2006 New York Code - Separation And Ventilation Of Stairs.

 
    §  205.  Separation  and  ventilation  of  stairs.  1.  All stairs and
  fire-stairs shall be completely separated  from  one  another  and  from
  every  elevator  or  other  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 and fire-stairs 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 one-quarter inch thick and at least
  three hundred sixty square inches in area.
    3.  At  the highest level of every stair and fire-stair there shall be
  provided a window or a skylight. At such termination, there  shall  also
  be  an  opening  of  at least one hundred forty-four square inches which
  shall communicate directly to the outer air, which opening may be a part
  of such window or skylight. Except as  herein  provided,  such  skylight
  shall  ccomply  with  the  provisions  of subdivision two of section one
  hundred eight.