Not a 'type of condo' idea but a sugestion on building your own. At present walls are fixed size objects which you bolt together. How about having a single 'wall' object that can be stretched to any reasonable size? This could have a texture selector attached to it so it could be made out of any material (that's on the servers).
It could be rotated about any axis to make a floor, roof, etc.
Window frames , door frames etc would consist of 2 parts. A hole and a model. The hole would punch through walls to allow players to pass through, look through etc. Windows/doors etc would fit into these and have open and closed states with an anim in between.
This way the devs only have to design the mechanincs of a single 'wall' & add a bunch of textures rather than model multiple types of wall.