Suburban residence districts, hereinafter designated as R-S districts, are established to regulate and control the development in appropriate areas of relatively large building sites at various densities in harmony with the character of existing or proposed development in the neighborhood, and to assure the provision of light, air and privacy, and the maintenance of usable open space in amounts appropriate to the specific types and numbers of dwellings permitted. Adherence to a specified site development review plan is required for the disposition of buildings, the relationship between living areas and those needed for vehicular access, circulation and parking in order to assure the optimum utilization of the building site. (Prior gen. code § 8-28.0)