New York Consolidated Laws, Multiple Dwelling Law - MDW § 193. Frame buildings

No frame building shall be erected or maintained upon the same lot with a dwelling converted after April twenty-eighth, nineteen hundred thirty, nor shall any frame building not occupied on April thirteenth, nineteen hundred forty, as a multiple dwelling be altered or converted to such use;  except that if the walls of a frame converted dwelling are faced with a veneer of brick and the entrance story is occupied by not more than one family, such entrance story may be altered so that it may be occupied by two families.