As specified in the schedule of regulations Section 37-63.

Variable Lot Size Provision. In a major subdivision application, variable lot sizes may be approved by the Planning Board. The lot sizes may be varied to the extent that the lots may have areas of not less than thirty thousand (30,000) square feet each and widths of not less than one hundred twenty-five (125) feet if a sufficient number of the remainder of the lots are increased in area so that the average lot size will be not less than forty thousand (40,000) square feet. The Planning Board, in passing on such plats, shall consider the physical and structural characteristics, including topography of the land comprised in the subdivision, and determine that such variation in lot size will provide a better layout of the subdivision and a better use of the land for building sites that would a uniform lot size. The subdivider shall submit a plat map showing the development according to the requirements of the R-AA district as shown in the schedule, Section 37-63, and another plat map showing the development as modified in accordance with this subsection. In no event shall the density of development throughout the subdivision exceed the exact number of lots that would have been permitted to be built if such development has proceeded on the basis of forty thousand (40,000) square feet per lot with a width of not less than one hundred fifty (150) feet.