Section 144. Egress from dwellings

1. A dwelling three or more stories in
  height shall have at least two means of egress  extending  to  the  roof
  from  an  entrance  story,  street, court or yard. The entrances to such
  means of egress at every story shall be at least  fifteen  feet  distant
  from  each other unless they are on opposite sides of a public hall. One
  means of egress shall be a stair constructed as provided in section  one
  hundred  forty-eight.  The other means of egress shall be either another
  such  stair  or  a  fire-escape  constructed  as  provided  in   section
  fifty-three.
    2.  If  the  number of living rooms on any story, or in any section of
  any story, above the entrance story exceeds twenty, there  shall  be  an
  additional  stair,  or  fire-stair, extending from the entrance story to
  the roof for each twenty rooms or fraction  thereof  on  such  story  or
  section thereof in excess of twenty, except that no additional stair, or
  fire-stair,  shall  be  required for such excess on any story or section
  thereof if the number of living rooms thereon does not exceed thirty and
  if in addition one  stair  serving  such  story  or  section  and  every
  entrance  hall  or  other public hall connected therewith are everywhere
  four feet six inchs or more in clear width.
    3. There shall be accessible from every apartment two means of  egress
  from  the dwelling, one of which shall be a stair within fifty feet from
  a means of egress from such apartment. For such dwellings erected  under
  plans  filed  in  the department after September first, nineteen hundred
  fifty-one, such stair  shall  also  be  enclosed  and  comply  with  the
  provisions of section one hundred forty-eight.
    4.  Whenever  more  than  two stairs are required, one or more of such
  stairs may be fire-stairs or  fire-towers,  provided  that  there  shall
  never  be more than one such fire-stair or fire-tower for each two other
  required stairs.