New York Consolidated Laws, Multiple Dwelling Law - MDW § 104. Bulkheads

1. Every stair, fire-stair and fire-tower required by this chapter to extend to the level of the roof or to any terrace formed by a setback shall extend to and through a fireproof bulkhead or other fireproof enclosure in such roof or terrace approved by the department.  Such bulkhead or enclosure shall give unobstructed access at all times to such roof or terrace by means of a fireproof door and door assembly with the door self-closing.  Such a door shall never be self-locking and shall be fastened on the inside by movable bolts, hooks or a lock which does not require a key to open from the inside of the dwelling.  Stairs to a bulkhead or enclosure shall have a handrail.  When a dwelling has a pitched or sloping roof with a pitch or slope of more than fifteen degrees, no bulkhead or stair leading thereto shall be required.

2. The roof of any penthouse may for the purpose of this section be deemed part of the main roof if unobstructed access be provided and maintained between all required fire-stair landings on the main roof adjoining such penthouse, on the roof of such penthouse and on the roof of any other penthouse extending above such main roof.  Such unobstructed access, where horizontal, shall be by means of a passage at least three feet in clear width.  It may include one or more stairs necessary to provide access from any penthouse roof to any main roof adjoining such penthouse.  Such stairs shall conform to all the requirements of section fifty-three for stairways of fire-escapes.  There shall be a passageway at least four feet in clear width between such stairs and the parapet wall or guard railing of the main roof.