Hey, I tried setting this up ages ago and it didn't work. I'v just seen your post and this is exactly what I'm trying to do.. I wonder if you can clarify your settings a bit more because I get no value.
When I go into the roof properties my Pitch reference is grayed out and wont show as an option in the label.
I'm using AC20 so there shouldn't be much difference. I'm wondering If I have the property type or value type incorrect.
My options are -
IfcSlab
Property Set name: Pset_Draughting
Property Name: Pitch
Property Type: Single Value
Value Type: IfcLabel
Rule > Roof > Pitch
Thanks.