topic Re: Zone Tool and Suspended Ceilings (Slab Tool) in Modeling

Zone Tool and Suspended Ceilings (Slab Tool)

Heftor — Mon, 23 Feb 2026 15:38:46 GMT

Hello everyone,

I have a question regarding the Zone Tool and its interaction with ceilings, specifically those created with the Slab tool.

In my workflow, I use the Zone Tool to define rooms. I know that I can set a wall as a boundary for a zone, which works perfectly. However, I am trying to achieve a similar effect with a suspended ceiling.

The ceiling is modelled using the standard Slab Tool. My goal is for the zone to automatically detect this slab as its upper boundary, much like it detects walls as vertical boundaries. This would allow the zone to calculate its correct height (volume) based on the suspended ceiling's position.

However, it seems the Zone Tool does not currently recognize a slab as a cropping or bounding element in the same way it does walls. There doesn't appear to be a "Relation to Zones" option for slabs, which prevents the zone from automatically trimming itself to the ceiling above.

My question is:

Is there a current method to have the Zone Tool detect a slab (as a suspended ceiling) to automatically calculate the correct room height? I've looked into the Zone Settings and Project Preferences for Zones, but haven't found a solution .

I understand that the Zone top can be linked to a story and offset. Having the zone geometry respond directly to the ceiling geometry would be a major improvement.

Has anyone found a workaround for this?

Thanks for your time.

Hector

Betreff: Zone Tool and Suspended Ceilings (Slab Tool)

Stefan L_ — Mon, 23 Feb 2026 16:41:36 GMT

@Heftor schrieb:

Is there a current method to have the Zone Tool detect a slab (as a suspended ceiling) to automatically calculate the correct room height?

No. 😞

@Heftor schrieb:

Has anyone found a workaround for this?

We did this once (yet):

- IFC export

- collision control zone vs. suspended ceiling & some ITO magic

- create zone issues with ceiling height and storey

- import issues to AC

- type height into property manually

(reset and repeat) 😞

Re: Zone Tool and Suspended Ceilings (Slab Tool)

Ricardo Lopez — Thu, 26 Feb 2026 08:45:22 GMT

Hi @Heftor

Although there is no relation to zone option for slabs, you could add the slab/ceiling as an Operator and the zone as a Target in a Solid Element Operation of Subtraction with upward extrusion. This way you could get a "geometric relationship" but it doesn't affect the Height field in your schedules.

You could also try the specific properties for zones under the group SUSPENDED CEILING LEVEL. It is a manual procedure, but you can type the Sub Ceiling Thickness to get the Suspended Ceiling Level as an expression result.

Re: Zone Tool and Suspended Ceilings (Slab Tool)

marcoariveross — Mon, 23 Feb 2026 19:51:55 GMT

We use a reverse process, so to speak.
The area defines our ceilings. We use the accessories tool.

Re: Zone Tool and Suspended Ceilings (Slab Tool)

Heftor — Wed, 25 Feb 2026 11:31:27 GMT

Hi @marcoariveross , @Ricardo Lopez and @Stefan L_ ,

I was double checking in case that I have missed a setting or a procedure for this situation, because we made the rooms and now the label display the height from the stories, and not the real free room that we have after modelling the suspended ceilings.

Anyway, thanks for the answers and help 💪