(a) “Multiple dwelling” means a building containing the following:
(1) Three (3) or more dwelling units; or
(2) Two (2) or more dwelling units above the first or ground floor; or
(3) One (1) or more dwelling units if the building also contains a use other than a dwelling use or an area designed for such other use.
(b) The words “multiple dwelling” and “apartment house” are synonymous.