Purpose of control. The regulatory techniques controlling the distribution of population throughout the community are intended to achieve the desired environmental character as set forth in the Comprehensive Plan and to achieve a practical economic and functional relationship between the residential use of land and its consequent impact upon traffic circulation, sewage disposal, school facilities, and other service demands.

Method of control. In single-family detached development, the density is established by the minimum required lot size. In single-family attached or multiple-family developments, no minimum lot size is established but the allowable density is established by a required ratio of lot area to each dwelling unit. In a planned residential development project, the density is established by a special factor giving the number of dwelling units permitted per acre based on the underlying zoning. In the Central City Mixed District, a maximum control may be established by the Density Factor Overlay District which provides for a sliding scale based upon the size of the parcel being developed.

How computed. The determination of the number of allowable dwelling units on a given property developed with single-family attached or multiple-family units shall be made as follows:

Minimum required. No building shall be erected, structurally altered or relocated on a lot so as to reduce the usable open area of such lot to less than that hereinafter specified by the regulations for that district.

How measured. To be considered usable, such open area shall be readily accessible and of a size and shape which can be reasonably considered to provide for the amenities and necessities of light, air, play space, drying yard, garden, etc., but shall not include parking area and drives.

Overlapping. No part of the open space provided for any building shall be included as part of the open space required for another building, except as hereinafter provided for planned development projects.