That portion of the area of a lot, expressed as a percentage, occupied by all buildings or structures which include but are not limited to arcades, stairways, elevator shafts, and balconies that are roofed and that extend more than three feet above ground level. Terraces, patios, atriums, balconies, breezeways, covered patios, entryways, and any accessory structure are not included in the lot coverage.