OptionalboundariesOptionalDescriptionOptionalGlobalExplicit GlobalId (22-char IFC GUID); generated when omitted.
OptionalgrossGross (centreline) floor area in m² for the GrossFloorArea quantity + GrossVolume; defaults to the OuterCurve area when omitted.
OptionalLongOptionalNameOptionalnetNet (inner-face) floor area in m²; defaults to the OuterCurve area.
OptionalObjectOptionalPredefinedSlot 9 enum (without dots). IFC4 IfcSpaceTypeEnum (e.g. INTERNAL/EXTERNAL/USERDEFINED/NOTDEFINED), or the IFC2X3 IfcInternalOrExternalEnum. Defaults to INTERNAL.
OptionalProfile
Bounding elements → one IfcRelSpaceBoundary each.