(a) Single-Family Residential.
(1) One Story Dwellings. A one-story dwelling shall contain not less than 900 square feet of usable ground floor area, exclusive of open porches, garages, carports or steps.
(2) One and One-Half and Two Story Dwellings. A story and one-half or a two-story dwelling, shall contain not less than 650 square feet of ground floor area, exclusive of open porches, garages, carports or steps.
(b) Apartment Units.
(1) One Story Dwellings. A one-story dwelling shall contain not less than 500 square feet of usable ground floor area, exclusive of open porches, garages, carports or steps.
(2) One and One-Half and Two Story Dwellings. A story and one-half or a two-story dwelling, shall contain not less than 500 square feet of ground floor area, exclusive of open porches, garages, carports or steps.