Section 207. Public halls

1. Every public vestibule or other public hall
  shall comply either  with  the  applicable  provisions  of  section  two
  hundred  fifty-eight  for  non-fireproof  dwellings,  or with all of the
  following provisions:
    a. Every such public vestibule or hall shall be  everywhere  at  least
  three  feet  eight inches in clear width and shall be separated from all
  other parts of the dwelling by fireproof floors and walls.
    b. All openings from such  a  public  vestibule  or  hall  to  stairs,
  fire-stairs,   shafts,  apartments  or  suites  shall  be  protected  by
  fire-proof doors and assemblies, with  the  doors  self-closing,  except
  that  such doors and assemblies shall not be required in any transiently
  or temporarily occupied fireproof dwelling for any apartment  consisting
  of one room opening directly upon a public hall.
    c.  Such  a  public  vestibule or hall shall not be required to have a
  window, but if it does not have a window opening to  the  outer  air  it
  shall be equipped for artificial lighting and ventilation.
    d.  Any  part of a public hall that is shut off from any other part of
  such hall by a door or doors shall be deemed a separate hall.