2006 New York Code - Fire Escapes.

 
    §  27-380 Fire escapes. Fire escapes constructed on existing buildings
  when altered or as a second means of egress for group homes as permitted
  by section 27-368 of this article shall comply with the following:
    (a) Capacity. The capacity of fire escapes shall be as listed in table
  6-1 for stairs.
    (b)  Stairs.  The  minimum  width  of  fire  escape  stairs  shall  be
  twenty-two  inches.  Treads  shall have a minimum width of eight inches,
  exclusive of a required one inch nosing. The maximum  height  of  risers
  shall  be  eight inches. No flight of stairs shall exceed twelve feet in
  height between landings.
    (c) Landings. Landings shall be provided at each story served by  fire
  escapes.  The  minimum  width  of  landings shall be three feet, and the
  minimum length shall be four feet six inches. Floor openings in landings
  shall be at least twenty-two inches by twenty-eight inches.
    (d) Handrails  and  guards.  Handrails  having  a  minimum  height  of
  thirty-two inches above the tread nosing shall be provided on both sides
  of stairs, and guards having a minimum height of thirty-six inches shall
  be  provided  on all open sides of landings, openings in guards shall be
  of such dimensions as to prevent the passage of a five inch dia. ball.
    (e) Construction. Fire escapes shall be constructed of  noncombustible
  materials  adequately  protected  against  deterioration by corrosion or
  other effects of exposure to the  weather,  and  shall  be  designed  to
  comply with the requirements of subchapter nine of this chapter.
    (f) Access. Access to fire escapes shall be by doors or windows having
  a minimum clear opening of twenty-four inches in width and thirty inches
  in  height. Such doors or windows shall have a fire protection rating of
  three-quarters of an hour except in buildings  classified  in  occupancy
  group J-2.
    (g)  Discharge. The top landing of fire escapes shall be provided with
  a stair or gooseneck ladder  leading  to  the  roof,  except  that  this
  requirement  shall  not  apply  to buildings having a roof pitch of more
  than twenty degrees. The lowest landing of fire  escapes  shall  be  not
  more than sixteen feet above grade and shall be provided with a stair to
  grade which may be counterbalanced.