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Section 508 Incidental Use Areas and Mixed Occupancies
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Where a building or portion thereof contains two or more occupancies or uses, the building or portion thereof shall comply with the applicable provisions of this section. For additional requirements for mixed occupancies, see Section 506.4.1.
Incidental use areas shall comply with the provisions of this section.
Exception: Incidental use areas within and serving a dwelling unit are not required to comply with this section.
A space that is listed in Table 508.2 and is incidental to a main occupancy shall be considered an incidental use area. An incidental use area shall be classified in accordance with the main occupancy to which the use is incidental; or such area shall be classified in accordance with its actual occupancy and shall comply with Section 508.3 for mixed occupancies.
| ROOM OR AREA | SEPARATIONa |
|---|---|
| Furnace room where any piece of equipment is over 400,000 Btu per hour input |
2 hour; or 1 hour and provide automatic fire-extinguishing system |
| Furnace room where any piece of equipment is 400,000 Btu per hour input or less, except in R-3 occupancy |
1 hour or provide automatic sprinkler systemb |
| Rooms with any boiler over 15 psi and 10 horsepower | 2 hour; or 1 hour and provide automatic fire-extinguishing system |
| Rooms with any boiler 15 psi or less and 10 horsepower or less, except in R-3 occupancy |
1 hour or provide automatic sprinkler system |
| Mechanical and/or electrical equipment room, except in R-3 occupancy |
1 hour or provide automatic sprinkler system |
| Refrigerant machinery rooms | 1 hour or provide automatic sprinkler system |
| Parking garage (Section 406.2) | 2 hours; or 1 hour and provide automatic fire-extinguishing system |
| Hydrogen cut-off rooms | 2-hour fire barriers and floor/ceiling assemblies in all occupancy groups |
| Incinerator rooms | 2 hours and automatic sprinkler system |
| Paint shops, not classified as Group H, located in occupancies other than Group F |
2 hours; or 1 hour and provide automatic fire-extinguishing system |
| Laboratories and vocational shops, not classified as Group H, located in Group E or I-2 occupancies |
2 hour; or 1 hour and provide automatic fire-extinguishing system |
| Laundry rooms over 100 square feet, except within dwelling units | 1 hour or provide automatic fire-extinguishing system |
| Storage rooms over 100 square feet, except in R-3 occupancy | 1 hour or provide automatic fire-extinguishing system |
| Group I-3 cells equipped with padded surfaces | 1 hour |
| Group I-2 waste and linen collection rooms | 1 hour |
| Waste and linen collection rooms over 100 square feet | 1 hour or provide automatic fire-extinguishing system |
| Stationary lead-acid battery systems having a liquid capacity of more than 100 gallons used for facility emergency power or uninterrupted power supplies |
2-hour fire barriers and floor/ceiling assemblies in all occupancy groups |
| Rooms utilizing the electrical installation standards for "information technology rooms" as per Section 645.1 of the New York City Electrical Code |
As may be required by the New York City Electrical Code |
For SI: 1 square foot = 0.0929 m
2, 1 pound per square inch = 6.9kPa, 1 British thermal unit = 0.293 watts, 1 horsepower = 746 watts, 1 gallon = 3.785 L.
- Where an automatic fire - extinguishing system is provided, it need only be provided in the incidental use room or area.
- Multiple dwellings shall also comply with Section 65 of the New York State Multiple Dwelling Law.
The actual floor area of an incidental use area shall be treated as being in the same occupancy group as its main occupancy for the purposes of calculating allowable height and area in accordance with Section 503.1.
Incidental use areas shall be separated or protected, or both, from all other occupancies in accordance with Table 508.2.
Where Table 508.2 requires a fire-resistance-rated separation, the incidental use area shall be separated from the remainder of the building by a fire barrier constructed in accordance with Section 706 or a horizontal assembly constructed in accordance with Section 711, or both. Where Table 508.2 permits an automatic fire-extinguishing system without a fire barrier, the incidental use area shall be separated from the remainder of the building by construction capable of resisting the passage of smoke. The partitions shall extend from the floor to the underside of the fire-resistance-rated floor/ceiling assembly or fire-resistance-rated roof/ceiling assembly above or to the underside of the floor or roof sheathing, or sub deck above. Doors shall be self- or automatic closing upon detection of smoke in accordance with Section 715.4.7.3. Doors shall not have air transfer openings and shall not be undercut in excess of the clearance permitted in accordance with NFPA 80.
Where an automatic fire-extinguishing system or an automatic sprinkler system is provided in accordance with Table 508.2, only the incidental use areas need be equipped with such a system.
Each portion of a building shall be individually classified in accordance with Section 302.1. Where a building contains more than one occupancy group, the building or portion thereof shall comply with Sections 508.3.1, 508.3.2, 508.3.3 or a combination of these sections.
Exceptions:
- Occupancies separated in accordance with Section 509.
- Where required by Table 415.3.2, areas of Group H-1, H-2 or H-3 occupancies shall be located in a separate and detached building or structure.
- Incidental use areas in accordance with Section 508.2.
Accessory occupancies are those occupancies subsidiary to the main occupancy of the building or portion thereof. In addition, the aggregate of all accessory occupancies located on a single story shall not occupy more than 10 percent of the floor area of the story in which they are located and shall not exceed the tabular values in Table 503 for each such accessory occupancy, without height and area increases in accordance with Sections 504 and 506 for such accessory occupancies.
Exceptions:
-
The following accessory occupancies are permitted to occupy more than 10 percent of the floor area of the story in which they are located:
- Accessory assembly areas having a floor area less than 750 square feet (69.7 m2).
- Assembly areas that are accessory to Group E occupancies.
- Accessory religious educational rooms and religious auditoriums with occupant loads of less than 100.
- Rooms or spaces within Group H-2, H-3, H-4 or H-5 occupancy shall not be considered accessory occupancies and shall be treated as separated occupancies in accordance with Section 508.3.3.
Each accessory occupancy shall be individually classified in accordance with Section 302.1. All code requirements shall apply to each accessory occupancy based upon its individual occupancy classification, except that the most restrictive applicable provisions of Section 403 and Chapter 9 shall apply to the entire building or portion thereof.
The allowable height and area of the building shall be based on the allowable height and area for the main occupancy in accordance with Section 503.1. The height and area of any accessory occupancy shall not exceed the tabular values in Table 503, without height and area increases in accordance with Sections 504 and 506 for such accessory occupancies.
Buildings or portions of buildings that comply with the provisions of this section shall qualify as nonseparated occupancies.
Nonseparated occupancies shall be individually classified in accordance with Section 302.1. All code requirements shall apply to each portion of the building based on the occupancy classification of that space, except that the most restrictive applicable provisions of Section 403 and Chapter 9 shall apply to the entire building or portion thereof.
The allowable height and area of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration for the type of construction of the building in accordance with Section 503.1.
No separation is required between occupancies.
Buildings or portions of buildings that comply with the provisions of this section shall qualify as separated occupancies.
Separated occupancies shall be individually classified in accordance with Section 302.1. Each fire area shall comply with this code based on the occupancy classification of that portion of the building.
In each story, the building area shall be such that the sum of the ratios of the actual floor area of each occupancy divided by the allowable area of each occupancy shall not exceed one.
Each occupancy shall comply with the height limitations based on the type of construction of the building in accordance with Section 503.1. The height, in both feet and stories, of each fire area shall be measured from grade plane. This measurement shall include the height, in both feet and stories, of intervening fire areas.
Exception: Special provisions permitted by Section 509.
Individual occupancies shall be separated from adjacent occupancies in accordance with Table 508.3.3. Where the building is equipped throughout with an automatic sprinkler system, installed in accordance with Section 903.3.1.1, the fire-resistance ratings in Table 508.3.3 are permitted to be reduced by 1 hour, but in no case shall be less than that required for floor construction according to the type of construction, or less than 1 hour, whichever is higher.
Exception: Fire separations of Group H and I-2 occupancies shall not be permitted any reductions in fire-resistance ratings.
Required separations shall be fire barriers constructed in accordance with Section 706 or horizontal assemblies constructed in accordance with Section 711, or both, so as to completely separate adjacent occupancies.
Related Code Sections
Section 508 General Building Heights and Areas; Separation of Occupancies, Incidental Use Areas and Mixed Occupancies
be classified in accordance with its actual occupancy and shall comply with Section 508.3 for mixed occupancies.
TABLE 508.2
INCIDENTAL USE AREAS ...
NYC Building Code 2008 > 5 General Building Heights and Areas; Separation of Occupancies > 508 Incidental Use Areas and Mixed Occupancies
302.1.1 Use and Occupancy Classification, Incidental Use Areas and Mixed Occupancies Including Accessory Occupancies
Structures with multiple occupancies or uses shall comply with Section 508 ...
NYC Building Code 2008 > 3 Use and Occupancy Classification > 302 Classification > 302.1 General > 302.1.1 Incidental Use Areas and Mixed Occupancies Including Accessory Occupancies
508.3 General Building Heights and Areas; Separation of Occupancies, Mixed Occupancies
in a separate and detached building or structure.
Incidental use areas in accordance with Section 508.2 ...
NYC Building Code 2008 > 5 General Building Heights and Areas; Separation of Occupancies > 508 Incidental Use Areas and Mixed Occupancies > 508.3 Mixed Occupancies
508.2 General Building Heights and Areas; Separation of Occupancies, Incidental Use Areas
and shall comply with Section 508.3 for mixed occupancies.
TABLE 508.2
INCIDENTAL USE AREAS
ROOM OR AREA
SEPARATION ...
NYC Building Code 2008 > 5 General Building Heights and Areas; Separation of Occupancies > 508 Incidental Use Areas and Mixed Occupancies > 508.2 Incidental Use Areas
508.3.3.2 General Building Heights and Areas; Separation of Occupancies, Allowable Area
In each story, the building area shall be such that the sum of the ratios of the actual floor area of each occupancy divided by the allowable area ...
NYC Building Code 2008 > 5 General Building Heights and Areas; Separation of Occupancies > 508 Incidental Use Areas and Mixed Occupancies > 508.3 Mixed Occupancies > 508.3.3 Separated Occupancies > 508.3.3.2 Allowable Area