N.Y.C. Admin. Code § EBC D305: D305 Light and air (MDL 3, Title 1).

D305.1 Commercial courts (MDL 26(7)).

Except as otherwise provided in the New York City Zoning Resolution, courts for multiple dwellings classified as commercial uses under the New York City Zoning Resolution, including but not limited to transient hotels as such term is defined in the New York City Zoning Resolution, shall comply with Sections D305.1.1 and D305.1.2 for any court supplying required light and air to living rooms.

D305.1.1 Commercial inner courts (MDL 26(7)(a)).

An inner court shall have minimum width of 4 inches (107 mm) per foot for each 1 foot (305 mm) of height of such court, but in no event less than 15 feet (4572 mm) in width at any point. The area of such inner court shall be twice the square of the width of the court dimension based on the height of such court, but in no event less than 350 square feet (32.5 m

2

) in area. The area of such court need not exceed 1,200 square feet (111.5 m

2

) provided that the minimum horizontal distance between any required window of a living room opening on an inner court shall not be less than 30 feet (9144 mm) from any wall opposite such window. For a dwelling 3 stories or less in height, an inner court may have a minimum width of 3 inches (76 mm) for each 1 foot (305 mm) of height of such court, but in no event less than 10 feet (3048 mm) in width at any point. The area of such court shall be twice the square of the required width of court dimension based on the height of such court but in no event less than 250 square feet (23 m

2

) in area. An air in-take of fireproof construction shall be provided at or near the lowest level of every inner court of dwellings exceeding 2 stories in height, and shall communicate directly with a street or yard. Such in-take shall have a vertical cross-sectional area of not less than 21 square feet (2 m

2

) and a minimum width of not less than 3 feet (914 mm) in its least dimension, and shall be open and unobstructed throughout, except that where the intake is not used as a passage or exit, gates, or grilles which do not interfere with ventilation may be installed.

D305.1.2 Commercial outer courts (MDL 26(7)(b)).

An outer court at any given height shall have a minimum width at least equal to twice the depth of such outer court if such outer court is less than 30 feet (9144 mm) wide. Such outer court shall have a width at least equal to its depth if such court is 30 feet (9144 mm) or more in width. An outer court need not exceed 60 feet (18 288 mm) in width. An outer court on a side lot line may begin at the level of the floor of the lowest story in which there is a living room opening therefrom. Any outer court not on a side lot line may begin at any level, the height of such court to be measured from the level at which such court begins.

D305.2 Conversions and changes of class or kind (MDL 9(2), 9(3)).

Conversions to a multiple dwelling subject to Section D302 and dwellings of 1 class or kind altered or converted to another class or kind subject to Section D303 shall comply with the Chapter of the New York City Building Code relating to court walls for multiple dwellings, natural ventilation, natural light, and interior space dimensions.

D305.3 Department approval required for lighting and ventilation of rooms (MDL 30(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.

D305.3.1 Alcoves (MDL 32).

Except for cubicles permitted in exifsting lodging houses, 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 other contrivance or device, unless each such enclosure or subdivision shall contain a separate window as required for a room by Chapter 12 of the New York City Building Code and a floor space of at least 70 square feet (6.5 m

2

).

D305.4 Rooms in basements and cellars (MDL 34(6)).

D305.4.1 New rooms in basements or cellars (MDL 34(6), 218(2)).

Rooms created after the effective date of the local law that added this section in basements and cellars within dwelling units and, regardless of multiple dwelling classification, shall comply with all of the following requirements, and no other compliance paths in this code or in the MDL shall be applicable:

1. Such dwelling unit has at least one-half of its height and all of its window surfaces above every part of an "adequate adjacent space." Such "adequate adjacent space" shall be open to the sky, properly drained to the satisfaction of the department, and a continuous surface area outside the dwelling not less than 30 feet (9144 mm) in its least dimension and abutting at same level, or directly below, every part of the exterior walls of such dwelling unit and of every other dwelling unit on the same floor. Such "adequate adjacent space" shall include only space which is located on the same zoning lot or plot as the dwelling or on a street or public place or space.

2. Every living room of such dwelling unit is everywhere at least 8 feet (2438 mm) high from the floor to the ceiling in dwellings erected after July 1, 1957, and 7 feet (2134 mm) in dwellings erected prior thereto.

3. All parts of the exterior walls of the dwelling which are below ground level and on the same floor as such dwelling unit or above such floor are dampproof to the satisfaction of the department and the floor of such dwelling unit is dampproof and waterproof.

4. The yard and every court of the dwelling containing such dwelling unit are adequately drained to the satisfaction of the department.

5. If any part of the dwelling unit is below the "adequate adjacent space" referred to in Item 1 of this section, all ceilings, walls, and partitions of such dwelling unit including the studs are constructed of noncombustible materials, except that with respect to existing dwelling units, such existing ceilings, walls, or partitions shall be permitted to remain either fire-retarded or sprinklered.

6. Such dwelling unit and every part of the floor on which it is situated meet all of the requirements which would be in effect for such floor if none of the rooms thereon were used for living purposes.

7. Such dwelling unit complies with all of the requirements for dwelling units in the same dwelling which are not in a cellar or basement.

8. The floor on which such dwelling unit is situated, if a cellar, shall nevertheless be counted as a story for the purpose of all requirements of this appendix except those relating to the height of the dwelling.

D305.4.2 Existing rooms in basements and cellars (MDL 34(5), 177(5), 216(5)).

Existing rooms in cellars and basements within dwelling units shall comply with the provisions of Section D305.4.1, or, based on the multiple dwelling classification, shall be permitted to comply with:

1. Section D402.2 for fireproof buildings classified as HAEA (1929-1968) or HAEB (1929-1968).

2. Section D505.2 for non-fireproof buildings classified as HAEA (1929-1968) or HAEB (1929-1968).

3. Section D605.2 for converted dwellings.

4. Section D702.6.2 for OLs and NLs.

D305.5 Entrance doors (MDL 35).

No alterations or repairs shall be made in doors giving access to an entrance hall from the outside of the dwelling that would reduce the existing area of glazing to less than 5 square feet (0.5 m

2

) of glazed surface. New conversions to a multiple dwelling subject to Section D302 and dwellings of 1 class or kind altered or converted to another class or kind subject to Section D303 shall provide at least 5 square feet (0.5 m

2

) of such glazed area.

D305.6 Existing windows in public halls (MDL 36).

Existing windows in public halls shall be permitted to be removed provided mechanical ventilation is installed in accordance with the

New York City Mechanical Code

.

Exception: Where windows are required for certain NLs in accordance with Chapter D7.

D305.7 Existing skylights in stairs (MDL 36).

Existing skylights in stairs shall be permitted to be removed where smoke vents are installed in accordance with Section 713.12 of the New York City Building Code.

Exception: Where skylights are required for certain OLs and NLs in accordance with Chapter D7 and for certain CAAs and JARs in accordance with MDL 277.

D305.8 Multiple buildings on the same tax lot (MDL 28(2)).

If a multiple dwelling is located anywhere on the same tax lot with another building, any additions or conversions shall not reduce the unoccupied open space between buildings in any way that would result in an increase of noncompliance with Section 28(2) of the MDL.

D305.9 Cubic feet per occupant (MDL 31(6)(a), (b)).

Living rooms created or reconfigured shall provide at least 400 cubic feet (11.3 m

3

) of air for each adult, and 200 cubic feet (5.66 m

3

) of air for each child occupying such room, considering children of 12 years of age or more as adults and 2 children between the ages of 2 and 11 years inclusive as the equivalent of 1 adult. Children under 2 years of age need not be considered as occupants.