The overall population density shall not exceed an average gross density of four and five-tenths dwelling units per acre, further providing that the net residential density or any controlled density may be established in accordance with the comprehensive plan in three density ranges herein specified as: areas of low density which shall not exceed four dwelling units per acre, areas of middle density of not more than 15 dwelling units per acre which may be in the form of garden apartments or similar clustered dwelling units sharing common services, a maximum high density development of not more than 18 dwelling units per acre for elevator-serviced structures.

Minimum floor areas per family dwelling unit shall not apply, but shall be consistent with purposes set forth in this chapter.