Revit opens Industry Foundation Classes (IFC) based on the latest International Alliance for Interoperability (IAI) IFC 2x3 data exchange standard. (If you open a file that uses an earlier standard [IFC 2x or 2x2], Revit supports the format and opens it properly.)
When you open an IFC file, Revit creates a new file based on the default template. For information about selecting the default template, see Selecting a Template for IFC Files.
You can load your own IFC class mapping files and override the categories and subcategories for IFC objects.
To open an IFC file
Revit creates a new file based on the default template.
To add IFC data to an existing project