floor area calcs. They check the numbers to the millimeters. But nonetheless, this is much better than having to deal with 150mm gap.

Using a line element as a zone border is a legitimate option but it's a workaround. Curtainwall should really work exactly like a wall as a zone border without creating any gap space. I too don't use curtainwalls that often especially for the interior space but this must be an oversight, if not a bug.

As for the bug reports, I thought I saw a post from another moderator that said he'd report GS if he found any bug post in this forum, isn't that the case? If not then how would we report bugs, in the wish list page? The local rep route is just cumbersome and maybe there should be a bug report page if there isn't one already.

Kei Mito

Re: Zone boundary excludes curtainwall footprint area.

Barry Kelly — Tue, 25 Aug 2026 03:27:48 GMT

Yes there does seem to be a minimum 1mm gap, even though it say zero.

Interestingly you can type 0.1 for the gap and it will reduce, and the area will be more accurate.

If you have your 'Working Drawing' accuracy set to one decimal place, you will see "0.1" otherwise you will only se "0" even though you type 0.1 and it uses 0.1

Typing 0.01 seems to force the boundary to be ignored and the two zones will show the combined area for both.

So don't do that.

So you can get a little more accurate.

Reporting bugs, the moderators can do this but we do it the same as you would by e-mailing support.

We then get the follow up requests for more information as we are the one reporting it.

It really is best if the user reports the bug themselves so they can explain exactly the problem and provide follow up information.

It is also extra work for us, and we are just volunteers here and not Graphisoft employees.

You can report issues to your local support if you have that.

Or go to support.graphisoft.com, sign in and submit a ticket.

Barry.