In C5-3, C5-5 and C6-9 Districts, the residential floor area ratio of a zoning lot may be increased to 12.0, provided that recreation space, for the residential occupants of the building on such zoning lot, is provided in an amount not less than 16.25 square feet for each dwelling unit or a total area of at least 5,000 square feet, whichever is greater.

Such recreation space may be located at any level, including a roof, and shall:

(a)        be restricted to residential occupants of the building and their guests for whom no admission or membership fees may be charged;

(b)        be directly accessible from a lobby or other public area served by the residential elevators;

(c)        be landscaped, including trees or shrubbery, except where covered or developed with recreational facilities and seating areas;

(d)        contain not less than 500 square feet of continuous area on a single level with no dimension of less than 15 feet; and

(e)        have not less than 50 percent of the area open from its lowest level to the sky. The remaining portion may be roofed and up to 50 percent of its perimeter may be enclosed. In no event may more than 25 percent of the required recreation space be fully enclosed. All enclosures shall be transparent except when located within the building. Covered areas shall contain recreation facilities or seating areas.

A copy of requirements (a) through (e) shall be permanently posted in a conspicuous place within each recreation space.