A 3½ story, unfinished residence has four levels, with the upper level unfinished, and is characterized by a steep roof slope (8 to 12 or greater) and dormers. Because of the roof design, the area of the fourth floor is usually 40% to 60% of the third floor area. Since the fourth floor is unfinished, enter the area for the first three floors only for total floor area. This style is available for single-family residences only.