2023 New York Laws › MDW - Multiple Dwelling › Article 3 - Multiple Dwellings--General Provisions › Title 1 - Light and Air › 30 - Lighting and Ventilation of Rooms.

§  30.  Lighting  and  ventilation of rooms. 1. The provisions of this
section shall apply only  to  multiple  dwellings  erected  after  April
eighteenth,  nineteen  hundred  twenty-nine, and shall apply to all such
dwellings unless otherwise expressly limited.
2.  Except  as  in  this  section  and   in   sections   thirty-three,
seventy-six,  one  hundred  fifteen,  one  hundred  sixty,  one  hundred
seventy-six, two hundred, two hundred thirteen, two  hundred  fifty  and
two   hundred   fifty-one  otherwise  expressly  provided,  every  room,
including kitchens, water-closet compartments and bathrooms, shall  have
at  least  one  window  opening  directly upon a street or upon a lawful
yard, court or space above a setback upon the same lot as that  occupied
by  the  multiple  dwelling  in  which such room is situated. Every such
window shall be so located as to light  properly  all  portions  of  the
room.
3. No room in any apartment of three rooms or less, and no room in any
non-fireproof apartment, shall extend in depth, from a street or yard on
which  it  faces,  more  than  thirty feet without a window opening on a
lawful court.
4. a. Nothing in this section or section twenty-six shall be construed
as prohibiting the windows or doors  of  any  room  from  opening  on  a
partially-enclosed  balcony  or  space  above  a  setback, provided such
balcony or space opens directly to a street or to a lawful yard or court
and the area of the front of the balcony or space which is open  to  the
outer  air  is  at  least  equal to seventy-five per centum of the floor
surface area of such balcony or space. Any living room thus lighted  and
ventilated by windows or doors opening on such balcony or space shall be
at most thirty feet in depth measured from the extreme outer face of the
wall  forming the partial enclosure of the balcony or space. The windows
or doors providing light and ventilation for a  room  or  rooms  opening
exclusively  on  such  a balcony or space shall have altogether at least
the area of one-tenth of the combined floor  surface  of  such  room  or
rooms  and the portion of the balcony or space directly adjoining and in
front of such room or rooms.
b. On a  fireproof  dwelling  a  balcony  or  space  above  a  setback
permitted  under  paragraph  a  of  this  subdivision  may be completely
enclosed, provided the outer  enclosing  wall  or  walls  and  roof  are
constructed  of  incombustible  materials  and the walls are glazed with
clear plate glass or plastic equivalent and such  glazed  wall  area  is
equal  to  at  least  fifty per centum of the area of the interior walls
enclosing such balcony or space. At least fifty per centum of the glazed
area shall be openable directly upon a street or upon a lawful  yard  or
court.  No window shall open from any bathroom, water-closet compartment
or cooking space upon such enclosed balcony.
c. The enclosure on any balcony or a space above a setback  shall  not
(1)  be  more than one story in height or (2) be erected in violation of
the provisions of paragraph a of subdivision six of section one  hundred
two of this chapter.
5.  No  multiple dwelling shall be so altered as to diminish the light
or ventilation of any room or public hall  or  stairs  in  any  way  not
approved by the department.
6.  No  window  shall  be  required  in any public room of a fireproof
multiple dwelling if such room is used solely for  storage  purposes  or
has  adequate  mechanical ventilation maintained to provide at least the
number of changes of the  air  volume  of  such  room  approved  by  the
department  as  necessary  for the health and safety of the occupants of
such dwelling. Any fresh air supply system required  by  the  department
for  such  purposes  shall  be provided with adequate means for removing

dust from the incoming air and with adequate means to heat such  air  at
least to sixty degrees Fahrenheit.
7.  No  required window shall open upon any offset or recess less than
six feet in  width  except  a  window  of  a  water-closet  compartment,
bathroom,  or  stair or of a cooking compartment less than eighty square
feet in floor surface area.
8. (a) The windows in every room, except a  water-closet  compartment,
bathroom, or cooking space less than eighty square feet in floor surface
area,  shall  have  a total area at least one-tenth of the floor surface
area of such room and every window in such a room, including a mullioned
casement window, shall be at least twelve square feet in area.
(b) All required  windows  shall  be  so  constructed  that  at  least
one-half  of  their required area may be opened, except that a mullioned
casement  window,  if  otherwise  large  enough  to  supply  the  window
requirements of the room, need be readily openable to the outer air only
to the extent of five and one-half square feet of its area.
(c)  Where  fresh  air  is  furnished in any room through a mechanical
ventilating unit or system which is an integral  part  of  the  dwelling
structure  and  capable of introducing not less than forty cubic feet of
air per minute, the required window area in such room need  be  openable
only to the extent of twenty-five per cent of such window area but in no
event less than five and one-half square feet.
9. Transoms or partition sash, or louvres having a minimum area of 144
square  inches and arranged to be opened or closed, shall be provided to
private halls  or  to  adjoining  rooms  to  secure  through-ventilation
whenever  required  by  the department, but no such transom or partition
sash or louvre shall be required in a room having two windows opening to
the outer air if each window is at least nine square feet in area, or in
a room having a mullioned or single window with an aggregate area of  at
least eighteen square feet.
10.  All windows and their assemblies in walls situated on a lot line,
except those facing on a street, shall  be  fireproof,  with  assemblies
having a fire-resistive rating of at least three-quarters of an hour and
glazed  with  wire  glass  at  least one-quarter of an inch thick. Every
opening in a wall situated on a lot line which is less than  fifty  feet
in  a vertical direction above a non-fireproof roof of another structure
within a distance of thirty feet of the wall in  which  the  opening  is
located shall be an automatic fireproof window.