§ 190. Cellar stairs. 1. Except as provided in paragraph g of
subdivision three of section one hundred seventy-one, and except as
otherwise provided in subdivision two hereof, every stair leading from a
cellar to the floor above shall be constructed of incombustible
materials, shall have closed risers, shall be completely enclosed with
partitions of incombustible materials and shall be equipped at the
bottom with a fireproof door and assembly with the door self-closing.

2. Every existing stair leading from a cellar to the floor above in a
converted dwelling accepted or approved by the department on or before
July first, nineteen hundred sixty shall be deemed in compliance with
this section.