Multiple Dwelling Law

TITLE 1
Multiple Dwelling Law (MDL)

S 172. Yards and courts. 1. Except as provided in subdivision two,
there shall be a yard thirteen feet or more in depth across the entire
lot in the rear of every converted dwelling, or an outer court three
feet or more in width which alone or with any open space at the rear of
the dwelling equals the required area of such a yard.
2. On a corner lot there shall be a yard ten feet or more in depth
across the entire lot. Such yard shall be thirteen feet or more in depth
for any part of the yard which is more than sixty feet from any side
street bounding such lot. The provisions of this subdivision need not
apply to a dwelling situated on a corner lot if (a) the required windows
of all living rooms in such a dwelling open directly upon a street (b)
the height and bulk of the dwelling are not increased and (c) the bulk
of the dwelling above the first story is not increased.
3. The bottom of a yard may be as high as but not above the second
tier of beams, provided the first story is used exclusively for business
purposes and there is no living room in or below the first story; and
provided also that whenever any means of egress from the upper stories
opens into such yard, a portion of the yard ten feet or more in depth
and open from the ground up shall be maintained at the rear of any
extension of the dwelling.
4. In the rear of every converted dwelling on a corner lot an
extension of the dwelling over the yard may be built up to the second
tier of beams, provided such extension does not obstruct any required
means of egress from the upper stories.
5. Except as provided in subdivisions three and four, the required
yard or court and unoccupied space shall be open and unobstructed from
the ground up.
6. The restrictions of this section and those of subdivisions one and
two of section one hundred seventy-one in regard to bulk and volume
shall not apply to extensions erected before April thirteenth, nineteen
hundred forty, in conformity with the provision of a local zoning
resolution which restricted bulk and volume.
7. Nothing in this section shall be deemed to permit extensions in the
yards or courts of any converted dwelling, or to permit business or
commercial uses therein, which may be contrary to any local zoning law,
ordinance or regulation.

S 173. Windows in rooms. 1. Except as provided in subdivision four of
section one hundred seventy-seven every living room shall have one or
more windows opening directly upon a street or upon a yard or court with
dimensions conforming to those specified in section one hundred
seventy-two, or upon an inner court or shaft three feet nine inches or
more in width and eight feet or more in length.
2. Such windows shall be so located as to light properly all portions
of the room and in each room shall have an aggregate glazed area of at
least one-tenth of the floor area of the room, unless in the opinion of
the department such room is already adequately lighted and ventilated.
The top of at least one window in each living room shall be seven feet
or more above the floor except when such room is in the basement or on
the top story, in which case the top of at least one window shall be six
feet or more above the floor. Every such window shall be twelve square
feet or more in area, and shall be so constructed that one-half or more
of its area may be opened. However, such window need not be twelve
square feet in area provided that each room shall have an aggregate
glazed window area of at least one-eighth of the superficial floor area
of the room.
3. Whenever a basement conforming to the provisions of subdivision
four of section one hundred seventy-seven is permitted to be occupied
for living purposes, every living room, bathroom, water-closet
compartment, kitchen and cooking space therein shall have one or more
windows opening directly upon a street; or upon a yard which is at every
point at least fifteen feet in depth and, above the window sill level of
the first story above the basement, at least twenty feet; or upon a
court at least two feet in width and extending the entire depth of the
lot from the street to the yard. All such yards and courts shall be
measured at the ground level from the lot line to the building line
opposite on the same lot. The windows in each such room shall have an
aggregate glazed area of at least one-eighth of the total floor area of
the room, and in no event less than twelve square feet. The top edge of
the glazed area of every window shall be nine inches or more below the
finished ceiling and one foot or more above the level of the adjoining
ground. Every such window shall be so constructed that one-half or more
of its area may be opened, and shall be so located as to light and
ventilate adequately all portions of the room.
4. Any room on a top story may be lighted and ventilated by a skylight
of the dimensions specified for windows and arranged to provide
ventilating openings of six square feet or more. Such a skylight shall
be accepted in lieu of a window. Nothing in this subdivision shall be
construed to prohibit the installation of a skylight without ventilating
openings of six square feet or more, provided, however, that such
skylight shall be equipped with at least one hundred forty-four square
inches of ventilation and provided that the glazed area of such skylight
together with the glazed area of any existing window shall be not less
than one-eighth the superficial floor area of such room.
5. When required by the department transoms, or louvres, or partition
sash to private halls or to adjoining rooms in the same apartment shall
be provided to secure thorough ventilation, but no such transom or
louvres or partition sash shall be required in rooms having two windows
opening to the outer air if each window contains at least twelve square
feet of area nor in rooms having a mullioned window with an aggregate
area of at least twenty-four square feet.

S 174. Size of rooms. Every living room shall contain five hundred
fifty cubic feet or more of air, shall be at least six feet wide at its
narrowest part and shall have a minimum height of seven feet if such
room is in the basement, of seven feet at all points more than six feet
from the front of such room if it is on the top story, and of eight feet
if on any other story, except that whenever a basement conforms to the
provisions of subdivision four of section one hundred seventy-seven the
living rooms in such basement may have a minimum height of six feet
eight inches from the finished floor to the bottom of any beams
projecting below the level of the finished basement ceiling and of seven
feet to the ceiling between such beams.

S 175. Alcoves. 1. Every alcove, except a cooking space or foyer,
shall be deemed a living room and shall open into an immediately
adjoining living room which opens directly on a yard or street and in
buildings not over two stories in height, such living room may open
directly on an outer court or on a court, not less than four feet in
width, extending from street to yard. Such an alcove shall be separately
lighted and ventilated, and of such size as provided for other living
rooms, unless it has an opening at least thirty-two and one-half square
feet or more in area opening into a living room immediately adjoining.
2. No part of any room shall be enclosed or subdivided at any time,
wholly or in part, by a curtain, portiere, fixed or movable partition or
any other device unless each enclosed or subdivided part meets all of
the requirements for a separate living room or a lawful alcove.

S 176. Cooking spaces. If space exists or is provided for cooking,
such space shall comply with the provisions of section thirty-three.

S 177. Rooms in basements and cellars. 1. No room in any cellar shall
be occupied for living purposes, except as provided in subdivision six
of section thirty-four or in subdivision three of this section.
2. A room occupied for living purposes in a basement shall comply with
the requirements of sections one hundred seventy-three and one hundred
seventy-four except as provided in subdivision four of this section.
3. Where more than sixty per centum of the height of a cellar is below
the level of the curb on which a dwelling faces, but the floor of such
cellar is approximately at the level of the yard thereof and such yard
is not less than thirty feet in depth at every point, the department may
permit the use of such cellar for living purposes if it shall deem such
cellar adequately lighted and ventilated and habitable. When permission
is granted such a cellar shall be deemed a basement.
4. The basement of a converted dwelling may be used for living
purposes without meeting the requirements of subdivisions one and two of
section one hundred seventy-three if such dwelling meets the other
applicable requirements of such section and of this chapter, including
the following:
a. Such a dwelling shall not exceed three stories, including the
basement, in height.
b. It shall be occupied by not more than one family on any story,
including the basement. For the purposes of this subdivision a family
shall not be deemed to include any boarders, lodgers or roomers.
c. It shall have at least one court two feet or more in width
extending across the entire depth of the lot from the street to the
yard.
d. The department shall deem the basement to be adequately lighted and
ventilated, free of any dampness, sanitary and habitable.
e. There shall be a separate water-closet compartment within the
basement apartment conforming to the provisions of section two hundred.
f. Such dwelling shall not be required to comply with section one
hundred eighty-seven if a scuttle is provided conforming to section one
hundred eighty-eight.
(g) This subdivision is applicable only to buildings noted, classified
or recorded as such converted dwellings in the department prior to
January first, nineteen hundred sixty-six.
5. Notwithstanding any provisions of this section or of subdivision
five of section three hundred, an apartment or room in a cellar which
was occupied for living purposes at any time on or after October first,
nineteen hundred fifty-two may thereafter continue to be occupied for
such purposes until July first, nineteen hundred sixty-seven in
accordance with the conditions imposed by subdivision five of section
two hundred sixteen.

S 178. Lighting and ventilation of stairs. Where the stair and public
halls are not provided on each story with windows opening to a street,
yard or court, a skylight equipped with ridge ventilators having an
opening of forty square inches or more shall be provided in the roof
over the stair, except as otherwise provided in paragraph g of
subdivision three of section one hundred seventy-one. The glazed roof of
such skylight shall not be less in area than nine square feet nor less
than two feet in its least dimension, provided the ventilating and glass
areas in such skylight are not less than herein required; except that in
dwellings converted before April eighteenth, nineteen hundred
twenty-nine, where a skylight smaller than such prescribed dimensions
was in existence on such date, no structural change shall be required,
but a ventilating skylight fitting the existing skylight opening in the
roof beams shall be deemed sufficient.

S 179. Privacy. In every apartment of three or more rooms in every
class A converted dwelling there shall be access to every living room
without passing through any bedroom, and to at least one water-closet
compartment within the apartment from every bedroom without passing
through any other bedroom.