Read geometry in imported CAD symbol instance


I am working on an urban project and have a CAD file with footprint information for the neighboorhood (ultimately derived from GIS). The footprints are 2D polylines, with elevation as their “pad height” and thickness as their height from ground to roof. When I import or link the file into Revit, I get “3d-ish” objects - they have sidess but no roof. Exploding causes the objects to disappear. Individually, I can create mass or generic model objects for each footprint but there are hundreds of them and I’d like to do it automatically. It seems there should be a way for dynamo to query the polylines for their elevation and thickness and create objects (floors, masses, etc) to match. However, I haven’t been able to figure this out however. Anyone had a similar problem?

Thanks, N