Section 192. Cellar entrance

a. If there is a cellar, there shall be an
  independent entrance thereto from outside the dwelling  by  means  of  a
  metal  fire  ladder  or  fireproof  stair  leading  to an opening in the
  outside cellar wall at least two feet six inches in width and  six  feet
  in  height.  Such  entrance  to  the cellar may be through an areaway or
  through a fireproof passageway  leading  directly  to  the  street.  The
  entrance  to  the cellar may be closed off with a grating or doors which
  shall not be locked or bolted unless they can  be  readily  unbolted  or
  unlocked  from  the  inside  without  a  key  and  shall be arranged and
  constructed so as to be readily opened at all times.
    b. In lieu of the requirements set  forth  in  subdivision  a  hereof,
  buildings existing November first, nineteen hundred forty-nine in cities
  having  a  population  between five hundred thousand and one million may
  comply with the following:
    1. shall have an unobstructed entrance through a yard or court from  a
  street:
    (a)  directly  to exterior dwelling entrance with interior entrance to
  basement or cellar direct from said entrance, or from  a  fire  retarded
  public hall or stair landing, and
    (b)  to  one  or  more  cellar or basement walls containing accessible
  windows.
    2. The stairway leading to cellar or basement shall be  enclosed  with
  fire  retarded partitions or equal construction and shall have a minimum
  fire rating of one hour. Said  cellar  or  basement  entrance  shall  be
  equipped with a one hour self-closing fire door assembly.