Revit LT exports building elements to an IFC file based on the categories (and subcategories) to which the elements belong.
For example,
Revit LT exports a wall to the IFC entity IfcWallStandardCase, because the wall is an element from the wall category. In many cases, exporting elements from
Revit LT to IFC is straightforward and simple, and the default settings make sense.
In some cases, however, you may want to specify the IFC entity to which elements from a particular family should belong. For example, suppose you design an escalator family. It belongs to the Generic Model category, and you create for it a subcategory called Escalator. You want to ensure that when you export a project to IFC, an escalator is properly (and automatically) mapped to the class IfcTransportElement and the type IfcTransportElementType.
To map a family instance to an IFC entity
- Select the family instance in your model.
- On the Properties Palette select, "Export to IFC As" and click the dialog launcher "...".
- Optional: Use the Pulldown menu to select an IFC Schema for export.
- Optional: Use the Search field to locate the IFC entity you wish to choose.
- In the Select Export As IFC Entity dialog, specify values for Export to IFC As and IFC Predefined Type.
Note: The IFC entity selected will determine the values available for IFC Predefined Type
- Click OK.
- Use the dropdown on the Export to IFC parameter to define how the family will be exported to IFC:
- By Type - Type settings for the family will be used for IFC export. Instance values for Export to IFC As and IFC Predefined Type will be ignored.
- Yes - This instance of the family will be exported to IFC even when the type or category is disabled. Instance values for Export to IFC As and IFC Predefined Type will be used during export.
- No - This instance of the family will not be exported to IFC.
Using a similar method for exporting individual family instances to IFC entities and IFC predefined types, you may want to set up family types to export to specific IFC entities and IFC predefined types.
To map a family type to an IFC entity
- Select an instance of the in your model.
- On the Properties Palette, click Edit Type.
- In Type Properties select, "Export Type to IFC As" and click the dialog launcher "...".
- Optional: Use the Pulldown menu to select an IFC Schema for export.
- Optional: Use the Search field to locate the IFC entity you wish to choose.
- In the Select Export As IFC Entity dialog, specify values for Export to IFC As and IFC PredefinedType.
Note: The IFC entity selected will determine the values available for IFC Predefined Type
- Click OK.
- Use the dropdown on the Export Type to IFC parameter to define how the family type will be exported to IFC:
- Default - Use category mapping settings for IFC export..
- Yes - Export all instances of this type to IFC.
- No - Do not export families of this type to IFC.