New York Consolidated Laws, Multiple Residence Law - MRE § 52. Public halls and stairs

The walls and ceiling of every entrance hall, stair hall or other public hall, every hall or passage not within an apartment or suite of rooms, every dumbwaiter, elevator, and, every other shaft, including stairs, connecting more than two successive stories, shall be sealed off from every other portion of the dwelling with fire-retarded materials, or, in lieu thereof, except in the case of elevator shafts, shall be equipped with an automatic sprinkler system.  Except as provided in subdivision five of section fifty-five, nothing contained in this article shall be deemed to exempt an interior required means of egress from the enclosure requirements or the equipment provided for in this section.  A fire-detecting system shall not be acceptable for any of the requirements of this section.