1145.06 DWELLING UNIT AREA REQUIREMENTS.
   In order to promote healthful living conditions, and to preserve the value and character of residential neighborhoods, dwellings shall be erected, altered, moved, maintained, modernized, or used only in accordance with the following standards:
(a)   Area of Dwelling Unit. The sum of the gross floor areas above the basement level, including those rooms and closets having a minimum ceiling height of 7 feet, and having the natural light and ventilation as required by the building code; rooms above the first floor may be included which are directly connected by a permanent stairs and hall, and spaces under pitched roofs having a minimum knee-wall height of 4 feet if 2/3 of the room area has a minimum ceiling height of 7 feet. The area shall be measured from the interior face of the enclosure walls at the first floor line, and the interior face of the walls of those rooms which may be included under a pitched roof for one-family dwellings, and measured from the center line of party walls where applicable for two-family or multifamily dwellings. There shall be excluded all areas within garages and porches for all dwellings; utility and general storage rooms in basementless dwellings; and public halls, and utility and general storage rooms in multifamily dwellings.
(b)   Minimum Area. The minimum area of a dwelling unit, as defined in this section, shall be not less than set forth in the following schedule:
 
Dwelling
Type
District
Minimum Area
Per Dwelling
Unit (sq. ft.)
1-family
RS
R1-75
R1-60
900
1-family
R1-50
700
1-family
R1-40
575
1-family
2-family
R2F
550
450
1-family
2-family
Multifamily
 
RMF
550
450
400
 
(c)   Utility and General Storage Area. In addition to the above minimum area requirements, at least 100 square feet of utility and general storage space shall be provided in a room or rooms having a minimum 7 feet ceiling height, if similar space is not provided in a basement of each one-family dwelling, and at least 75 square feet of the space shall be provided for each two-family and multifamily dwelling unit.
      (1980 Code 151.27)