Section 134. Cellar entrance

There  shall  be  a direct entrance to the
  cellar, or to the lowest story if there be no cellar, from  the  outside
  of every multiple dwelling, except that any stair leading to such cellar
  or  lowest  story  may  be  located  inside  the dwelling provided it is
  enclosed in fireproof walls and fireproof doors and assemblies, with the
  doors self-closing, at both the level of such cellar or lowest story and
  that of the story above.