Section 508 Mixed Use and Occupancy

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 the applicable provisions of Section 508.2, 508.3 or 508.4, or a combination of these sections.

Accessory occupancies are those occupancies that are ancillary to the main occupancy of the building or portion thereof. Accessory occupancies shall comply with the provisions of Sections 508.2.1 through 508.2.4.

Accessory occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space.

The allowable height and number of stories of the building containing accessory occupancies shall be in accordance with Section 504 for the main occupancy of the building.

The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies 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 for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

No separation is required between accessory occupancies and the main occupancy.

Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

Nonseparated occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space. In addition, the most restrictive provisions of Chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area. Where nonseparated occupancies occur in a high-rise building, the most restrictive requirements of Section 403 that apply to the nonseparated occupancies shall apply throughout the high-rise building.

The allowable building area and height 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 nonseparated occupancies.

Buildings or portions of buildings that comply with the provisions of this section shall be considered as separated occupancies.

TABLE 508.4
REQUIRED SEPARATION OF OCCUPANCIES (HOURS)

OCCUPANCY

A, E

I-1a, I-3, I-4

I-2

Ra

F-2, S-2b, U

Be, F-1, M, S-1

H-1

H-2

H-3, H-4

H-5

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

A, E

N

N

1

2

2

NP

1

2

N

1

1

2

NP

NP

3

4

2

3

2

NP

I-1a, I-3, I-4

‒

‒

N

N

2

NP

1

NP

1

2

1

2

NP

NP

3

NP

2

NP

2

NP

I-2

‒

‒

‒

‒

N

N

2

NP

2

NP

2

NP

NP

NP

3

NP

2

NP

2

NP

Ra

‒

‒

‒

‒

‒

‒

N

N

1c

2c

1

2

NP

NP

3

NP

2

NP

2

NP

F-2, S-2b, U

‒

‒

‒

‒

‒

‒

‒

‒

N

N

1

2

NP

NP

3

4

2

3

2

NP

Be, F-1, M, S-1

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

N

N

NP

NP

2

3

1

2

1

NP

H-1

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

N

NP

NP

NP

NP

NP

NP

NP

H-2

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

N

NP

1

NP

1

NP

H-3, H-4

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

1d

NP

1

NP

H-5

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

‒

N

NP

S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

NS = Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

N = No separation requirement.

NP = Not permitted.

1. See Section 420.
2. The required separation from areas used only for private or pleasure vehicles shall be reduced by 1 hour but not to less than 1 hour.
3. See Section 406.3.4.
4. Separation is not required between occupancies of the same classification.
5. See Section 422.2 for ambulatory care facilities.

Separated occupancies shall be individually classified in accordance with Section 302.1. Each separated space 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 building area of each separated occupancy divided by the allowable building area of each separated occupancy shall not exceed 1.

Each separated occupancy shall comply with the building height limitations based on the type of construction of the building in accordance with Section 503.1.

Individual occupancies shall be separated from adjacent occupancies in accordance with Table 508.4.

Required separations shall be fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both, so as to completely separate adjacent occupancies.