N.Y.C. Admin. Code § 27-462: § 27-462 Construction.

All materials used in the construction of open parking structures shall be noncombustible. Columns in parking areas shall comply with the provisions of section 27-559 of article three of subchapter nine of this chapter. Interior finishes shall be class A. The minimum clear height of any parking tier shall be at least six feet six inches.

(a) Below grade. Any portion of an open parking structure extending below grade shall comply with all of the requirements for public garages as provided in article ten of this subchapter.