Section 27-2058. Lighting and ventilation of living rooms in multiple dwellings erected after nineteen hundred twenty-nine

a.  Required  windows.  Every  living  room in a multiple dwelling erected after April
  eighteenth, nineteen hundred twenty-nine, shall have at least one window
  opening on:
    (1) a street;
    (2) a lawful yard or court on the same lot;
    (3) a partially enclosed balcony or space above a setback which  opens
  directly  to  a  street,  yard or court if the area of the front of such
  balcony or space open to the outer air is at least equal to seventy-five
  percent of the floor area of such balcony or space; or
    (4) A completely enclosed balcony  or  space  above  a  setback  in  a
  fireproof multiple dwelling if: the enclosure is not more than one story
  in  height;  the  outer  enclosing  walls  and roof are of incombustible
  materials; an area, glazed with clear plate glass or plastic equivalent,
  on the outer enclosing walls if at least fifty percent of  the  area  of
  the  interior enclosing walls; and at least fifty percent of such glazed
  area opens on a street, legal yard or court.  One-half  of  such  glazed
  area  shall  be openable. A living room does not include a kitchen under
  this paragraph.
    b. No required window of a living room shall open on an  offset  or  a
  recess of less than six feet in width.
    c.  Size  of  windows.  (1)  The total area of all windows in the room
  shall be at least one-tenth the floor area of  such  room,  except  that
  when a room opens solely on a balcony or space above a setback the total
  area  of  such opening shall be one-tenth the combined floor area of the
  room and that portion of the balcony or space directly in front of  such
  room.    In determining the ratio of windows to floor area, the combined
  glazed area of windows and doors opening on a balcony or a space above a
  setback may be used.
    (2) Every required window shall be at least twelve square feet.
    (3) At least one-half of every required window shall open, except that
  for a mullioned casement window a minimum of five  and  one-half  square
  feet is sufficient. In a room where a centralized mechanical ventilating
  system  provides forty cubic feet of air per minute, twenty-five percent
  of the window area or five  and  one-half  square  feet  of  such  area,
  whichever is greater, shall be openable.
    (4)  The  top  of  one required window in every room shall be at least
  seven feet above the floor, except that in dwellings erected pursuant to
  plans filed after April twenty-third, nineteen hundred  fifty-nine,  and
  prior to June fourteenth, nineteen hundred sixty-seven, this requirement
  shall not apply.
    d.  Through  ventilation. (1) No part of any living room with windows,
  or doors in lieu thereof, opening on a balcony or space above a  setback
  shall  be  more  than  thirty  feet  from the exterior face of the outer
  enclosing wall.
    (2) In any dwelling unit in a non-fireproof multiple dwelling or in  a
  dwelling  unit  of three rooms or less in a fireproof multiple dwelling,
  no part of any room shall be more than thirty feet from a window opening
  on a street or yard unless such room also opens on a legal court.
    e. Openings on lot line. Every window  and  its  assembly  in  a  wall
  situated  on  a  lot line, except a street line, shall be fireproof; the
  assembly shall have a fire resistive rating of at  least  three-quarters
  of  an  hour;  and  the  window shall be glazed with wire glass at least
  one-quarter of an inch thick. Every such window shall  be  of  automatic
  self-closing  construction whenever it is less than fifty feet above the
  non-fireproof roof of another structure located thirty feet or less from
  the lot line.

    f. Dining space. A dining space shall have a window which:
    (1) Complies with the provisions of subdivision a of this section, and
    (2)  Has  an  area  at  least one-eighth the floor area of such dining
  space.