To provide greater development flexibility, no minimum or maximum number or percentage of dwelling type (single-family detached or attached dwellings, or multiple-family dwelling) is required, since the maximum dwellings per acre will necessitate open space as a design feature within the PRD.
EXAMPLE: in a ten-acre PRD in an R-3 District, with a 15% reserve for streets and no other reductions, 85% of the land would be the "net development area," so 10 gross acres x 85% = 8.5 net developable acres x 9 units/acre = 76.5 units = 76 total units maximum dwellings.