Section 274. Fire-escapes erected before October first, nineteen hundred and thirteen

All  outside  fire-escapes  erected  before  October  first,
  nineteen hundred and thirteen, and serving as required exits  under  the
  provisions  of  section two hundred and seventy-one shall conform to the
  following requirements:
    1. There shall be balconies on each floor of  the  building  connected
  with stairways placed at an angle of not more than sixty degrees.
    2.  A  stairway  shall  lead  from  the top floor balcony to the roof,
  except when the fire-escapes are erected on the front of the building.
    3. A stairway not less than twenty-two inches wide shall lead from the
  lowest balcony to a safe landing place  beneath,  which  stairway  shall
  remain  down  permanently  or  swing  up  and  down  by counterbalancing
  weights.
    4. A safe and unobstructed exit shall be provided to the  street  from
  the foot of such fire-escapes as required in subdivision nine of section
  two hundred and seventy-three.
    5.  Steps  shall  connect  the  sill  of  every opening leading to the
  fire-escapes with the floor wherever such sill is more than  three  feet
  above the floor level.
    6.  All  openings  leading  to the fire-escapes shall be provided with
  fireproof windows or fire doors.
    7. All windows opening upon the course of  the  fire-escape  shall  be
  fireproof windows.