You can do it two ways. You could not use families as families are only needed for when you're applying something to all of the buildings. So when you select building C from the menu, you just create building C, no need for families.
Or you can use family instance variables. You have a family of buildings, bldA, bldB, bldC. If you go to the menu and select bldC, it creates a building, and sets family instance variable type to C and elsewhere you have logic that links C to the animation, properties of bldC.