N.Y. Mult. Dwell. Law § 140
The provisions of this article shall apply to non-fireproof multiple dwellings erected after April eighteenth, nineteen hundred twenty-nine, and to such dwellings only. They shall apply to all such non-fireproof dwellings unless their application is expressly limited to dwellings of a particular class. They shall apply in addition to, and not in substitution for, the provisions of article three. However the provisions of this article shall not apply to a multiple dwelling three stories or less in height to be occupied by not more than three families in all, with a maximum occupancy of two families on each floor in a two story building and one family on each floor in a three story building, provided however that all the provisions of article six are complied with, including section one hundred seventy-a of said article.
N.Y. Mult. Dwell. Law § 140