2006 New York Code - Cellar And Basement Stairs.

 
    §  106. Cellar and basement stairs.  A cellar or basement stair may be
  located inside the dwelling, but shall not be located underneath a stair
  leading to the upper stories unless  it  is  a  basement  stair  leading
  upward from a basement which is the main entrance story of the dwelling,
  or  unless  it is a stair leading downward from the entrance story which
  is separated by a fireproof arch from the stair leading upward from  the
  entrance  story.    Except  as otherwise provided in subdivision five of
  section fifty-two,  all  inside  cellar  or  basement  stairs  shall  be
  entirely  enclosed  with  fireproof walls and be provided with fireproof
  doors and assemblies, with the doors self-closing, at all openings.