About the IFC4.3 Building Room - Building Domain Review category

This category is reserved for Review and Discussions on the implementation of the IFC4.3 Infra Extension in respect for Building Domain.
All related Domain Experts (Architecture, HVAC, Structural Engineering etc.) are kindly requested to review above mentioned IFC4.3 Schema (see https://ifc43-docs.standards.buildingsmart.org/) and provide Building Domain Steering Committee (BDSC) feedback as well as proposals for improvement (additions, corrections etc.).
We, BRSC Members, encourage you to review the schema prior start of IFC4.4. Tunnel and further Extension works. Thank you for your invaluable support!

Call for Participation on IFC4.3 Building Domain Review - Example review

Dear all,

recently a Building Room Steering Committee has held a Panel Session on IFC4.3 Building Domain Review during the bSI Virtual Autumn Summit 2021. Attached you may find a PDF copy of a presentation and a short Tipps on how to check and navigate within the IFC-Schema (based on human readable HTML) as well as recording of the session.
bSI BR4-IFC4.3 for Building Domain-Mirbek_Bekboliev.pdf (2.1 MB)
Recording → Updates to be made in Building Domain of the IFC 43 infra Extension - Mirbek Bekboliev on Vimeo

Also see BR4 Session

We kindly request all related Domain Experts (Arch / MEP / Struc etc.) to participate on review Building related Part of the IFC4.3 Schema (aka Infra Extension).

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The bS Norway Chapter have discussed the IFC4.3 Infra Extension outputs with the Technical Room in Norway and have provided the following comments and recommendations. Thanks in particular to Kjell Ivar and Alessia for making this feedback available. Please review it yourself at the following link: Box



Is there a common or crosswise vocabulary strategy when suggesting new Predefined type enumerations (i.e. ISO/DIS 6707-1)? I see the risk of increasing inconsistencies when including new options due to the previous lack of Schema definitions.

Thanks for the updates.


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Hi David,

very good point! Thank you for that.

Indeed we should take that into account. In this case all new elements should go through review anyways. IFC schema and domain experts are requested to do so.


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Here is further comment by @ElisEck PropertySets of IfcSpace

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Dear All,

attached are the further comments from Elena Chochanova (TNO). Our gratitude from BRSC to Elena for her support! Here is a Link to Download → Box

Thanks @rroef for forwarding it!

All the best


Dear All,

we have recieved further comments. This time from German buildingSMART-Working Group “BIM & Timber Construction”:

We do not want to use this one, should remain DEPRECATED. This is also the case in the IFC 4.3 proposal

This is used by us and in many IFC files we receive from other AEC programs. It should be possible to continue using this for the time being; especially since the IfcMaterialLayerSet cannot be fully used in IfcWall (see below). In the IFC 4.3 proposal, IfcWallStandardCase was set to DEPRECATED. This should not be, it should not be set to DEPRECATED.

In IfcWall you can now use IfcMaterialLayerSet, but not with IfcMaterialLayerSetUsage. How the IfcMaterialLayerSet should be aligned is not defined. Since we have needed the combination IfcWall with IfcMaterialLayerSet and IfcMaterialLayerSetUsage many times (and used it that way) this possibility would make sense. Why should it not be possible to use IfcMaterialLayerSetUsage here?

Thank you for your attention and support.

Greetings on behalf of the WG

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Where is this stated? This might be an MVD problem, not a problem with the base IFC spec.

Hi Klaus @linhard, see above a question from Dion. Could you please and clarify a response on behalf of the working group? Otherwise I will extract it send per Email. Thanks

Thanks @Moult on this topic. Anyone in Building Room would like to comment? See source Information on Swimming Pool Filters → IFC class for swimming pool filter