topic Material (Surface) parameter to be used in expression Properties of Building Materials in Project data & BIM

Material (Surface) parameter to be used in expression Properties of Building Materials

GabrielGG — Mon, 27 Oct 2025 16:33:23 GMT

Hello,

There is an option to split the name of a building material using expression-defined properties, but the same option is not available for surfaces.

It would be helpful to create an expression property applied to building materials that splits the name of the surface.

Currently, only the surface of specific elements (wall, beam, etc.) can be used in expression properties. However, you can't use the surface itself, unlike with building materials.

Am I missing something? Alternatively, do you know of a workaround?

Thanks,

Gabriel

Operating system used: Windows 11

Re: Material (Surface) parameter to be used in expression Properties of Building Materials

Laszlo Nagy — Mon, 27 Oct 2025 16:32:56 GMT

If you go to the Building Materials Dialog and the Surfaces Dialog, you will see that the Properties functionality has been implemented for Building Materials, but not Surfaces. There have been various wishes in this area. For example, there is a wish for IDs for Surfaces, which is already Under Consideration by the Graphisoft Product Team:

https://community.graphisoft.com/t5/Wishlist/IDs-for-Surfaces/idi-p/226226

Re: Material (Surface) parameter to be used in expression Properties of Building Materials

Erwin Edel — Tue, 28 Oct 2025 08:35:06 GMT

Wouldn't the workaround for now be to have a building material specific to each surface?

Re: Material (Surface) parameter to be used in expression Properties of Building Materials

GabrielGG — Tue, 28 Oct 2025 13:21:00 GMT

Hello @Laszlo Nagy ,
In my case it's not only about an ID, it's about controlling whow the information gets exported to a BIM Model.
In our Practice we have different informations in the Name of the Surfaces (and Composites, and Building Materials) but not all of them are relevant to be exported.

Generally we use a expression Property to Split the Name of the composites ... but it's not possible to do the same with the Surface.
It's about consistency in the workflows.
We didn't had this problemm until short time ago, but the Surface information is starting to get relevant for the BIM Models in General and also for the Exchange for Quantities and Costs.

In this case would be very easy to have such an expression Property that could split the Name of the surface applied to a Building Material. We could list this in Schedules or use it for the IFC Mapping instead o the full Surface Name.

Thanks for your time
Gabriel