(A) All single-family dwellings, whether attached or detached, shall have at least one story above grade.
(B) The minimum horizontal dimension of a single-family detached dwelling shall be 20 feet for at least 65% of the longer horizontal dimension of the dwelling, said dimensions to be exclusive of attached garages, porches or other accessory structures.
(C) No structure or vehicle shall be used or occupied as a dwelling unit, or otherwise inhabited, unless it has a minimum floor area of 320 square feet; is legally parked or located on a lot, manufactured dwelling park or recreational vehicle park or campground, and fully conforms to all city codes.