Hello all, I recently came across a user that was wondering why we didn’t create IfcOpeningElements for IfcBeams. My first thought was “because they aren’t allowed for beams” but the schema doesn’t disallow it. I’m fairly sure that MVDs disallow it, but does anyone know if that is actually true and documented somewhere?
Hi Angel,
I think opening for beams should be allowed.
Perforated beams seems to be used quite often in user projects.
For CV 2.0 test-case Beam_02 includes perforated beams (I believe Revit passed it?)
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I would find it weird if OpeningElements/VoidingFeatures or RelVoids relationships were type constrained, they are fairly abstract and it feels right. Never seen anything like it in common mvds. 
https://standards.buildingsmart.org/MVD/RELEASE/IFC4/ADD2_TC1/RV1_2/HTML/link/ifcrelvoidselement.htm
I’m fairly sure that MVDs disallow it
@angel.velez could you point me to it?
No, I can’t point you to it, which is why I asked here 
OK, consensus seems to be that it should be OK for beams, which is what I wanted to verify, thanks!
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I agree with the consensus here. For completeness looking at IFC4 RV I can only find
On IfcElement
Elements may have voids defined, which may be partial recess or extending full depth…
On IfcReinforcingElement
The various subtypes of IfcReinforcingElement do not support the concept of voiding - there shall no voids (openings, cut-outs, recesses) being defined as shape features for reinforcing elements.
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Based on the documentation, an IfcOpeningElement can off course be inserted into a beam. Here is an extract of the documentation:
The opening element stands for opening, recess or chase, all reflecting voids. It represents a void within any element that has physical manifestation. Openings can be inserted into walls, slabs, beams, columns, or other elements.
I think it also depends on how your beam looks like. Is it a type of prefab beam that has specific requirements (respectively position and shape) of an opening? Or is it a steel beam that by standard has openings inside (such as igor.sokolov showed in his image).
In my opinion, in the first case you create opening, in the later it is already integrated in the element.