Each apartment unit in each apartment building shall contain separate bedroom, separate bathroom, separate living room and separate kitchen facilities, which kitchen facilities shall be located separate and apart from other rooms. A bedroom shall be construed as any separate room other than a dining room, living room, kitchen or bathroom. Each garden apartment development shall have at least seventy-five (75%) percent of the dwelling units thereof as one-bedroom units and not more than twenty-five (25%) percent as two-bedroom units. Only one-bedroom and two-bedroom units shall be permitted. It shall be the obligation of the lessor to restrict all tenants to the use of the individual rooms for the designed and intended purposes. One-bedroom units shall not be less than seven hundred fifty (750) square feet of living area and the two-bedroom units shall have no less than nine hundred (900) square feet of living area.