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This is the first time I write in this forum, so first of all, thank you all for reading this. I hope I can also contribute in the future.

I haven’t found a topic regarding the purpose of “IfcBeamTypeEnum”, but if there is any, I apologise.

My structural software classifies the concrete joist that forms part of a slab as IfcBeam, as well as the wood joists. As I see in the following link, we could add the value of IfcBeamTypeEnum:
Concrete joist : IfcBeamTypeEnum = T_BEAM.
Wood joist: IfcBeamTypeEnum = JOIST

I have seen that this information is optional, but what’s the purpose of adding it? I’m asking because I could add it in Archicad, if there is any benefit.


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Hi Goba,

i was just about to write about this topic when by accident I say your message.

I am also facing the same problem (also working in Archicad). I find the definition of IfcBeamType helpful since, the user is able to correctly specify the type of the beam used.

One thing I don’t understand in the IFC Structure:

When comparing IfcCovering with IfcBeam, which both have a TypeEnumeration, you don’t see the Attribute inheritance for the IfcBeam, whereas for IfcCovering it is set as Optional. I am talking here about IFC2x3. In the IFC4ADD1 both of them have the PredefinedType in the list, but this also does not work in the BIM-Authoring tool for the IfcBeam.

So my question so far is: why is there no Attribute inheritance for IfcBeamTypeEnum in the IfcBeam for IFC2x3?

So my conclusion so far is, we are implemeting IFC2x3 where this option has been maybe not included and the software vendors have implemented it as the list shows.

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In IFC2x3 many definitions were not complete - hence the continuous work to publish IFC4 and successors. Among those improvements in IFC4 there was a lot of rationalization, e.g.:

  • for each occurrence object underneath IfcElement, there is now also a type object (before, some, like IfcPileType where missing
  • all leave node subtype type of IfcElement, now have a predefinedType.
  • (since Add2) all direct attributes on IfcElement subtypes, like at reinforcing elements, are now deprecated and psets should be used consistently

there should be less exceptions, etc.



Thanks a lot! All this is beyond my knowledge! I am just starting with IFC. I’ll keep reading and learning :blush:

I have checked an IFC4 generated by my structural software, and it includes the definition of PredefinedType for IfcBeams (this was not in 2x3 version).


thanx @TLiebich for the explanations. About which IFC4 exactly are we talking about?
In IFC4 the structure has been already defined where the TypeEnum for Beam is already described. Is the software no certified yet to handly this matter?

@GOBA since you previously mentioned Archicad, did you really manage to export an IFC Model with the PredefiniedType for the Beam???


@agron, I’m sorry for the misunderstanding. I was assuming that it was possible to export it from Archicad, but I haven’t tried, so I don’t really know if it’s possible.


I opened sourced a utility to generate an ARCHICAD xml for classification from the IFC toolkit currently embedded into IfcDOC.
You can find the resulting xml file as part of that repository (link below).

Let me know if it’s helpful, I’m not an ARCHICAD expert.