In C1-1, C1-2, C1-3 or C1-4 Districts, the City Planning Commission may permit public parking garages or public parking lots with a capacity of not more than 100 spaces, provided that the regulations set forth in Sections 36-53 (Width of Curb Cuts and Location of Access to the Street), 36-55 (Surfacing) and 36-56 (Screening) are met. The Commission may permit some of such spaces to be located on the roof of such public parking garage, or may permit floor space on one or more stories and up to a height of 23 feet above curb level, to be exempted from the definition of floor area as set forth in Section 12-10 (DEFINITIONS). As a condition of permitting such use, the Commission shall make the following findings:

(a)        that such use is so located as to draw a minimum of vehicular traffic to and through local streets in nearby residential areas;

(b)        that such use has adequate reservoir space at the vehicular entrance to accommodate a minimum of 10 automobiles or 20 percent of the spaces so provided, whichever amount is less;

(c)        that, where roof parking is permitted, such roof parking is so located as not to impair the essential character or future use or development of adjacent areas; and

(d)        that, where any floor space is exempted from the definition of floor area, such additional floor space is needed in order to prevent excessive on-street parking demand and relieve traffic congestion.

The Commission may prescribe appropriate conditions and safeguards to minimize adverse effects on the character of the surrounding area, including limitations on signs or requirements for the shielding of floodlights or for setback of any roof parking area from lot lines.