IFC: IfcSpatialElement questions

  • Schematically, are you allowed to have an IfcSpatialElement be contained by another IfcSpatialElement?
  • Also schematically, are you allowed to have an IfcElement be contained by more than one IfcSpatialElement?


  • A spatial element inside another spatial element, such as a "Space" within a "Storey" within a "Building", is very common. However, confusion arises because in English we can say "contained by", but in IFC the jargon isn't correct. In IFC jargon, an element (i.e. wall) is contained in a spatial element, but a spatial element is aggregated in another spatial element. Therefore, in the BlenderBIM Add-on, you need to look at the IFC Aggregates panel.

    An IFC element may only be "contained in" a single spatial element. This primary relationship has various meanings. For example, in facility management, an element "contained in" a room means that the room is the primary means of maintenance access to that element (e.g. equipment).

    However, there is such a thing as equipment that spans multiple rooms (e.g. in ceiling voids), or between rooms (e.g. fire dampers) or multistorey columns spanning multiple storeys. For these situations, an element may be "referenced by" zero or more spatial elements. Therefore, you may have a multistorey column "contained in" the lowermost storey, but "referenced by" higher storeys.

    I haven't built support for "referenced by" yet in the BlenderBIM Add-on :)

  • Correct :)

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