I've used paper on foam board for many background buildings. in the photo the tall building and the one to the right of it are both paper siding brickwork. to heighten the 3-d effect i added fire escapes, vents and roof top accessories (structure is about 1” deep). in the lower building i added tichy windows cut through the foam, roof top chimneys and an easily made basswood strip 2-window bay type extension with pipes running from the bottom and the left side. i’ve probably done about 6-8 background buildings this way each with very individual details so none look even remotely the same. pretty cost effective way to do these background structures and cover a lot of real estate.
