The population restrictions contained in this paragraph shall not apply to any multiple dwelling otherwise entitled to the variances herein pursuant to the provisions of subdivision seven of section fifty-six of this chapter.
Variations or modifications may be granted pursuant to Paragraphs b and c only on condition that open areas for light and air are provided which are at least equivalent in area to those required by the applicable provisions of this chapter and pursuant to sub-paragraph one of paragraph c only on the further conditions that there are unique physical or topographical features, peculiar to and inherent in the particular premises, including irregularity, narrowness or shallowness of the lot size or shape and such variance would be permitted under any provision applicable thereto of the local zoning ordinance.
N.Y. Mult. Dwell. Law § 310