CBC · California Building Code

Mixed occupancies — rules, separation and mixed‑use calculations

Q: When do I have to separate occupancies with a fire barrier?

You must provide rated separation when you elect the separated‑use method (see §508.4) or when the code specifically requires separation for certain groups (exceptions in §508.2 and §508.3). The specific rating (hours) required is listed in Table 508.4 and the fire‑barrier rules are cross‑referenced in §707.3.9.

Q: How do I calculate allowable area for mixed occupancies?

Use the Equation in Section 506 (A_a = A_t + (NS × I_f)) with the tabular A_t values from Table 506.2. For mixed occupancies follow §508.3.2 (nonseparated — use the most restrictive allowances for the whole area) or §508.4.2 (separated — evaluate each separated occupancy individually).

Q: Are accessory uses always unseparated and unlimited in size?

No. Accessory occupancies are unseparated from the main occupancy (§508.2.4) but are limited to an aggregate of not more than 10% of the story area and must not exceed tabular nonsprinklered values in Table 506.2 for each accessory occupancy (§508.2.3).

Q: If my building is sprinklered, do I use the sprinklered numbers in Table 506.2?

Yes — use the column/row that corresponds to the sprinkler classification (S1, SM, S13R, etc.) and type of construction. Be careful: NS (nonsprinklered) values are still referenced in some existing building evaluations and in the Equation as the NS factor term; read the Table 506.2 footnotes.

Q: If an H‑occupancy is present, can I mix it with other occupancies?

Group H occupancies are subject to special restrictions; in many cases Group H areas must be separated per Table 508.4 and certain Group H occupancies must be detached; see §508 exceptions and the provisions in Chapter 4 addressing Group H and unlimited area buildings (e.g., §507.8).

The CBC requires every space to be classified and handled by accessory, nonseparated or separated mixed‑occupancy rules; area is computed from Table 506.2 and Equation 5‑3, nonseparated areas use the most restrictive allowances while separated areas are evaluated individually and separated by rated construction per Table 508.4.

Ask a question free See coverage

Last reviewed: July 5, 2026

What the code requires — 2-4 sentences

The CBC treats every portion of a building as a separately classified occupancy and requires mixed occupancies to be handled by one of the methods in Section 508: accessory occupancies (§508.2), nonseparated occupancies (§508.3) or separated occupancies (§508.4). Which method applies determines whether you may add allowable areas together, whether you must provide fire‑resistive separations, and which limitations and “most restrictive” requirements govern area, height and egress; see §508.1 for the general rule and the individual method sections for details.

Requirements in detail

Overview of the three methods

Accessory occupancy method (§508.2): small ancillary uses are treated as accessory to the main occupancy; no separation is required except for several specifically listed hazardous or institutional groups. Aggregate accessory area limits and the main‑occupancy’s height/area rules control.
Nonseparated use method (§508.3): where mixed occupancies are not separated by rated construction, treat the fire area/building under the most restrictive allowances applicable to the occupancies present; the most limiting Chapter 9 provisions that apply to any nonseparated occupancy apply to the whole nonseparated area. No separation is required by §508.3.
Separated use method (§508.4): occupancies are separated by fire barriers/horizontal assemblies and then each separated occupancy can be evaluated individually for allowable area, height and other limits, subject to the required fire‑resistance rating of the separating construction (Table 508.4).

What controls allowable area calculations

Section 506 (Building area) requires that mixed‑occupancy allowable areas be determined per the applicable mixed‑occupancy provisions of Section 508: nonseparated occupancies use §508.3.2; separated occupancies use §508.4.2. The formula used for allowable area per story is A_a = A_t + (NS × I_f) (Equation 5‑3 / 5‑1/5‑2 as applicable). See §506.2.2 and Equation 5‑3 for the calculation basis.
Where nonseparated occupancies exist in a high‑rise, the most restrictive Section 403 requirements for those occupancies apply throughout the high‑rise (§508.3.1.1). Where a nonseparated occupancy includes certain institutional conditions (I‑2, Condition 2), the most restrictive I‑2 provisions apply throughout that fire area (§508.3.1.2).

Separation (fire‑resistance) requirements

The separated use method requires rated separations between occupancies; the required separation durations are established in Table 508.4 (see §508.4) — that table prescribes the fire‑resistance rating (hours) required between specific occupancy group combinations.
Fire barriers used where §508.4 applies must meet the fire‑resistance requirements in the code, and Section 707 cross‑references these needs. Section 707.3.9 states that when §508.4 applies the fire barrier separating mixed occupancies shall have a rating not less than that indicated in Table 508.4 (see §707.3.9).

Accessory occupancy specifics

Accessory occupancies are individually classified (§508.2.1) but the building’s allowable height and area are governed by the main occupancy (§508.2.2 and §508.2.3). Aggregate accessory occupancies may not occupy more than 10% of the floor area of the story and must not exceed the tabular NS (nonsprinklered) tabular values in Table 506.2 for each accessory occupancy (even if the building is sprinklered) (§508.2.3). No separation is required between accessory and main occupancy except for specifically enumerated groups (exceptions in §508.2.4).

Decision‑relevant table (quick reference)

Decision item	Key value / rule	Code reference
Methods available	Accessory, Nonseparated, Separated	§508.1
Accessory area cap	Aggregate accessory uses ≤ 10% of story area; tabular NS limits in Table 506.2 still apply to each accessory occupancy	§508.2.3
Nonseparated area rule	Use most restrictive allowances for occupancies; most restrictive Chapter 9 provisions that apply to any nonseparated occupancy apply to the whole area	§508.3.2, §508.3.1
Separated area rule	Each separated occupancy evaluated individually for allowable area/height; separations per Table 508.4	§508.4 and §506.2.2
Where to get allowable area numbers	Table 506.2; Equation 5‑1/5‑2/5‑3 in Section 506 (A_a = A_t + (NS × I_f))	Section 506, Table 506.2, Equation 5‑3
Separation (hours)	See Table 508.4 for required hours; fire barriers per §707.3.9 reference Table 508.4	§508.4 and §707.3.9

Exceptions & special cases

Occupancies separated in accordance with Section 510 are treated under that section rather than the Section 508 mixed‑occupancy rules (§508.1, Exception 1).
Certain hazardous and institutional occupancies (Groups H‑2, H‑3, H‑4, H‑5, L, I‑2, I‑3) must be separated from other occupancies in accordance with §508.4 even if they might otherwise be accessory or small in area (exceptions listed in §508.2 and §508.3). Check the specific exception text in §508.2 and §508.3.
For unlimited area buildings that include Group H use, special rules apply (see §507.8 and §507.9) and the H‑area must be separated per Table 508.4.

Common mistakes

Assuming accessory occupancies can be any size — accessory occupancies are limited (≤10% of the story) and are still subject to Table 506.2 tabular limits for nonsprinklered values even when the building is sprinklered (§508.2.3).
Treating separated occupancies as if they were nonseparated (or vice versa) and computing allowable building area improperly — separated occupancies permit per‑occupancy evaluation; nonseparated must use the most restrictive allowances for the whole area (§508.3.2 and §508.4).
Forgetting that certain occupancies are required to be separated regardless of size (see exceptions in §508.2 and §508.3).
Using the wrong tabular value (NS vs S1 vs SM) when computing allowable areas with Equation 5‑3 — NS is the nonsprinklered tabular factor and is used differently in some existing‑building evaluations; S1/SM/S13R etc. correspond to sprinkler protection/status and story count per footnote definitions in Table 506.2. Read the footnotes carefully when applying A_t and NS.

Worked example — concrete scenario

Scenario (concrete numbers, all citations shown):

Building: two stories above grade, Type II‑B construction, equipped throughout with automatic sprinklers (therefore use SM values in Table 506.2). The building floor area (story being evaluated) = 10,000 ft².
Occupancies on that floor: A‑2 (restaurant) area = 6,000 ft²; Group B (business/office) area = 4,000 ft².
Key code references: mixed‑occupancy rules (§508.1–§508.4), area calculation Equation 5‑3 and Table 506.2 values for SM Type II‑B.

Step 1 — get tabular allowable area (A_t) for each occupancy from Table 506.2 (SM, Type II‑B column):

A‑2 (SM, Type II‑B) allowable tabular factor A_t = 25,500 ft² (from Table 506.2 SM row for A‑2, Type II‑B).
B (SM, Type II‑B) allowable tabular factor A_t = 69,000 ft² (from Table 506.2 SM row for B, Type II‑B).

Step 2 — allowable for the story using the separated‑use method

Because separations are provided between the A‑2 and B spaces (assume you design a rated separation meeting Table 508.4 requirements), each occupancy is evaluated individually.
Compare each actual occupancy area to its allowable A_a (A_t + NS×I_f). For this simple example assume no frontage increase (I_f = 0) so A_a ≈ A_t.
- A‑2: actual 6,000 ft² ≤ allowable 25,500 ft² → OK.
- B: actual 4,000 ft² ≤ allowable 69,000 ft² → OK.
Conclusion (separated evaluation): floor is compliant for area limits. See §508.4 and Equation 5‑3 (506.2.2).

Step 3 — allowable for the story using the nonseparated‑use method

If the A‑2 and B spaces are not separated by rated construction, the whole 10,000 ft² is a nonseparated occupancy area and “the allowable building area, height and number of stories of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration” (§508.3.2). That means you would apply the most limiting tabular A_t (in this case A‑2 = 25,500 ft² is more restrictive than B = 69,000 ft²).
With I_f = 0, the most restrictive A_a = 25,500 ft²; actual 10,000 ft² ≤ 25,500 ft² → compliant.
Conclusion (nonseparated evaluation): still compliant, because the combined area is below the most restrictive allowable occupancy value; see §508.3.2 and §506.2.2.

Notes:

If actual floor area had been larger (for example, 30,000 ft²), the nonseparated method likely would fail because the most restrictive allowable (25,500 ft²) would be exceeded; whereas with rated separation (separated method) each occupancy could still pass individually if each occupancy’s actual area were below its own A_a. That is the essential practical difference between nonseparated and separated methods. See §508.3 and §508.4.

Related provisions (quick list)

§506 (Building area, Equation 5‑1/5‑2/5‑3 and Table 506.2) — basis for allowable area calculations.
§707.3.9 (Fire barrier ratings where §508.4 applies) — cross‑reference that separated occupancies require fire barriers per Table 508.4.
§507 (Unlimited area buildings) — special cases where mixed occupancies and Group H interact with unlimited‑area provisions.
§509 (Incidental uses) and §509.1 (Table 509.1) — incidental uses are handled separately from accessory/mixed rules.
§510 (Special mixed occupancy provisions and tenant separation) — exceptions where §510 applies instead of §508.

Code references

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

CBC § 704.7 High relevance — show source text
Ducts 704.7, 705.11, 706.11, 707.10, 708.9, 709.8, 710.8, 712.1.10.3, 712.1.6, 713.10, 714.1.1, 717 Encroachment, public right-of-way 3202.3.2 Equipment on roof 1511 Equipment platforms 505.3 Fireplaces 2111 Incidental use room Table 509.1

Motion picture projection room 409.3 Permit required 105.1, 105.2 Roof access 1011.12 Seismic inspection and testing 1704.3.2, 1705.13.7 Smoke control system 909 Systems Chapter 28 Mechanically Laminated Decking 2304.9.3 Medical Care (see Institutional I-2) 407.1 Medical Gas Systems 427 Membrane Roof Coverings 1507.11, 1507.12, 1507.13 Membrane Structures 2702.2, 3102 Mercantile Occupancy (Group M) 309 Accessible Chapter 11B Alarm and detection 907.2.6.3.4

Area 503, 505, 506, 507, 508 Covered and open mall buildings 402 Hazardous material display and storage 414.2.5 Height 503, 504, 505, 508 Incidental uses 509

Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.3, 1018.4 Stairway, exit access 1019 Travel distance 402.8, 1006.3, 1017.2, 1006.2.1 Mixed occupancies 508.3, 508.4 Accessory 508.2 Live/work units 508.5 Mall buildings 402 Parking below/above 510.2, 510.7, 510.8, 510.9 Special mixed 510.2 Occupancy exceptions 307.1.1 Plumbing fixtures Chapter 29 Sprinkler protection 903.2.7 Standpipes 905.3.3 Unlimited area 507.4, 507.5, 507.13 Merchandise Pad 1018.4

Metal

Aluminum Chapter 20 Roof coverings 1504.4.2, 1507.4, 1507.5

Steel Chapter 22

INDEX-14 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

INDEX

Pedestrian

Protection at construction site

3303.2, 3306 Walkways and tunnels 3104, 3202.3.4 Penalties 114.4 Penetration-Firestop System Fire-rated horizontal assemblies

714.5.2

Fire-rated walls 714.4.2 Penetrations 714, 717 Fire-resistant assemblies

Exterior wall 705.11

Fire barrier 707.7, 707.10 Fire partition 708.7, 708.9 Fire wall 706.9, 706.11 Horizontal assemblies 714.5

Installation 714.2
CBC § 1010.2.3 High relevance — show source text
Hardware 1010.2.3 Toilet facilities for public pools Chapter 29

Technical Production Areas 410.2.2, 410.5.3 Telephone Exchanges 304 Telescopic Seating (see Bleachers) Temporary Structures 3103 Certificate of occupancy 108.3, 111.3 Conformance 108.2, 3103.1.2 Construction documents 3103.2 Encroachment, public rights-ofway 3202.3 Flood provisions G113 Means of egress 3103.4 Permit 108.1, 3103.1.3 Power, temporary 108.3, 112.2 Structural 3103.6 Termination of approval 108.4 Tenant Separation Covered and open mall building 402.4.2.1, 708.1 Tents (see Temporary Structures) Termites, Protection From 2304.12 Terra Cotta 1404.10, 1411

INDEX-20 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

INDEX

Unlimited Area Buildings 507 Unsafe Structures and Equipment (see Structures, Unsafe) 116 Appeals 113, Appendix B Revocation of permit 105.6 Stop work orders 115 Utilities disconnection 112.3

Unstable Materials 307.3, Table 414.2.5.1, Table 414.5.1, Table 415.6.5, 415.7.1, 415.9 Unusable Space 711.2.6 Use and Occupancy Chapter 3 Accessory 508.2 Classification 302.1

Detailed requirements based on occupancy and use Chapter 4 Incidental uses 509, Table 509.1 Mixed 508.3, 508.4 Use designation 302.2 Utilities 112

Service connection 112.1

Service disconnection 112.3

Temporary connection 112.2 Utility and Miscellaneous Occupancy (Group U) 312 Accessibility Chapters 11A and 11B Agricultural buildings Appendix C Area 503, 505, 506, 507, 508 Flood provisions Appendix G Height 503, 504, 508 Incidental uses 509

Live loads Table 1607.1 Means of egress Exit signs 1013.1 Stairway, exit access 1019 Mixed occupancies 508.3, 508.4 Special provisions Private garages and carports 406.3 Residential aircraft hangars 412.4 Sprinkler protection 903.2.11 Travel distance 1006.2.1, 1006.3,

1017.1 UV Germicidal Irradiation Systems

1211
CBC § 507.12 High relevance — show source text
507.12 Motion picture theaters. In buildings of Type II construction, the area of a motion picture theater located on the first story above grade plane shall not be limited where the building is provided with an automatic sprinkler system throughout in accordance with Section 903.3.1.1 and is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width.

507.13 Covered and open mall buildings and anchor buildings. The area of covered and open mall buildings and anchor buildings not exceeding three stories in height that comply with Section 402 shall not be limited.

SECTION 508—MIXED USE AND OCCUPANCY

508.1 General. 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, 508.4 or 508.5, or a combination of these sections.

Exceptions:
1. Occupancies separated in accordance with Section 510.
2. Where required by Table 415.6.5, areas of Group H-1, H-2 and H-3 occupancies shall be located in a detached building or structure.
508.2 Accessory occupancies. 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.

508.2.1 Occupancy classification. 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.

508.2.2 Allowable building height. 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.

508.2.3 Allowable building area. 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.

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

Exceptions:
1. Group H-2, H-3, H-4 and H-5 and L occupancies shall be separated from all other occupancies in accordance with Section 508.4.
2. Group R-1, R-2, R-2.1, R-2.2 and R-3 dwelling units and sleeping units shall be separated from other dwelling or sleeping units and from accessory occupancies contiguous to them in accordance with the requirements of Section 420. 3. Group I-2 shall be separated from all other occupancies in accordance with Section 508.4. Exception: No separation is required between Group B, E and R-1 sleeping units accessory to Group I-2 and covered exte- rior entrances required by Section 11B-206.4.10 or Section 1224.33.2.1 accessory to Group I-2. 4. Group I-3 shall be separated from all other occupancies in accordance with Section 508.4.

CBC § 13-10 Medium relevance — show source text

13-10 2025 CALIFORNIA EXISTING BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

PERFORMANCE COMPLIANCE METHODS

1305.2.14.1 Categories. The categories for elevator controls are:

Category a—No elevator.
Category b—Any elevator without Phase I emergency recall operation and Phase II emergency in-car operation.
Category c—All elevators with Phase I emergency recall operation and Phase II emergency in-car operation as required by the International Fire Code .
Category d—All meet Category c; or Category b where permitted to be without Phase I emergency recall operation and Phase II emergency in-car operation; and at least one elevator that complies with new construction requirements serves all occupied floors.

1305.2.15 Means of egress emergency lighting. Evaluate the presence of and reliability of means of egress emergency lighting. Under the categories and occupancies in Table 1305.2.15, determine the appropriate value and enter that value into Table 1306.1 under Safety Parameter 1305.2.15, Means of Egress Emergency Lighting, for means of egress and general safety.

TABLE 1305.2.15—MEANS OF EGRESS EMERGENCY LIGHTING VALUES	Col2	Col3	Col4
NUMBER OF EXITS REQUIRED BY *SECTION 1006 OF THEINTERNATIONAL BUILDING CODE***	CATEGORIES	CATEGORIES	CATEGORIES
NUMBER OF EXITS REQUIRED BY *SECTION 1006 OF THEINTERNATIONAL BUILDING CODE***	a	b	c
Two or more exits	NP	0	4
Minimum of one exit	0	1	1
NP = Not Permitted.	NP = Not Permitted.	NP = Not Permitted.	NP = Not Permitted.

1305.2.15.1 Categories. The categories for means of egress emergency lighting are:

Category a—Means-of-egress lighting and exit signs not provided with emergency power in accordance with Section 2702 of the International Building Code .
Category b—Means of egress lighting and exit signs provided with emergency power in accordance with Section 2702 of the International Building Code .
Category c—Emergency power provided to means of egress lighting and exit signs, which provides protection in the event of power failure to the site or building.

1305.2.16 Mixed occupancies. Where a building has two or more occupancies that are not in the same occupancy classification, the separation between the mixed occupancies shall be evaluated in accordance with this section. Where there is no separation between the mixed occupancies or the separation between mixed occupancies does not qualify for any of the categories indicated in Section 1305.2.16.1, the building shall be evaluated as indicated in Section 1305.2, and the value for mixed occupancies shall be zero. Under the categories and occupancies in Table 1305.2.16, determine the appropriate value and enter that value into Table 1306.1 under Safety Parameter 1305.2.16, Mixed Occupancies, for fire safety and general safety. For buildings without mixed occupancies, the value shall be zero. Facilities in Group I-2 occupancies meeting Category a shall be considered to fail the evaluation.

CBC § 903.2.5 Medium relevance — show source text
903.2.5

Ventilation 414.3, 415.9.1.7, 415.11.1.6, 415.11.1.8.1, 415.11.3.2, 415.11.6.8, 415.11.7.4, 415.11.8, 415.11.11, 1202.6 Weather protection 414.6.1 Hazardous Occupancy (Group H), (see Hazardous Materials) 307, 414, 415 Alarms and detection 415.11.2, 415.11.4, 415.11.6.9, 415.11.8, 415.3, 415.5, 907.2.5, 908.1, 908.2 Area 503, 505, 506, 507, 508 Dispersing 414.5, 414.6, 415.6 Gas detection systems 415.11.7 Group provisions H-1 (detonation) 307.3, 415.6.2, 415.7, 415.6.4.1, 415.7.1 H-2 (deflagration) 307.4, 415.8, 415.9 H-3 (physical hazard) 415.10, 307.5, 415.8 H-4 (health hazard) 307.6, 415.10 H-5 (semiconductor) 307.7, 415.11 Height 415.7, 415.8.1, 415.9.1.1, 426.1.1, 503, 504, 505, 506 Incidental uses 509

Interior finishes 416.2.1, 416.3.1, Table 803.13, 804 Live load Table 1607.1

Location on property 414.6.1.2, 415.6 Low hazard 306.3, 311.3 Means of egress Corridors 415.11.2 One means of egress Table 1006.3.4(1), Table 1006.3.4(2) Panic hardware 1006.2.2.2, 1006.2.2.3, 1006.2.2.4, 1010.2.8 Stairway, exit access 1019 Travel distance 1006.3, 1006.2.1, Table 1017.2

Mixed occupancies 508.3, 508.4 Accessory 508.2 Moderate hazard 306.2, 311.2 Multiple hazards 306.2, 311.2 Occupancy exceptions 307.1 Plumbing fixtures Chapter 29 Risk category Table 1604.5 Separation from other occupancies 415.6.1, 508.1, 508.2.4, 508.3.3, 508.4 Smoke and heat removal 910.2 Special provisions based on materials Combustible liquids Table 307.1(1), 307.4, 307.5, 414.2.5, 414.5.3,

415.9.2

Corrosives 307.6, Table 414.2.5.1, 414.3, 415.10.3, Table 415.11.1.1 Explosives 307.3, 307.3.1, Table 415.6.5
CBC § 5-14 Medium relevance — show source text
5-14 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

GENERAL BUILDING HEIGHTS AND AREAS

507.9 Unlimited mixed occupancy buildings with Group H-5. The area of a Group B, F, H-5, M or S building not more than two stories above grade plane shall not be limited where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, and is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width, provided that the following criteria are met:
1. Buildings containing Group H-5 occupancy shall be of Type I or II construction.
2. Each area used for Group H-5 occupancy shall be separated from other occupancies as required in Sections 415.11 and 508.4.
3. Each area used for Group H-5 occupancy shall not exceed the maximum allowable area permitted for such occupancies in Section 503.1 including modifications of Section 506. Exception: Where the Group H-5 occupancy exceeds the maximum allowable area, the Group H-5 shall be subdivided into areas that are separated by 2-hour fire barriers.
507.10 Aircraft paint hangar. The area of a Group H-2 aircraft paint hangar not more than one story above grade plane shall not be limited where such aircraft paint hangar complies with the provisions of Section 412.5 and is surrounded and adjoined by public ways or yards not less in width than one and one-half times the building height.

507.11 Group E buildings. The area of a Group E building not more than one story above grade plane, of Type II, IIIA or IV construction, shall not be limited provided that the following criteria are met:
1. Each classroom shall have not less than two means of egress, with one of the means of egress being a direct exit to the outside of the building complying with Section 1022.
2. The building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
3. The building is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width.
507.12 Motion picture theaters. In buildings of Type II construction, the area of a motion picture theater located on the first story above grade plane shall not be limited where the building is provided with an automatic sprinkler system throughout in accordance with Section 903.3.1.1 and is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width.

507.13 Covered and open mall buildings and anchor buildings. The area of covered and open mall buildings and anchor buildings not exceeding three stories in height that comply with Section 402 shall not be limited.

SECTION 508—MIXED USE AND OCCUPANCY

508.1 General. 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, 508.4 or 508.5, or a combination of these sections.

Exceptions:
1. Occupancies separated in accordance with Section 510.
2. Where required by Table 415.6.5, areas of Group H-1, H-2 and H-3 occupancies shall be located in a detached building or structure.

CBC § 1305.2.15.1 Medium relevance — show source text

1305.2.15.1 Categories. The categories for means of egress emergency lighting are:

Category a—Means-of-egress lighting and exit signs not provided with emergency power in accordance with Section 2702 of the International Building Code .
Category b—Means of egress lighting and exit signs provided with emergency power in accordance with Section 2702 of the International Building Code .
Category c—Emergency power provided to means of egress lighting and exit signs, which provides protection in the event of power failure to the site or building.

TABLE 1305.2.16—MIXED OCCUPANCY VALUESa	Col2	Col3	Col4
OCCUPANCY	CATEGORIES	CATEGORIES	CATEGORIES
OCCUPANCY	a	b	c
A-1, A-2, R	-10	0	10
A-3, A-4, B, E, F, M, S	-5	0	5
I-2	NP	0	5
NP = Not Permitted. a. For fire-resistance ratings between categories, the value shall be obtained by linear interpolation.	NP = Not Permitted. a. For fire-resistance ratings between categories, the value shall be obtained by linear interpolation.	NP = Not Permitted. a. For fire-resistance ratings between categories, the value shall be obtained by linear interpolation.	NP = Not Permitted. a. For fire-resistance ratings between categories, the value shall be obtained by linear interpolation.

1305.2.16.1 Categories. The categories for mixed occupancies are:

Category a—Occupancies separated by minimum 1-hour fire barriers or minimum 1-hour horizontal assemblies, or both.
Category b—Separations between occupancies in accordance with Section 508.4 of the International Building Code .
Category c—Separations between occupancies having a fire-resistance rating of not less than twice that required by Section 508.4 of the International Building Code .

CBC § 407.3 Medium relevance — show source text
Smoke partitions 407.3 Sprinkler protection 407.7, 903.2.6, 903.3.2

Yards 407.10

Institutional I-3 [see Institutional Occupancy (see Group I)] 308.4, 408 Accessibility Chapter 11B Alarm and detection 408.10, 907.2.6.3 Combustible decorations 806.1 Means of egress 408.2, 408.3, 408.4 Occupancy condition 308.4 Security glazing 408.7 Separation 408.5, 408.6 Smoke barrier 408.6

Smoke compartment 408.4.1, 408.6, 408.9 Sprinkler protection 408.11, 903.2.6 Standby/emergency power 2702.2 Institutional I-4 [see Institutional Occupancy (Group I)] 308.5 Accessibility Chapter 11B Adult care 308.5

Alarms and detection 907.2.6

Child care 308.5

Educational 308.5.1 Means of egress Table 1006.2.1, Table 1017.2

Corridor 1020.2

Hardware 1010.2.7, 1010.2.12.1 Sprinkler protection 903.2.6 Institutional Occupancy (Group I) 308 Accessory 508.2 Adult care 308.5

Area 503, 505, 506, 507, 508 Child care 303.1.3, 308.5, 310.4 Group specific provisions Group I-1 (see Institutional I-1) 308.2 Group I-2 (see Institutional I-2) 407, 308.3 Group I-3 (see Institutional I-3) 408, 308.4 Group I-4 (see Institutional I-4) 308.1, 308.5 Height 503, 504, 505, 508 Incidental uses 509

Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Corridors 1020.3

Stairway, exit access 1019

Travel distance 407, 1006.3, 1017.2,

1006.2.1

Mixed occupancies 508.3, 508.4 Occupancy exceptions 303.1.1, 303.1.2, 308.5.1, 308.5.4, 310.4.1 Plumbing fixtures Chapter 29 Risk category Table 1604.5 Standby, emergency power 2702.2 Insulation

Concealed 720.2

Duct insulation 720.1

Exposed 720.3 Fiberboard 720.1, Table 1508.2, 2303.1.6.2, 2303.1.6.3 Foam plastic (see Foam Plastics) 720.1

Loose fill 720.4, 720.6 Pipe insulation 720.1, 720.7 Reflective plastic core 2614 Roof 720.5, 1508 Sound 720, 807, 1206 Thermal 720, 807, 1508 Interior Environment Lighting 1204 Rodentproofing Appendix F Sound transmission 1206
CBC § 303.1.1 Medium relevance — show source text
Roofs

Special Chapter 4 Occupancy Classification Chapter 3 Covered and open mall buildings 402

Detailed requirements Chapter 4 Exceptions 303.1.1, 303.1.4, 305.1.1, 305.2.1, 305.2.3, 307.1.1, 308.5.1, 308.5.4, 310.4.1, 311.1.1

HPM 415.11

Mixed 508, 510 Occupied roofs 302.1, 503.1.4 Occupancy Separation Accessory 508.2 Aircraft related 412.4.1 Nonseparated use method 508.3 Separated use method 508.4 Special provisions 510 Unlimited area buildings 507.1.1, 507.4.1, 507.8 Occupant Evacuation Elevators 403.5.2, 403.6.2, 3008 Occupant Load Business Table 1004.5, 1004.8 Calculated 1004.5 Certificate of occupancy 111 Covered and open mall building 402.8.2

Cumulative 1004.2

Increased 1004.5.1 Multiple function 1004.3 Multiple occupancies 1004.4 Outdoors 1004.7 Seating, fixed 1004.6 Signs 1004.9 Occupiable Roofs 503.1.4, 1004.7, 1006.3, 1009.2.1, 1607.14.2 Office Buildings (see Group B Occupancies) Classification 304

Live loads Table 1607.1, 1607.5 Open Mall Buildings (see Covered and Open Mall Buildings) Opening Protection, Exterior Walls 705.9 Opening Protection, Floors (see Vertical Opening Protection) Opening Protectives 705.9, 706.8, 707.6, 708.6, 709.5, 712.1.13.1, 713.7, 716 Automatic-closing devices 909.5.3 Fire door and shutter assemblies

705.9.2, 712.1.13.1, 716.2.1 Fire windows 716.3.4 Glass unit masonry (see Glass Unit Masonry) 2110.1.1 Glazing 716.1.2 Organic Coatings 418 Organic Peroxides 307.4, 307.5 Oxidizers, Liquid And Solid 307.3, 307.4,

307.5

Panic Hardware 1006.2.2.2, 1006.2.2.4, 1010.2.4, Table 1010.2.4, 1010.2.7, 1010.2.8,

1010.4.1

Parapet, Exterior Wall 705.12, 2109.2.4.3 Construction 705.12.1
CBC § 105.6 Medium relevance — show source text
INDEX

Unlimited Area Buildings 507 Unsafe Structures and Equipment (see Structures, Unsafe) 116 Appeals 113, Appendix B Revocation of permit 105.6 Stop work orders 115 Utilities disconnection 112.3

Unstable Materials 307.3, Table 414.2.5.1, Table 414.5.1, Table 415.6.5, 415.7.1, 415.9 Unusable Space 711.2.6 Use and Occupancy Chapter 3 Accessory 508.2 Classification 302.1

Detailed requirements based on occupancy and use Chapter 4 Incidental uses 509, Table 509.1 Mixed 508.3, 508.4 Use designation 302.2 Utilities 112

Service connection 112.1

Service disconnection 112.3

Temporary connection 112.2 Utility and Miscellaneous Occupancy (Group U) 312 Accessibility Chapters 11A and 11B Agricultural buildings Appendix C Area 503, 505, 506, 507, 508 Flood provisions Appendix G Height 503, 504, 508 Incidental uses 509

Live loads Table 1607.1 Means of egress Exit signs 1013.1 Stairway, exit access 1019 Mixed occupancies 508.3, 508.4 Special provisions Private garages and carports 406.3 Residential aircraft hangars 412.4 Sprinkler protection 903.2.11 Travel distance 1006.2.1, 1006.3,

1017.1 UV Germicidal Irradiation Systems

1211

Valuation or Value (see Fees, Permit) 109.3 Vapor Diffusion Port 202 Vapor Retarders 1202.3, 1404.3, 1404.3.2 Vegetative Artificial decorative 419, 419.1 Vegetative roofs 1505.10, 1507.15 Vehicle Barrier 1607.11 Vehicle Barrier Systems 406.4.2, 1607.11 Vehicle Show Rooms 304 Vehicular Fueling 406.7 Vehicular Gates 3110 Vehicular Repair 406.8

Veneer Cement plaster 1404.16, 1411 Fastening 1404.5 Fiber-cement siding 1404.17, 1411 Glazing 1404.13, 1411 Masonry, adhered 1404.11, 2101.2.1, 2103.2.4 Masonry, anchored 1404.7, 1411, 2101.2.1

Metal 1404.12

Plastic 1411, 2605 Slab-type 1404.9, 1411

Testing Automatic fire-extinguishing systems 904.4

Automatic water mist systems 904.11.3 Building official required 104.2.3.6 Carbon dioxide systems 904.8 Clean agent system 904.10 Dry chemical systems 904.6 Emergency and standby power 2702.4 Fire alarm systems 907.7, 907.8 Fire pumps 913.5 Fire-resistant materials 703.2
CBC § 8.0 Medium relevance — show source text
0 feet|< 8.0 feet|< 8.0 feet| |1CC|20 feet|8.5 feet|168|168| |1C|1C|8.0 feet|8.0 feet|8.0 feet| |1CX|1CX|< 8.0 feet|< 8.0 feet|< 8.0 feet| |1D|10 feet|8.0 feet|337|337| |1DX|1DX|< 8.0 feet|< 8.0 feet|< 8.0 feet| |For SI: 1 foot = 304.8 mm.
a. The allowable strength shear values for the side walls and end walls of the intermodal shipping containers are derived from ISO 1496-1 and reduced by a factor of safety of 5.
b. Container designation type is derived from ISO 668.
c. Limitations of Sections 3114.8.5.1 and 3114.8.5.3 shall apply.|For SI: 1 foot = 304.8 mm.
a. The allowable strength shear values for the side walls and end walls of the intermodal shipping containers are derived from ISO 1496-1 and reduced by a factor of safety of 5.
b. Container designation type is derived from ISO 668.
c. Limitations of Sections 3114.8.5.1 and 3114.8.5.3 shall apply.|For SI: 1 foot = 304.8 mm.
a. The allowable strength shear values for the side walls and end walls of the intermodal shipping containers are derived from ISO 1496-1 and reduced by a factor of safety of 5.
b. Container designation type is derived from ISO 668.
c. Limitations of Sections 3114.8.5.1 and 3114.8.5.3 shall apply.|For SI: 1 foot = 304.8 mm.
a. The allowable strength shear values for the side walls and end walls of the intermodal shipping containers are derived from ISO 1496-1 and reduced by a factor of safety of 5.
b. Container designation type is derived from ISO 668.
c. Limitations of Sections 3114.8.5.1 and 3114.8.5.3 shall apply.|For SI: 1 foot = 304.8 mm.
a. The allowable strength shear values for the side walls and end walls of the intermodal shipping containers are derived from ISO 1496-1 and reduced by a factor of safety of 5.
b. Container designation type is derived from ISO 668.
c. Limitations of Sections 3114.8.5.1 and 3114.8.5.3 shall apply.|

FIGURE 3114.8.5.3(1)—BRACING UNIT DISTRIBUTION—MAXIMUM LINEAR LENGTH

|max 1/2

CBC § 16A-13 Medium relevance — show source text

storage
warehouses, and repair garages|—|2,000|2,000| |28.|Roofs|All other primary roof members|—|300|300| |28.|Roofs|All roof surfaces subject to mainte-
nance workers|—|300|300| |29.|Schools_d_|Classrooms|40
[DSA-SS]50f|1,000|—| |29.|Schools_d_|Corridors above first floor|80|1,000|1,000| |29.|Schools_d_|First-floor corridors|100|1,000|1,000| |30.|Scuttles, skylight ribs and accessible ceilings|Scuttles, skylight ribs and accessible ceilings|—|200|—| |31.|Sidewalks, vehicular driveways and yards, subject to trucking|Sidewalks, vehicular driveways and yards, subject to trucking|250b|8,000|Section
1607_A_.19| |32.|Stairs and exits|One- and two-family dwellings|40|300|Section
1607_A_.20| |32.|Stairs and exits|All other|100|300|Section
1607_A_.20| |33.|Storage areas above ceilings|Storage areas above ceilings|20|—|—|

2025 CALIFORNIA BUILDING CODE 16A-13

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

TABLE 1607A.1—MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, L, AND MINIMUM CONCENTRATED LIVE LOADS—continued 0	Col2	Col3	Col4	Col5	Col6
OCCUPANCY OR USE	OCCUPANCY OR USE	OCCUPANCY OR USE	UNIFORM (psf)	CONCENTRATE D (pounds)	ALSO SEE SECTION
34.	Storage warehouses (shall be designed for heavier loads if required for antici- pated storage)	Heavy	250b	—	—
34.	Storage warehouses (shall be designed for heavier loads if required for antici- pated storage)	Light	125b	125b	125b
35.	Stores	Retail:	Retail:		—
35.	Stores	First floor	100	1,000	1,000
35.	Stores	Upper floors	75	1,000	1,000
35.	Stores	Wholesale, all floors	125b	1,000	1,000
36.	Vehicle barriers	Vehicle barriers	See Section 1607_A_.11	See Section 1607_A_.11	—
37.	Walkways and elevated platforms (other than exitways)	Walkways and elevated platforms (other than exitways)	60	—	—
38.	Yards and terraces, pedestrian_h_	Yards and terraces, pedestrian_h_	100a	—	—
39.	Storage racks and wall-hung cabinets.	Storage racks and wall-hung cabinets.	Total loadsd	—	—
For SI: 1 inch = 25.4 mm, 1 square inch = 645.

CBC § 5-1. High relevance — show source text
The actual area of any individual floor shall not exceed the allowable area per Equation 5-1.

506.2.2 Mixed-occupancy buildings. The allowable area of each story of a mixed-occupancy building shall be determined in accordance with the applicable provisions of Section 508.3.2 for nonseparated occupancies and Section 508.4.2 for separated occupancies.

For buildings with more than two stories above grade plane, the total building area shall be such that the aggregate sum of the ratios of the actual area of each story divided by the allowable area of such stories, determined in accordance with Equation 5-3 based on the applicable provisions of Section 508.1, shall not exceed three, provided the aggregate sum of the ratios for portions of mixed-occupancy, multistory buildings containing A, E, H, I, L and R occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, including any other associated non-separated occupancies, shall not exceed two.

Equation 5-3 A a = [ A t + ( NS × I f )]

where:

A a = Allowable area (square feet). A t = Tabular allowable area factor (NS, S13R, S13D or SM value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered building, regardless of whether the building is sprinklered.

I f = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

506.2.2.1 Group H-2 or H-3 mixed occupancies. For a building containing Group H-2 or H-3 occupancies, the allowable area shall be determined in accordance with Section 508.4.2, with the automatic sprinkler system increase applicable only to the portions of the building not classified as Group H-2 or H-3.

506.3 Frontage increase. Every building shall adjoin or have access to a public way to receive an area factor increase based on frontage. Area factor increase shall be determined in accordance with Sections 506.3.1 through 506.3.3.

506.3.1 Minimum percentage of perimeter. To qualify for an area factor increase based on frontage, a building shall have not less than 25 percent of its perimeter on a public way or open space. Such open space shall be either on the same lot or dedicated for public use and shall be accessed from a street or approved fire lane.

506.3.2 Minimum frontage distance. To qualify for an area factor increase based on frontage, the public way or open space adjacent to the building perimeter shall have a minimum distance of 20 feet (6096 mm) measured at right angles from the building face to any of the following:
1. The closest interior lot line.
2. The entire width of a street, alley or public way.
3. The exterior face of an adjacent building on the same property.
The frontage increase shall be based on the smallest public way or open space that is 20 feet (6096 mm) or greater, and the percentage of building perimeter having a minimum 20 feet (6096 mm) public way or open space.
CBC § 5-1. Medium relevance — show source text
The allowable area per story of a single-occupancy building with a maximum of two stories above grade plane shall be determined by Equation 5-1. The total allowable area of a single-occupancy building more than two stories above grade plane shall be determined in accordance with Equation 5-2:

Equation 5-2 A a = [ A t + ( NS × I f )] × S a

where:

A a = Allowable area (square feet). A t = Tabular allowable area factor (NS, S13R, S13D or SM value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered building (regardless of whether the building is sprinklered).

I f = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

S a = 3 for other than Group A, E, H, I, L and R occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, where the actual number of stories above grade plane exceeds three.

S a = 2 for Group A, E, H, I, L and R occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, actual number of building stories above grade plane, not to exceed two.

The actual area of any individual floor shall not exceed the allowable area per Equation 5-1.

506.2.2 Mixed-occupancy buildings. The allowable area of each story of a mixed-occupancy building shall be determined in accordance with the applicable provisions of Section 508.3.2 for nonseparated occupancies and Section 508.4.2 for separated occupancies.

For buildings with more than two stories above grade plane, the total building area shall be such that the aggregate sum of the ratios of the actual area of each story divided by the allowable area of such stories, determined in accordance with Equation 5-3 based on the applicable provisions of Section 508.1, shall not exceed three, provided the aggregate sum of the ratios for portions of mixed-occupancy, multistory buildings containing A, E, H, I, L and R occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, including any other associated non-separated occupancies, shall not exceed two.

Equation 5-3 A a = [ A t + ( NS × I f )]

where:

A a = Allowable area (square feet). A t = Tabular allowable area factor (NS, S13R, S13D or SM value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered building, regardless of whether the building is sprinklered.

I f = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

CBC § 508.3 Medium relevance — show source text

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

2025 CALIFORNIA BUILDING CODE 5-15

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

�

GENERAL BUILDING HEIGHTS AND AREAS

508.3.1 Occupancy classification. 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.

508.3.1.1 High-rise buildings. 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.

508.3.1.2 Group I-2, Condition 2 occupancies. Where one of the nonseparated occupancies is Group I-2, Condition 2, the most restrictive requirements of Sections 407, 509 and 712 shall apply throughout the fire area containing the Group I-2 occupancy. The most restrictive requirements of Chapter 10 shall apply to the path of egress from the Group I-2, Condition 2 occupancy up to and including the exit discharge.

508.3.2 Allowable building area, height and number of stories. The allowable building area, height and number of stories 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.

508.3.3 Separation. No separation is required between nonseparated occupancies.

Exceptions:

Group H-2, H-3, H-4 and H-5 , I-2 and L occupancies shall be separated from all other occupancies in accordance with Section 508.4.
Group R-1, R-2, R-2.1, R-2.2 and R-3 dwelling units and sleeping units shall be separated from other dwelling or sleeping units and from other occupancies contiguous to them in accordance with the requirements of Section 420. 3. Where Group I-3 is not the main occupancy and the area is greater than 10 percent of the floor area, it shall be separated per Table 508.4.

508.4 Separated 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)f	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11	Col12	Col13	Col14	Col15	Col16	Col17	Col18	Col19	Col20	Col21	Col22	Col23	Col24	Col25
OCCUPANCY	A, E	A, E	I-4_i, _ **_R-2.

CBC § 101.4.7 Medium relevance — show source text
Existing 101.4.7 Fire walls 706.1 Height (see Height, Building) 502.1, 503, 504, 505, 508, 510 Occupancy classification Chapter 3 Party walls 706.1.1 Relocatable 3113

Replicable Appendix N Building, Existing 202 Building Department 103 Building Official Duties and powers 103, 104 Qualifications Appendix A Records 104.7

Termination A101.4 Building-Integrated Photovoltaic (BIPV) (see Photovoltaic) Built-Up Roof 1507.10 Business Occupancy (Group B) 303.1.1, 303.1.2, 304 Alarms and detection 907.2.2 Ambulatory care facilities 304, 422 Area 503, 505, 506, 507, 508 Height 503, 504, 505, 508, 510 Higher education laboratories 428, 2702.2

Incidental uses 509 Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.3

Stairway, exit access 1019 Travel distance 1006.3, 1017.2,

1006.2.1

Mixed occupancies 508.2, 508.3, 508.4 Accessory 303.1.2, 508.2 Ambulatory care facilities 422 Assembly 303.1.2

Assembly spaces 1030 Exit signs 1013.1 Guards 1015.2, 1030.17 Main exit 1030.3

Open air 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Panic hardware 1010.2.8, 1010.4.1 Smoke-protected 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Travel distance 1006.2.1, 1006.3, 1017.2, 1030.7 Mixed occupancies 508.3, 508.4 Accessory 508.2 Education 303.1.3
CBC § 508.2.2 Medium relevance — show source text
508.2.2 Allowable building height. 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.

508.2.3 Allowable building area. 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.

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

Exceptions:
1. Group H-2, H-3, H-4 and H-5 and L occupancies shall be separated from all other occupancies in accordance with Section 508.4.
2. Group R-1, R-2, R-2.1, R-2.2 and R-3 dwelling units and sleeping units shall be separated from other dwelling or sleeping units and from accessory occupancies contiguous to them in accordance with the requirements of Section 420. 3. Group I-2 shall be separated from all other occupancies in accordance with Section 508.4. Exception: No separation is required between Group B, E and R-1 sleeping units accessory to Group I-2 and covered exte- rior entrances required by Section 11B-206.4.10 or Section 1224.33.2.1 accessory to Group I-2. 4. Group I-3 shall be separated from all other occupancies in accordance with Section 508.4.
508.3 Nonseparated occupancies. Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

2025 CALIFORNIA BUILDING CODE 5-15

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

�

GENERAL BUILDING HEIGHTS AND AREAS

508.3.1 Occupancy classification. 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.

508.3.1.1 High-rise buildings. 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.

508.3.1.2 Group I-2, Condition 2 occupancies. Where one of the nonseparated occupancies is Group I-2, Condition 2, the most restrictive requirements of Sections 407, 509 and 712 shall apply throughout the fire area containing the Group I-2 occupancy. The most restrictive requirements of Chapter 10 shall apply to the path of egress from the Group I-2, Condition 2 occupancy up to and including the exit discharge.

508.3.2 Allowable building area, height and number of stories. The allowable building area, height and number of stories 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.

CBC § 707.3.8 Medium relevance — show source text

707.3.8 Control areas. Fire barriers separating control areas shall have a fire-resistance rating of not less than that required in Section 414.2.4.

707.3.9 Separated occupancies. Where the provisions of Section 508.4 are applicable, the fire barrier separating mixed occupancies shall have a fire-resistance rating of not less than that indicated in Table 508.4 based on the occupancies being separated.

707.3.10 Fire areas. The fire barriers, fire walls, horizontal assemblies or combinations thereof separating a single occupancy into different fire areas shall have a fire-resistance rating of not less than that indicated in Table 707.3.10. The fire barriers, fire walls, horizontal assemblies or combinations thereof separating fire areas of mixed occupancies shall have a fire-resistance rating of not less than the highest value indicated in Table 707.3.10 for the occupancies under consideration.

7-14 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

FIRE AND SMOKE PROTECTION FEATURES

TABLE 707.3.10—FIRE-RESISTANCE-RATING REQUIREMENTS FOR FIRE BARRIERS, FIRE WALLS OR HORIZONTAL ASSEMBLIES BETWEEN FIRE AREAS	Col2
OCCUPANCY GROUP	FIRE-RESISTANCE RATING (hours)
H-1, H-2	4
F-1, H-3, S-1	3
A, B, E, F-2, H-4, H-5, I,L, M, R, S-2	2
U	1

707.3.11 Horizontal separation offsets. The fire-resistance rating of a fire barrier serving as the vertical offset in a horizontal building separation shall comply with Section 510.2.

707.4 Exterior walls. Where exterior walls serve as a part of a required fire-resistance-rated shaft, or separation or enclosure for a stairway, ramp or exit passageway, such walls shall comply with the requirements of Section 705 for exterior walls and the fire-resistance-rated enclosure or separation requirements shall not apply.

Exceptions:

Exterior walls required to be fire-resistance rated in accordance with Section 1021 for exterior egress balconies, Section 1023.7 for interior exit stairways and ramps, Section 1024.8 for exit passageways and Section 1027.6 for exterior exit stairways and ramps.
Exterior walls required to be fire-resistance rated in accordance with Section 1207 of the California Fire Code for enclosure of energy storage systems.

707.5 Continuity. Fire barriers shall extend from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed space, such as the space above a suspended ceiling. Joints and voids at intersections shall comply with Sections 707.8 and 707.9

Exceptions:

Shaft enclosures shall be permitted to terminate at a top enclosure complying with Section 713.12.
Interior exit stairway and ramp enclosures required by Section 1023 and exit access stairway and ramp enclosures required by Section 1019 shall be permitted to terminate at a top enclosure complying with Section 713.12.

CBC § 1606.4 Medium relevance — show source text
1606.4 Photovoltaic, Building-Integrated (BIPV) Roof Covering 1505.8, Tables 1507.1.1(1)–1507.1.1(3), 1507.16, 1512 Photovoltaic, Building-Integrated (BIPV) Roof Panel 1505.8, 1507.17, 1512 Photovoltaic, Building-Integrated (BIPV) System 1505.8, 1512 Photovoltaic (PV) Module 1505.8, 1511.10, 1511.10.1, 1603.1.8.1, 1606.4, 1607.14.3.2 Photovoltaic (PV) Panel 1505.8, 1511.10, 1511.10.1, 1603.1.8.1, 1606.4, 1607.14.3.2 Photovoltaic (PV) Panel System, Ground Mounted 1604.5.2, 1607.14.3.4, 3111.3.6 Photovoltaic (PV) Support Structure, Elevated 1604.5.2, 1607.14.3.3, 3111.3.5 Photovoltaic Panel Systems 1604.5.2, 1607.14.3, 1613.4

Certificates (see Certificate of Occupancy) Change (see Change of Occupancy) Floor loads Table 1607.1 Height in mixed occupancy buildings 504.2

Roofs

Special Chapter 4 Occupancy Classification Chapter 3 Covered and open mall buildings 402

Detailed requirements Chapter 4 Exceptions 303.1.1, 303.1.4, 305.1.1, 305.2.1, 305.2.3, 307.1.1, 308.5.1, 308.5.4, 310.4.1, 311.1.1

HPM 415.11

Mixed 508, 510 Occupied roofs 302.1, 503.1.4 Occupancy Separation Accessory 508.2 Aircraft related 412.4.1 Nonseparated use method 508.3 Separated use method 508.4 Special provisions 510 Unlimited area buildings 507.1.1, 507.4.1, 507.8 Occupant Evacuation Elevators 403.5.2, 403.6.2, 3008 Occupant Load Business Table 1004.5, 1004.8 Calculated 1004.5 Certificate of occupancy 111 Covered and open mall building 402.8.2

Cumulative 1004.2

Increased 1004.5.1 Multiple function 1004.3 Multiple occupancies 1004.4 Outdoors 1004.7 Seating, fixed 1004.6 Signs 1004.9 Occupiable Roofs 503.1.4, 1004.7, 1006.3, 1009.2.1, 1607.14.2 Office Buildings (see Group B Occupancies) Classification 304

CBC § 707.1 Medium relevance — show source text

SECTION 707—FIRE BARRIERS

707.1 General. Fire barriers installed as required elsewhere in this code or the California Fire Code shall comply with this section.

707.2 Materials. Fire barriers shall be of materials permitted by the building type of construction.

707.3 Fire-resistance rating. The fire-resistance rating of fire barriers shall comply with this section.

707.3.1 Shaft enclosures. The fire-resistance rating of the fire barrier separating building areas from a shaft shall comply with Section 713.4.

707.3.2 Interior exit stairway and ramp construction. The fire-resistance rating of the fire barrier separating building areas from an interior exit stairway or ramp shall comply with Section 1023.1.

707.3.3 Enclosures for exit access stairways. The fire-resistance rating of the fire barrier separating building areas from an exit access stairway or ramp shall comply with Section 713.4.

707.3.4 Exit passageway. The fire-resistance rating of the fire barrier separating building areas from an exit passageway shall comply with Section 1024.3.

707.3.5 Horizontal exit. The fire-resistance rating of the separation between building areas connected by a horizontal exit shall comply with Section 1026.1.

707.3.6 Atriums. The fire-resistance rating of the fire barrier separating atriums shall comply with Section 404.6.

707.3.7 Incidental uses. The fire barrier separating incidental uses from other spaces in the building shall have a fire-resistance rating of not less than that indicated in Table 509.1.

707.3.8 Control areas. Fire barriers separating control areas shall have a fire-resistance rating of not less than that required in Section 414.2.4.

7-14 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

FIRE AND SMOKE PROTECTION FEATURES

TABLE 707.3.10—FIRE-RESISTANCE-RATING REQUIREMENTS FOR FIRE BARRIERS, FIRE WALLS OR HORIZONTAL ASSEMBLIES BETWEEN FIRE AREAS	Col2
OCCUPANCY GROUP	FIRE-RESISTANCE RATING (hours)
H-1, H-2	4
F-1, H-3, S-1	3
A, B, E, F-2, H-4, H-5, I,L, M, R, S-2	2
U	1

CBC § 0.0929 Medium relevance — show source text
See Section C102 for unlimited area under certain conditions.|For SI: 1 square foot = 0.0929 m2.
a. See Section C102 for unlimited area under certain conditions.|

C102.2 One-story unlimited area. The area of a one-story Group U agricultural building shall not be limited if the building is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width.

C102.3 Two-story unlimited area. The area of a two-story Group U agricultural building shall not be limited if the building is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width and is provided with an approved automatic sprinkler system throughout in accordance with Section 903.3.1.1.

SECTION C103—MIXED OCCUPANCIES

C103.1 Mixed occupancies. Mixed occupancies shall be protected in accordance with Section 508.

APPENDIX C-2 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

APPENDIX C—GROUP U—AGRICULTURAL BUILDINGS

SECTION C104—EXITS

C104.1 Exit facilities. Exits shall be provided in accordance with Chapter 11A or 11B as applicable.

Exceptions:
1. The maximum travel distance from any point in the building to an approved exit shall not exceed 300 feet (91 440 mm).
2. One exit is required for each 15,000 square feet (1393.5 m [2] ) of area or fraction thereof.
2025 CALIFORNIA BUILDING CODE APPENDIX C-3

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

APPENDIX C-4 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

APPENDIX D – FIRE DISTRICTS

(Not adopted by state agencies)
CBC § 603.1 Medium relevance — show source text
Design Professional in Responsible Charge) Architectural Trim 603.1, 1408.3 Area, Building Chapter 5, 506, Table 506.2 Accessory uses 508.2.3 Aircraft hangars, residential 412.4.5 Allowable area determination 506.2,

506.3

Basements 506.1.3 Buildings on same lot 503.1.2 Covered and open mall building 402.4.1, 402.4.1.1 Enclosed parking garage 406.6.1, 510.3 Equipment platforms 505.3.1 Frontage bonus 506.3 Incidental uses 509.3

Limitations 503, 506 Membrane structures 3102.4

Mezzanines 505.2.1 Mixed construction types 3102.6 Mixed occupancy 508.2.3, 508.3.2, 508.4.2

Modifications 506, 510 Occupied roof 503.1.4 Open mall building 402.4.1 Open parking garage 406.5.4, 406.5.4.1, 406.5.5, 510.2, 510.3, 510.4, 510.7, 510.8, 510.9 Private garages and carports 406.3.1 Special provisions 510 Unlimited area 503.1.1, 503.1.3, 506.1.1, 506.2, 507 Area for Assisted Rescue, Exterior (see Exterior Area for Assisted Rescue) Area of Refuge (see Also Accessible Means of Egress) 202

Requirements 709.4.2, 1009.6 Signage 1009.10, 1009.11, 1009.9, 1013.4, 1143A, 11B-216, 11B-703 Two-way communication 1009.6.5, 1009.8, 1026.6 Where required 1009.2, 1009.3.3, 1009.4.2 Assembly Occupancy (Group A) 303, 1030 Accessibility Chapters 11A and 11B Alarms and detection 907.2.1

Area 503, 506, 507, 508 Bleachers (see Bleachers) Folding and telescopic seating (see Bleachers) General 303.1 Grandstands (see Grandstands) Group-specific provisions A-1 303.2

A-2 303.3

A-3 303.4

A-4 303.5

Motion picture theater 409, 507.12 Special amusement areas 411 Stages and platforms 410 Height 503, 504, 505, 508, 510 Incidental uses 509 Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.2, 1030.9, 1030.10,

1030.11

INDEX-2 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

INDEX
CBC § 411.1 Medium relevance — show source text
Puzzle room 411.1

Amusement Park Structures 303 Accessibility 11B-234, 11B-1002 Anchor Building (see Covered Mall and Open Mall Building) 402 Construction type 402.4.1.2, 507.13 Means of egress 402.8.4.1 Occupant load 402.8.2.3 Separation 402.4.2.2, 402.4.2.3 Sprinkler protection 402.5 Anchorage 1604.8 Braced wall line sills 2308.7.1.1, 2308.7.1.2, 2308.10.7, 2308.10.7.3

Concrete 1901.3 Conventional light-frame construction 2308.7.1, 2308.8.10 Decks 1604.8.3 Seismic anchorage for masonry chimneys 2113.4 Seismic anchorage for masonry fireplaces 2111.5 Walls 1604.8.2

Wood sill plates 2308.7.1 Apartment Houses 310.3 Appeals 113, 1.8.8, Appendix B, G106 Approved (definition) 202 Approved Agency 104.4, 1703.1 Approved Listing Agency (definition) 202 Approved Testing Agency (definition) 202 Architect (see Definitions for Registered Design Professional and Registered

Design Professional in Responsible Charge) Architectural Trim 603.1, 1408.3 Area, Building Chapter 5, 506, Table 506.2 Accessory uses 508.2.3 Aircraft hangars, residential 412.4.5 Allowable area determination 506.2,

506.3

Basements 506.1.3 Buildings on same lot 503.1.2 Covered and open mall building 402.4.1, 402.4.1.1 Enclosed parking garage 406.6.1, 510.3 Equipment platforms 505.3.1 Frontage bonus 506.3 Incidental uses 509.3

Limitations 503, 506 Membrane structures 3102.4

Mezzanines 505.2.1 Mixed construction types 3102.6 Mixed occupancy 508.2.3, 508.3.2, 508.4.2

Modifications 506, 510 Occupied roof 503.1.4 Open mall building 402.4.1 Open parking garage 406.5.4, 406.5.4.1, 406.5.5, 510.2, 510.3, 510.4, 510.7, 510.8, 510.9 Private garages and carports 406.3.1 Special provisions 510 Unlimited area 503.1.1, 503.1.3, 506.1.1, 506.2, 507 Area for Assisted Rescue, Exterior (see Exterior Area for Assisted Rescue) Area of Refuge (see Also Accessible Means of Egress) 202
CBC § 1305.2.1.1 Medium relevance — show source text
1305.2.1.1 Height formula. The following formulas shall be used in computing the building height value.

Equation 13-1 Height value, feet = (---------------------------------- [AH] ) – ( EBH - ) × CF 12.5

13-4 2025 CALIFORNIA EXISTING BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

PERFORMANCE COMPLIANCE METHODS

Equation 13-2 Height value, stories = ( AS – EBS ) × CF

where:

AH = Allowable height in feet (mm) from Section 504 of the International Building Code .

EBH = Existing building height in feet (mm).

AS = Allowable height in stories from Section 504 of the International Building Code .

EBS = Existing building height in stories.

CF = 1 if ( AH ) – ( EBH ) is positive.

CF = Construction-type factor shown in Table 1305.2.6(2) if ( AH ) – ( EBH ) is negative.

Note: Where mixed occupancies are separated and individually evaluated as indicated in Section 1305.2, the values AH, AS, EBH and EBS shall be based on the height of the occupancy being evaluated.

1305.2.2 Building area. The value for building area shall be determined by the formula in Section 1305.2.2.2. Section 506 of the International Building Code and the formula in Section 1305.2.2.1 shall be used to determine the allowable area of the building. Enter the area value and its sign (positive or negative) in Table 1306.1 under Safety Parameter 1305.2.2, Building Area, for fire safety, means of egress and general safety. In determining the area value, the maximum permitted positive value for area is 50 percent of the fire safety score as listed in Table 1306.2, Mandatory Safety Scores. Group I-2 occupancies shall be scored zero.

1305.2.2.1 Allowable area formula. The following formula shall be used in computing allowable area:

Equation 13-3 A a = A t + ( NS × I f )

where:

A a n= Allowable building area per story (square feet). A t = Tabular allowable area factor (NS, S1, S13R, or SM value, as applicable) in accordance with Table 506.2 of the Inter- national Building Code .

NS = Tabular allowable area factor in accordance with Table 506.2 of the International Building Code for a nonsprinklered building (regardless of whether the building is sprinklered).

I f = Area factor increase due to frontage as calculated in accordance with Section 506.3 of the International Building Code .
CBC § 1305.2.2 Medium relevance — show source text
1305.2.2 Building area. The value for building area shall be determined by the formula in Section 1305.2.2.2. Section 506 of the International Building Code and the formula in Section 1305.2.2.1 shall be used to determine the allowable area of the building. Enter the area value and its sign (positive or negative) in Table 1306.1 under Safety Parameter 1305.2.2, Building Area, for fire safety, means of egress and general safety. In determining the area value, the maximum permitted positive value for area is 50 percent of the fire safety score as listed in Table 1306.2, Mandatory Safety Scores. Group I-2 occupancies shall be scored zero.

1305.2.2.1 Allowable area formula. The following formula shall be used in computing allowable area:

Equation 13-3 A a = A t + ( NS × I f )

where:

A a n= Allowable building area per story (square feet). A t = Tabular allowable area factor (NS, S1, S13R, or SM value, as applicable) in accordance with Table 506.2 of the Inter- national Building Code .

NS = Tabular allowable area factor in accordance with Table 506.2 of the International Building Code for a nonsprinklered building (regardless of whether the building is sprinklered).

I f = Area factor increase due to frontage as calculated in accordance with Section 506.3 of the International Building Code .

1305.2.2.2 Area formula. The following formulas shall be used in computing the area value. Equation 13-4 shall be used for a single occupancy buildings and Equation 13-5 shall be used for multiple occupancy buildings. Determine the area value for each occupancy floor area on a floor-by-floor basis. For multiple occupancy, buildings with the minimum area value of the set of values obtained for the particular occupancy shall be used as the area value for that occupancy.

For single occupancy buildings: Equation 13-4 Area value i = (Allowable area − Actual area)/1200 square feet

For multiple occupancy buildings:

 Actual Actual   area area   ------------------------Allowable i + … + ------------------------Allowable n   area area   i n 

Actual

------------------------Allowablearea i

area i

Equation 13-5

Area value i

Allowable

= --------------------------------------area i - 1 –

1200square feet
- … + -----------------------
------------------------ …

Actual

area

------------------------Allowable n

area n

where:

i = Value for an individual separated occupancy on a floor.

n = Number of separated occupancies on a floor.

CBC § 506.1.3 Medium relevance — show source text

506.1.3 Basements. Basements need not be included in the total allowable floor area of a building provided the total area of such basements does not exceed the area permitted for a one-story above grade plane building.

506.2 Allowable area determination. The allowable area of a building shall be determined in accordance with the applicable provisions of Sections 506.2.1, 506.2.2 and 506.3.

TABLE 506.2—ALLOWABLE AREA FACTOR (A = NS, S1, S13R, S13D or SM, as applicable) IN SQUARE FEETa, b, j t	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11	Col12	Col13	Col14
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	Type I	Type I	Type II	Type II	Type III	Type III	Type IV	Type IV	Type IV	Type IV	Type V	Type V
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	A	B	A	B	A	B	A	B	C	HT	A	B
A-1	NS	UL	UL	15,500	8,500	14,000	8,500	45,000	30,000	18,750	15,000	11,500	5,500
A-1	S1	UL	UL	62,000	34,000	56,000	34,000	180,000	120,000	75,000	60,000	46,000	22,000
A-1	SM_ (without height increase)_	UL	UL	46,500	25,500	42,000	25,500	135,000	90,000	56,250	45,000	34,500	16,500
A-1	SM (with height increase)	UL	UL	15,500	8,500	14,000	8,500	45,000	30,000	18,750	15,000	11,500	5,500
A-2	NS	UL	UL	15,500	9,500	14,000	9,500	45,000	30,000	18,750	15,000	11,500	6,000
A-2	S1	UL	UL	62,000	38,000	56,000	38,000	180,000	120,000	75,000	60,000	46,

CBC § 506.1 Medium relevance — show source text
SECTION 506—CHANGE OF OCCUPANCY

506.1 Compliance. A change of occupancy shall not be made in any building unless that building is made to comply with the requirements of the California Building Code for the use or occupancy. Changes of occupancy in a building or portion thereof shall be such that the existing building is not less complying with the provisions of this code than the existing building or structure was prior to the change. Subject to the approval of the code official, changes of occupancy shall be permitted without complying with all of the requirements of this code for the new occupancy, provided that the new occupancy is less hazardous, based on life and fire risk, than the existing occupancy.

Exception: The building need not be made to comply with Chapter 16 of the California Building Code unless required by Section 506.5.

506.1.1 Change in the character of use. A change of occupancy with no change of occupancy classification shall not be made to any structure that will subject the structure to any special provisions of the applicable California Codes, without approval of the code official. Compliance shall be only as necessary to meet the specific provisions and is not intended to require the entire building be brought into compliance.

506.1.2 Change in function. [OSHPD 1R, 2, 4 and 5] A change in function shall require compliance with all the functional require- ments for new construction in the California Building Code, including requirements in Sections 1224, 1225, 1226, 1227 and 1228.

Exception [OSHPD 1R] : Hospital buildings removed from acute care service adapted for re-use as skilled nursing facilities, acute psychiatric hospitals or out-patient services of a hospital may be permitted to meet the minimum room clearances, areas and dimensions of the 2001 California Building Code for existing rooms re-used for a similar purpose, subject to the approval of OSHPD.

506.2 Certificate of occupancy. A certificate of occupancy shall be issued where it has been determined that the requirements for the new occupancy classification have been met.

506.3 Stairways. An existing stairway shall not be required to comply with the requirements of Section 1011 of the California Build- ing Code where the existing space and construction does not allow a reduction in pitch or slope.

506.4 Existing emergency escape and rescue openings. Where a change of occupancy would require an emergency escape and rescue opening in accordance with Section 1031.1 of the California Building Code, operable windows serving as the emergency escape and rescue opening shall comply with the following:
1. An existing operable window shall provide a minimum net clear opening of 4 square feet (0.38 m [2] ) with a minimum net clear opening height of 22 inches (559 mm) and a minimum net clear opening width of 20 inches (508 mm).
2. A replacement window where such window complies with both of the following: 2.1. The replacement window meets the size requirements in Item 1. 2.2. The replacement window is the manufacturer’s largest standard size window that will fit within the existing frame or existing rough opening. The replacement window shall be permitted to be of the same operating style as the existing window or a style that provides for an equal or greater window opening area than the existing window.
[BS] 506.5 Structural. Any building undergoing a change of occupancy shall satisfy the requirements of this section.
CBC § 0.0929 Medium relevance — show source text
000| |R-4h|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D|S13D| |R-4h|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R|S13R| |R-4h|S1|UL|UL|96,000|64,000|96,000|64,000|246,000|164,000|102,500|82,000|48,000|28,000| |R-4h|SM_ (without height increase)_|UL|UL|72,000|48,000|72,000|48,000|184,500|123,000|76,875|61,500|36,000|21,000| |R-4h|SM (with height increase)|UL|UL|24,000|16,000|24,000|16,000|61,500|41,000|25,625|20,500|12,000|7,000| |S-1|NS|UL|48,000|26,000|17,500|26,000|17,500|76,500|51,000|31,875|25,500|14,000|9,000| |S-1|S1|UL|192,000|104,000|70,000|104,000|70,000|306,000|204,000|127,500|102,000|56,000|36,000| |S-1|SM|UL|144,000|78,000|52,500|78,000|52,500|229,500|153,000|95,625|76,500|42,000|27,000| |S-2|NS|UL|79,000|39,000|26,000|39,000|26,000|115,500|77,000|48,125|38,500|21,000|13,500| |S-2|S1|UL|316,000|156,000|104,000|156,000|104,000|462,000|308,000|192,500|154,000|84,000|54,000| |S-2|SM|UL|237,000|117,000|78,000|117,000|78,000|346,500|231,000|144,375|115,500|63,000|40,500| |U|NSi|UL|35,500|19,000|8,500|14,000|8,500|54,000|36,000|22,500|18,000|9,000|5,500| |U|S1|UL|142,000|76,000|34,000|56,000|34,000|216,000|144,000|90,000|72,000|36,000|22,000| |U|SM|UL|106,500|57,000|25,500|42,000|25,500|162,000|108,000|67,500|54,000|27,000|16,500| |For SI: 1 square foot = 0.0929 m2.
UL = Unlimited; NP = Not Permitted;
CBC § 507.8.1.1.1 Medium relevance — show source text
507.8.1.1.1 Rooms for flammable or combustible liquid use, dispensing or mixing in open systems. Rooms for flammable or combustible liquid use, dispensing or mixing in open systems having a floor area of not more than 500 square feet (46.5 m [2] ) need not be located on the outer perimeter of the building where they are in accordance with the California Fire Code and NFPA 30.

507.8.1.1.2 Liquid storage rooms and rooms for flammable or combustible liquid use in closed systems. Liquid storage rooms and rooms for flammable or combustible liquid use in closed systems having a floor area of not more than 1,000 square feet (93 m [2] ) need not be located on the outer perimeter where they are in accordance with the California Fire Code and NFPA 30.

507.8.1.1.3 Spray paint booths. Spray paint booths that comply with the California Fire Code need not be located on the outer perimeter.

507.8.2 Located on building perimeter. Except as provided for in Section 507.8.1.1, Group H occupancies shall be located on the perimeter of the building. In Group H-2 and H-3 occupancies, not less than 25 percent of the perimeter of such occupancies shall be an exterior wall.

507.8.3 Occupancy separations. Group H occupancies shall be separated from the remainder of the unlimited area building and from each other in accordance with Table 508.4.

507.8.4 Height limitations. For two-story, unlimited area buildings, Group H occupancies shall not be located more than one story above grade plane unless permitted based on the allowable height and number of stories and feet as specified in Section 504 based on the type of construction of the unlimited area building.

5-14 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

GENERAL BUILDING HEIGHTS AND AREAS

507.9 Unlimited mixed occupancy buildings with Group H-5. The area of a Group B, F, H-5, M or S building not more than two stories above grade plane shall not be limited where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, and is surrounded and adjoined by public ways or yards not less than 60 feet (18 288 mm) in width, provided that the following criteria are met:
1. Buildings containing Group H-5 occupancy shall be of Type I or II construction.
2. Each area used for Group H-5 occupancy shall be separated from other occupancies as required in Sections 415.11 and 508.4.
3. Each area used for Group H-5 occupancy shall not exceed the maximum allowable area permitted for such occupancies in Section 503.1 including modifications of Section 506. Exception: Where the Group H-5 occupancy exceeds the maximum allowable area, the Group H-5 shall be subdivided into areas that are separated by 2-hour fire barriers.
507.10 Aircraft paint hangar. The area of a Group H-2 aircraft paint hangar not more than one story above grade plane shall not be limited where such aircraft paint hangar complies with the provisions of Section 412.5 and is surrounded and adjoined by public ways or yards not less in width than one and one-half times the building height.
CBC § 1006.2.2.1 Medium relevance — show source text
Exits 1006.2.2.1

Bolts

Anchor rods 1901.3 Bonding, Masonry 1805.2.2, 2103.2.2, 2113.3.1, 2510.7 Bottle-Filling Stations 202 Braced Wall Line 202

Bracing 2308.10 Seismic requirements 2308.10.10.2, 2308.10.6.2, 2308.10.8 Sill anchorage 2308.10.7.3 Spacing 2308.10.1 Support 2308.10.8 Temporary 3103.5 Braced Wall Panel 202 Alternative bracing 2308.10.5.1, 2308.10.5.2

Connections 2308.10.7 Length 2308.10.4 Location 2308.10.2

Method 2308.10.3 Brick (see Masonry) Building Area (see Area, Building) 502.1, 503, 505, 506, 507, 508, 510 Demolition 3303

Existing 101.4.7 Fire walls 706.1 Height (see Height, Building) 502.1, 503, 504, 505, 508, 510 Occupancy classification Chapter 3 Party walls 706.1.1 Relocatable 3113

Replicable Appendix N Building, Existing 202 Building Department 103 Building Official Duties and powers 103, 104 Qualifications Appendix A Records 104.7

Termination A101.4 Building-Integrated Photovoltaic (BIPV) (see Photovoltaic) Built-Up Roof 1507.10 Business Occupancy (Group B) 303.1.1, 303.1.2, 304 Alarms and detection 907.2.2 Ambulatory care facilities 304, 422 Area 503, 505, 506, 507, 508 Height 503, 504, 505, 508, 510 Higher education laboratories 428, 2702.2

Incidental uses 509 Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.3

Stairway, exit access 1019 Travel distance 1006.3, 1017.2,

1006.2.1

Mixed occupancies 508.2, 508.3, 508.4 Accessory 303.1.2, 508.2 Ambulatory care facilities 422 Assembly 303.1.2

Assembly spaces 1030 Exit signs 1013.1 Guards 1015.2, 1030.17 Main exit 1030.3

CBC § 506.2 Medium relevance — show source text

NS = Tabular allowable area factor in accordance with Table 506.2 of the International Building Code for a nonsprinklered building (regardless of whether the building is sprinklered).

I f = Area factor increase due to frontage as calculated in accordance with Section 506.3 of the International Building Code .

1305.2.2.2 Area formula. The following formulas shall be used in computing the area value. Equation 13-4 shall be used for a single occupancy buildings and Equation 13-5 shall be used for multiple occupancy buildings. Determine the area value for each occupancy floor area on a floor-by-floor basis. For multiple occupancy, buildings with the minimum area value of the set of values obtained for the particular occupancy shall be used as the area value for that occupancy.

For single occupancy buildings: Equation 13-4 Area value i = (Allowable area − Actual area)/1200 square feet

For multiple occupancy buildings:

 Actual Actual   area area   ------------------------Allowable i + … + ------------------------Allowable n   area area   i n 

Actual

------------------------Allowablearea i

area i

Equation 13-5

Area value i

Allowable

= --------------------------------------area i - 1 –

1200square feet

… + -----------------------

------------------------ …

Actual

area

------------------------Allowable n

area n

where:

i = Value for an individual separated occupancy on a floor.

n = Number of separated occupancies on a floor.

1305.2.3 Compartmentation. Evaluate the compartments created by fire barriers or horizontal assemblies which comply with Sections 1305.2.3.2 and 1305.2.3.3and which are exclusive of the wall elements considered under Sections 1305.2.4 and 1305.2.5. Conforming compartments shall be figured as the net area and do not include shafts, chases, stairways, walls or columns. Using Table 1305.2.3, determine the appropriate compartmentation value (CV) and enter that value into Table 1306.1 under Safety Parameter 1305.2.3, Compartmentation, for fire safety, means of egress and general safety.

TABLE 1305.2.3—COMPARTMENTATION VALUES	Col2	Col3	Col4	Col5	Col6
OCCUPANCY	CATEGORIESa	CATEGORIESa	CATEGORIESa	CATEGORIESa	CATEGORIESa
OCCUPANCY	a	b	c	d	e
A-1, A-3	0	6	10	14	18
A-2	0	4	10	14	18
A-4, B, E, S-2	0	5	10	15	20
F, M, R, S-1	0	4	10	16	22
I-2	0	2	8	10	14
a. For compartment sizes between categories, the compartmentation value shall be obtained by linear interpolation.	a.

California Building Code Medium relevance — show source text

laics aabplpel)i cINa bSlQe)U IANR SEQ FUEAERTEa, bF, E j—ETcoa, nb,t jinued t t	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11	Col12	Col13	Col14
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION	TYPE OF CONSTRUCTION
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	Type I	Type I	Type II	Type II	Type III	Type III	Type IV	Type IV	Type IV	Type IV	Type V	Type V
OCCUPANCY CLASSIFICATION	SEE FOOTNOTES	A	B	A	B	A	B	A	B	C	HT	A	B
H-2	NSc	21,000	16,500	11,000	7,000	9,500	7,000	10,500	10,500	10,500	10,500	7,500	3,000
H-2	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1
H-2	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM
H-3	NSc	UL	60,000	26,500	14,000	17,500	13,000	25,500	25,500	25,500	25,500	10,000	5,000
H-3	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1	S1
H-3	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM	SM
H-4	NSc, d	UL	UL	37,500	17,500	28,500	17,500	72,000	54,000	40,500	36,000	18,000	6,500
H-4	S1	UL	UL	150,000	70,000	114,000	70,000	288,000	216,000	162,000	144,000	72,000	26,000
H-4	SM_ (without height increase)_	UL	UL	112,500	52,500	85,500	52,500	216,000	162,000	121,500	108,000	54,000	19,

California Building Code Medium relevance — show source text
000|38,000|56,000|38,000|180,000|120,000|75,000|60,000|46,000|24,000| |A-4|SM_ (without height increase)|UL|UL|46,500|28,500|42,000|28,500|135,000|90,000|56,250|45,000|34,500|18,000| |A-4|SM (with height increase)|UL|UL|15,500|9,500|14,000|9,500|45,000|30,000|18,750|15,000|11,500|6,000| |A-5|NS|UL|UL|UL|UL|UL|UL|UL|UL|UL|UL|UL|UL| |A-5|S1|S1|S1|S1|S1|S1|S1|S1|S1|S1|S1|S1|S1| |A-5|SM|SM|SM|SM|SM|SM|SM|SM|SM|SM|SM|SM|SM| |B|NS|UL|UL|37,500|23,000|28,500|19,000|108,000|72,000|45,000|36,000|18,000|9,000| |B|S1|UL|UL|150,000|92,000|114,000|76,000|432,000|288,000|180,000|144,000|72,000|36,000| |B|SM|UL|UL|112,500|69,000|85,500|57,000|324,000|216,000|135,000|108,000|54,000|27,000| |E|NS|UL|UL|26,500|14,500|23,500|14,500|76,500|51,000|31,875|25,500|18,500|9,500| |E|S1|UL|UL|106,000|58,000|94,000|58,000|306,000|204,000|127,500|102,000|74,000|38,000| |E|SM (without height increase)_|UL|UL|79,500|43,500|70,500|43,500|229,500|153,000|95,625|76,500|55,500|28,500| |E|SM (with height increase)|UL|UL|26,500|14,500|23,500|14,500|76,500|51,000|31,875|25,500|18,500|9.500| |F-1|NS|UL|UL|25,000|15,500|19,000|12,000|100,500|67,000|41,875|33,500|14,000|8,500| |F-1|S1|UL|UL|100,000|62,000|76,000|48,000|402,000|268,000|167,500|134,000|56,000|34,000| |F-1|SM|UL|UL|75,000|46,500|57,000|36,000|301,500|201,000|125,625|100,500|42,000|25,

Frequently asked questions

When do I have to separate occupancies with a fire barrier?

You must provide rated separation when you elect the separated‑use method (see §508.4) or when the code specifically requires separation for certain groups (exceptions in §508.2 and §508.3). The specific rating (hours) required is listed in Table 508.4 and the fire‑barrier rules are cross‑referenced in §707.3.9.

How do I calculate allowable area for mixed occupancies?

Use the Equation in Section 506 (A_a = A_t + (NS × I_f)) with the tabular A_t values from Table 506.2. For mixed occupancies follow §508.3.2 (nonseparated — use the most restrictive allowances for the whole area) or §508.4.2 (separated — evaluate each separated occupancy individually).

Are accessory uses always unseparated and unlimited in size?

No. Accessory occupancies are unseparated from the main occupancy (§508.2.4) but are limited to an aggregate of not more than 10% of the story area and must not exceed tabular nonsprinklered values in Table 506.2 for each accessory occupancy (§508.2.3).

If my building is sprinklered, do I use the sprinklered numbers in Table 506.2?

Yes — use the column/row that corresponds to the sprinkler classification (S1, SM, S13R, etc.) and type of construction. Be careful: NS (nonsprinklered) values are still referenced in some existing building evaluations and in the Equation as the NS factor term; read the Table 506.2 footnotes.

If an H‑occupancy is present, can I mix it with other occupancies?

Group H occupancies are subject to special restrictions; in many cases Group H areas must be separated per Table 508.4 and certain Group H occupancies must be detached; see §508 exceptions and the provisions in Chapter 4 addressing Group H and unlimited area buildings (e.g., §507.8).

Ask about the CBC

Get cited, plain-English answers on the California Building Code for your project — any code section, any scenario.

Start Free Trial

Related in the CBC

Incidental uses and accessory areas (Table 509.1)

Change of occupancy — procedures, approvals and certificate of occupancy

Mixed occupancies, incidental uses & change of occupancy

California Building Code

Mixed occupancies — rules, separation and mixed‑use calculations

What the code requires — 2-4 sentences

Requirements in detail

Overview of the three methods

What controls allowable area calculations

Separation (fire‑resistance) requirements

Accessory occupancy specifics

Decision‑relevant table (quick reference)

Exceptions & special cases

Common mistakes

Worked example — concrete scenario

Related provisions (quick list)

Code references

Frequently asked questions

More in California Building Code

Ask about the CBC

Related in the CBC