We can snap to IFC link elements to create new elements and we can also dimension to elements in the link. We can also Align Revit elements to IFC-based elements as well as Host some face-based families, such as electrical devices. Dimensions will only recognize the faces of linked IFC geometry and not any center lines, reference planes, or other non-geometry elements.
This is a plan view of linked IFC walls and doors along with a few local walls and doors. Rooms were added to the overall plan, using the room bounding setting for the linked IFC file.
If the IFC file changes and it is reloaded into the Revit model, previously established references may not be maintained. We’ll have to make sure they are intact. It is difficult to ensure that changes to IFC geometry will retain relationships between any dimensions that reference it.