Except within the Eighth Avenue Perimeter Area set forth in Section 96-22 (Special Regulations for Eighth Avenue Perimeter Area), in all other C6 Districts, the City Planning Commission, by special permit, may permit, for public parking garages, modification of the applicable lot coverage, yard and height and setback regulations. As a condition of permitting such modifications, the Commission shall make the following findings:

(a)        that, because of site limitations, such modifications are necessary for the proper design and operation of the public parking garage; and

(b)        that, such modifications will not unduly obstruct access to light and air in the street or on adjacent zoning lots.

The Commission shall consider the characteristics of surrounding development and may prescribe appropriate conditions and safeguards to minimize adverse effects on the character of adjacent areas.