Buildings, for the purpose of this chapter,
shall be classified in respect to their occupancies as follows:
A. One- and two-family dwellings: buildings containing
one or two dwelling units with not more than one family in either
one of such dwelling units.
B. Multiple dwellings:
(1) Buildings containing three or more dwelling units.
In dwelling units, the maximum number of occupants
shall be limited to the number determined on the basis of the floor
areas of habitable rooms, other than kitchens, as follows:
A. One occupant per room having a floor area of at least
90 but less than 140 square feet.
B. Two occupants per room having a floor area of at least
140 but less than 200 square feet.
C. Three occupants per room having a floor area of 200
or more square feet.