The City Planning Commission may grant a special permit for 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 and that no roof parking is permitted. The Commission 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 set forth in Section 12-10 (DEFINITIONS). As a condition of permitting such use, the Commission shall make the following findings:
(a) such use is so located as to draw a minimum of vehicular traffic to and through local streets in nearby residential areas;
(b) 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; and
(c) 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.