How to set level of newly placed FamilyInstance?

Question

I'm placing a new face-based family instance into my Revit model with the help of the NewFamilyInstance Method (Face, XYZ, XYZ, FamilySymbol) method described here. This works fine, except the instance does not have its level set to that of the host (it's set to -1 when accessed through the API and just left blank in the UI).

I tried setting the level like such

placedInstance.LevelId = hostWall.LevelId

and following this approach also tried

placedInstance.get_Parameter(BuiltInParameter.FAMILY_LEVEL_PARAM).Set(hostWall.LevelId);

but both throw an error saying the parameter is readonly.

Any help would be appreciated!

Jeremy Tammik · Answer

On some elements, the element level can only be set during the creation of the element. For that, I would assume that you need to use a different overload of the NewFamilyInstance method. Please refer to this explanation by The Building Coder and a few recent discussions of related topics in the Revit API discussion forum:

How to set level of newly placed FamilyInstance?

1 Answers