“Building area” means the maximum horizontal projected area of the principal and accessory building, excluding open steps, terraces, unenclosed porches of one story, and architectural appurtenances projecting not more than two feet. Building area, as that portion of a lot upon which construction is permitted, is as follows: That area of a lot that lies within the boundaries of the front, side and rear yard setback requirements measured from the actual lot line.
(Ord. 1178 § 3.1 (part), 1987)