Every one-story dwelling hereafter erected in any R-2 one-family district shall have a total ground floor area of not less than one thousand four hundred (1,400) 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-2 one-family dwelling district shall have a total floor area, measured from the outside of the exterior walls, of not less than one thousand eight hundred (1,800) 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 area. (Ord. 1445 § 4 (part), 1996; prior code § 40-6-2(F))