4.4.11 How to use IFC properties and attributes

IFC properties and attributes can be used in exactly the same way as ARCHICAD properties (see section 4.4.7, How to use properties). IFC property sets are referenced just like ARCHICAD property groups, and prefixing the set name to the IFC property name is also optional (if you are confident the property name is unique). IFC attributes are not arranged in sets and should be referenced by name alone. Examples follow below:

IFC property with set	element.ifcProperty("Pset_QuantityTakeOff::Reference")
IFC property	element.ifcProperty("Reference")
IFC attribute	element.ifcAttribute("Description")

The resulting value is void if the element doesn’t have an IFC property/attribute with the requested name – this does not cause errors and any calculations using that value will yield a result of zero. Quantities is highly tolerant of property value type differences, as noted in section 4.4.2, Does the data type matter?. Units are defined by the IFC documentation and calculations using them may need to incorporate a conversion factor.