Exterior, House Building Type, Flat RoofLine, Mid-Century Building Type, and Prefab Building Type The Rudin House in Madison, built following Lloyd Wright's prefabricated Plan #2 for Marshall Erdman's company, is one of two homes built as a large, flat-roofed square with a double-height living room accented with a wall of windows. [Photo via Mike Condren]  Photo 4 of 6 in A Look at Frank Lloyd Wright's Little-Known Prefabs