Every one-story dwelling hereafter erected in any R-3 one-family dwelling district shall have a total ground area of not less than one thousand two hundred (1,200) square feet, measured from the outside of the exterior walls, including utility rooms, but excluding cellars, basements, open porches, breezeways and garages. Every dwelling of more than one story hereafter erected in any R-3 one-family dwelling district shall have a total floor area, measured from the outside of the exterior walls, of not less than one thousand six hundred (1,600) square feet, including utility rooms, but excluding cellars, basements, open porches, breezeways and garages, except that enclosed space intended for habitable rooms which are to be completed within a reasonable time may be considered in computing such floor areas. (Ord. 1445 § 4 (part), 1996; prior code § 40-6-3(F))