N.Y. Multiple Dwelling Law § 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.