N.Y.C. Admin. Code § BC 505: Section BC 505: Mezzanines and Equipment Platforms

505.1 General.

Mezzanines shall comply with Section 505.2. Equipment platforms shall comply with Section 505.3.

505.2 Mezzanines.

A mezzanine or mezzanines in compliance with Section 505.2 shall be considered a portion of the story below. Such mezzanines shall not contribute to either the building area or number of stories as regulated by Section 503.1. The area of the mezzanine shall be included in determining the fire area. The clear height above and below the mezzanine floor construction shall be not less than 7 feet (2134 mm).

Exception: The clear height of habitable spaces above or below mezzanines within dwelling units shall be not less than 8 feet (2438 mm).

505.2.1 Area limitation.

The aggregate area of a mezzanine or mezzanines within a room or space shall be not greater than one-third of the floor area of that room or space in which they are located. The enclosed portions of a room or space shall not be included in determining the permissible floor area of the mezzanine. In determining the allowable mezzanine area, the area of the mezzanine shall not be included in the floor area of the room in which it is contained.

Where a room contains both a mezzanine and an equipment platform, the aggregate area of the two raised floor levels shall be not greater than two-thirds of the floor area of that room or space in which they are located.

Exceptions:

1. The aggregate area of mezzanines in buildings and structures of Type I or II construction for special industrial occupancies in accordance with Section 503.1.1 shall be not greater than two-thirds of the area of the room in which the mezzanines are located.

2. The aggregate area of a mezzanine or mezzanines within a dwelling unit shall not exceed one-third of the net floor area of such dwelling unit, whether or not portions of such dwelling unit are enclosed. The area of the mezzanine shall not contribute to the determination of the floor area of the dwelling unit in which it is contained.

505.2.2 Means of egress.

Each occupant of a mezzanine shall have access to at least two independent means of egress where the common path of egress travel exceeds the limitations of Section 1006.2. Where a stairway provides a means of exit access from a mezzanine, the maximum travel distance includes the distance traveled on the stairway measured in the plane of the tread nosing. Accessible means of egress shall be provided in accordance with Section 1009.

Exception: A single means of egress shall be permitted in accordance with Section 1006.2.

505.2.3 Openness.

A mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls or railings not more than 42 inches (1067 mm) in height, columns and posts.

Exceptions:

1. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space is not greater than 10.

2. A mezzanine having two or more means of egress is not required to be open to the room in which the mezzanine is located, if at least one of the means of egress provides direct access to an exit located on the mezzanine level.

3. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the aggregate floor area of the enclosed space is not greater than 10 percent of the mezzanine area.

4. In industrial facilities, mezzanines used for control equipment are permitted to be glazed on all sides.

5. A mezzanine having two or more means of egress shall not be required to be open to the room in which the mezzanine is located in occupancies, other than Groups H and I, that comply with Items 5.1 through 5.4.

5.1. Such occupancy is no more than two stories above grade plane,

5.2. Such occupancy is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1,

5.3. An approved fire alarm system is installed throughout the entire building or structure in which such occupancy is located, and

5.4. Notification appliances are installed throughout the mezzanine in accordance with NFPA 72.

505.3 Equipment platforms.

Equipment platforms in buildings shall not be considered as a portion of the floor below. Such equipment platforms shall not contribute to either the building area or the number of stories as regulated by Section 503.1. The area of the equipment platform shall not be included in determining the fire area in accordance with Section 903. Equipment platforms shall not be a part of any mezzanine and such platforms and the walkways, stairways, alternating tread devices and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building.

505.3.1 Area limitation.

The aggregate area of all industrial equipment platforms within a room shall be not greater than two-thirds of the area of the room in which they occur. Where an equipment platform is located in the same room as a mezzanine, the area of the mezzanine shall be determined by Section 505.2.1 and the combined aggregate area of the equipment platforms and mezzanines shall be not greater than two-thirds of the room in which they are located.

505.3.2 Fire suppression.

Where located in a building that is required to be protected by an automatic sprinkler system, equipment platforms shall be fully protected by sprinklers above and below the platform, where required by the standards referenced in Section 903.3.

505.3.3 Guards.

Equipment platforms shall have guards where required by Section 1015.2.