2006 New York Code - Separation And Ventilation Of Stairs.

 
    § 105. Separation and ventilation of stairs. 1. In a dwelling in which
  one or more passenger elevators are maintained and operated opening upon
  a  public  hall  at every story, all stairs, fire-stairs and fire-towers
  shall be completely separated from one another and from  every  elevator
  shaft  by  fireproof  walls.  They  shall  be  constructed  of fireproof
  material throughout and shall  contain  no  wood  or  other  inflammable
  material of any kind, except that handrails of hardwood may be provided.
    2.  Access  to  stairs,  fire-stairs and fire-tower balconies from any
  public vestibule or other public hall shall be through  fireproof  doors
  and  assemblies,  with  the  doors  self-closing and at least three feet
  wide, or through pairs of such doors at least four feet wide, containing
  in either case a fixed sash  glazed  with  wire  glass  at  least  three
  hundred sixty square inches in area.
    3.  Every  stair  hall  shall be ventilated by a window, or by movable
  louvres in the skylight having  an  opening  of  at  least  one  hundred
  forty-four  square  inches,  or  by  an  opening of at least one hundred
  forty-four  square  inches  near  the  top  of  the  stair   shaft   and
  communicating directly with the outer air. If a window is provided which
  does  not  open  upon a street or yard, it shall be fireproof and glazed
  with wire glass of good quality and have no pane more than three hundred
  sixty square inches in area.