Standard and User Defined Property Sets

It is possible to attach standard or other custom property sets to IFC instances, for example

This example uses several expression types, and the units of the expression result are applied to the Ifc property value. In addition, the @@IFCPOSITIVERATIOMEASURE in the Desc column in an example of an explicit type-override to control

If the expression returns a list of values, then an IfcPropertyListValue will be exported, otherwise an IfcPropertySingleValue.