CBC · California Building Code
Change of occupancy — procedures, approvals and certificate of occupancy
If your building’s use or classification changes you must get the code official’s approval and—in any case where the CBC finds the occupancy classification has changed—a Certificate of Occupancy will only be issued after required fire‑safety, structural, egress and other code upgrades (or approved exceptions) are satisfied.
Last reviewed: July 5, 2026
What the code requires
Under the California Existing Building Code, you cannot change the use or occupancy classification of a building (or make a change of occupancy within a space that alters fire‑protection thresholds) without the approval of the code official; a certificate of occupancy must be issued when the requirements for the change have been met (see § 1001.2). When a change results in a different occupancy classification a certificate of occupancy is required (§ 1001.3).
Requirements in detail
Who must approve a change of occupancy
- The code official (building official) must approve the change before the building may be made to the new occupancy; the approval requirement is stated in § 1001.2.
When a Certificate of Occupancy (CO) is required
- A CO is required whenever a change of occupancy results in a different occupancy classification under the CBC (§ 1001.3). A CO is also required after the code official inspects and determines the requirements for the new occupancy have been met (§ 1001.2 and the CBC administration provisions governing CO issuance).
Scope of work required for a change
- Any work undertaken with a change in use must conform to applicable requirements for that work and to Sections § 1002 through § 1010; where the building undergoes a change of occupancy classification the provisions of § 1002 through § 1011 apply (§ 1001.2.1 and § 1001.2.2).
Fire protection and life‑safety systems
- If the new occupancy (or a change within a space) changes the fire‑protection system threshold in Chapter 9 of the CBC, required systems (for example, automatic sprinklers or fire alarm/detection) must be provided in accordance with the relevant sections. The installation of an automatic sprinkler system is required where Chapter 9 requires it for the new occupancy, and required fire alarm/detection systems must follow the California Fire Code requirements (§ 1011.2, § 1011.2.1, § 1011.2.2).
Structural, egress and other specific system obligations
- Structural live loads must meet CBC Section 1607 where tributary live loads change because of the occupancy (§ 1006.1). Exceptions exist where the demand does not increase materially (small percent increase). Height/area, means of egress and other parameters must be evaluated when the change moves the building to a higher hazard category; provisions in § 1011 (heights/areas, egress hazard categories, etc.) apply. Mechanical, plumbing and lighting requirements for the new occupancy must comply with the respective California Mechanical, Plumbing and Building Code provisions (§§ 1006, 1007, 1009, 1010, and § 1011).
Decision‑relevant table (quick reference)
| Decision factor | Typical values / trigger | Code reference |
|---|---|---|
| Approval required before change | Any change of occupancy or change within space that alters fire‑system thresholds | § 1001.2 — |
| Certificate of Occupancy required | Any change that results in a different occupancy classification | § 1001.3 — |
| Work scope to comply | All work connected to change must meet Chapters 6 and §§ 1002–1010; change of classification invokes §§ 1002–1011 | § 1001.2.1 / § 1001.2.2 — |
| Automatic sprinkler required | Where Chapter 9 would require sprinklers for the new occupancy (area/severity thresholds) | § 1011.2.1 — |
| Fire alarm/detection required | Where new occupancy or different Chapter 9 threshold requires it (follow Fire Code § 907) | § 1011.2.2 — |
| Structural evaluation | If live loads change or building assigned to higher risk category; exceptions for small increases | § 1006.1 / § 1006.2 / § 1006.3 — |
| Small-area exceptions | Certain structural/fire requirements may be waived where new occupancy area < 10% of building (see exceptions) | See § 1006 (exceptions) — |
| What CO shows | Permit #, address, owner, description, statement of compliance, occupancy & construction type, occupant load, sprinkler status, etc. | CBC administration (§ 110.2) — |
Exceptions & special cases
- Partial changes: where only a portion of a building changes occupancy classification and that portion is separated by required fire barriers or horizontal assemblies, Section 1011 (and related partial‑change provisions such as § 1001.2.2.1 or § 1302.1.2 where applicable) governs treatment of only the separated portion. file
- Limited-area exceptions: several provisions allow relief when the area of the new occupancy is a small portion of the building (commonly cited as less than 10% in several structural/fire provisions) — but the cumulative effect of repeated changes is considered. See the exceptions in §§ 1006.2–1006.3 and related sections.
- Change of use within same occupancy classification: this may still trigger required work if the change increases hazards (for example, change in activity that increases fire load or occupant load); § 1001.2.1 requires the work conform to the applicable requirements.
- State‑regulated occupancies and special methods: certain facilities (OSHPD, hospitals, state‑regulated occupancies) have additional or alternate compliance methods referenced in the code (see prescriptive/performance methods and Chapter 5A notes). If your project is state‑regulated, consult the agency‑specific provisions.
If a specific subsystem threshold (for example the exact area cutoff in Chapter 9 that triggers sprinklers) is needed, that specific Chapter 9 text is not reproduced here — you must check Chapter 9 or the local code official for the numeric thresholds. The Existing Building Code points you to that Chapter for the trigger but does not restate those numeric thresholds in § 1011.2.1.
Common mistakes
- Assuming no CO is needed because only the tenant or business is changing — a CO is required when the occupancy classification changes (§ 1001.3).
- Ignoring fire‑protection threshold changes — even a change within the same occupancy group can trigger sprinkler or alarm requirements if Chapter 9 thresholds change for that use (§ 1011.2 and § 1011.2.2).
- Failing to get code‑official approval before occupancy change — the code explicitly requires approval prior to making the change (§ 1001.2).
- Overlooking cumulative effects — repeated small changes can cumulatively trigger requirements (exceptions for small areas repeatedly note cumulative effect should be considered).
- Confusing zoning/land‑use approvals with the CO — the code official’s CO addresses building code compliance; zoning or business licensing may require separate permits (the CO does not substitute for other approvals). The CBC also makes clear a CO is not an approval to violate other laws.
Worked example
Scenario: A 20,000 ft² warehouse (Group S) contains a 2,000 ft² tenant space proposed to convert to retail sales (Group M). The proposed change is a change of occupancy classification (S → M) for a portion of the building.
Is a CO required? Yes — the change results in a different occupancy classification, so a certificate of occupancy must be issued once required work is met (§ 1001.3).
Code official approval: The owner/designer must present plans and obtain approval from the code official before putting the space into the new use (§ 1001.2).
Fire protection: Determine whether Chapter 9 requires sprinklers or a fire alarm for Group M in that building context. If Chapter 9 does require sprinklers for the new occupancy (or the change alters the Chapter 9 threshold), sprinklers must be installed in the area of change and in areas not separated by a firewall from the change (§ 1011.2.1). If Chapter 9 does not require sprinklers for this scenario, removal or omission may be permissible subject to approval (§ 1011.2.1.1). You must consult Chapter 9 or the local code official to determine the numeric trigger.
Area‑based exceptions: The new occupancy area is 2,000 / 20,000 = 10% of the building. Several change‑of‑occupancy structural and risk‑category exceptions use a 10% area threshold; because this change is exactly 10%, carefully check the exact exception language and consult the code official — the CBC notes the cumulative effect of occupancy changes over time must be considered (§ 1006 and related exceptions).
Structural/egress/other systems: Evaluate live‑load requirements (Section 1607) for the altered area (§ 1006.1), means of egress capacity for the occupant load change (§ 1011.5.3), plumbing fixture requirements if occupant load increases more than 20% for the story (§ 1009.1 exception), and mechanical/lighting as required (§§ 1009, 1010, 1008). The CO will not be issued until the code official finds compliance.
Summary of outcome in this scenario: expect to file plans, obtain code‑official review, provide whatever fire protection, egress, structural and plumbing/mechanical upgrades the code requires for the new occupancy (or document why exceptions apply), and receive a CO when the code official finds the requirements met (§§ 1001.2, 1001.3, and supporting sections).
Related provisions (quick pointers)
- § 1001.2 — Certificate of occupancy; approval required before change of occupancy.
- § 1001.3 — Certificate of occupancy required when change results in different occupancy classification.
- § 1001.2.1 / § 1001.2.2 — Change of use and change of occupancy classification: work scope and which sections apply.
- § 1011 (esp. § 1011.2) — Change of occupancy classification: required fire protection systems, means of egress and other conditions.
- § 1004.1 — Fire protection requirements where change of occupancy occurs.
- § 1005.1 — Means of egress requirements for change of occupancy.
- § 1006.1–1006.4 — Structural requirements (live loads, seismic, snow/wind) triggered by change of occupancy and associated exceptions.
- § 110.1 / § 110.2 (CBC administration) — Certificate of occupancy issuance and required contents of the CO.
- § 1009, § 1010 — Plumbing, mechanical and other systems impacted by occupancy changes.
Code references
Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:
CBC § 1001.1 High relevance — show source text
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10 CHANGE OF OCCUPANCY
User notes:
About this chapter : The purpose of this chapter is to provide regulations for the circumstances where an existing building is subject to a change of occupancy or a change of occupancy classification. A change of occupancy is not to be confused with a change of occupancy classification. The California Building Code defines different occupancy classifications in Chapter 3 and special occupancy requirements in Chapter 4. Within specific occupancy classifications there can be many different types of actual activities that can take place. For instance, a Group A-3 occupancy classification deals with a wide variation of different types of activities, including bowling alleys and courtrooms, indoor tennis courts and dance halls. When a facility changes use from, for example, a bowling alley to a dance hall, the occupancy classification remains A-3, but the different uses could lead to drastically different code requirements. Therefore, this chapter deals with the special circumstances that are associated with a change in the use of a building within the same occupancy classification as well as a change of occupancy classification.
SECTION 1001—GENERAL
1001.1 Scope. The provisions of this chapter shalle a change of occupancy occurs, as defined in Section 202.
1001.2 Certificate of occupancy. A change of occupancy or a change of occupancy within a space where there is a different fire protection system threshold requirement in Chapter 9 of th apply where current California Building Code than exists in the current building or space shall not be made to any structure without the approval of the code official. A certificate of occupancy shall be issued where it has been determined that the requirements for the change of occupancy have been met.
1001.2.1 Change of use. Any work undertaken in connection with a change in use shall conform to the applicable requirements for the work as classified in Chapter 6 and to the requirements of Sections 1002 through 1010.
1001.2.2 Change of occupancy classification. Where a building undergoes a change of occupancy classification, the provisions of Sections 1002 through 1011 shall apply.
1001.2.2.1 Partial change of occupancy. Where a portion of an existing building undergoes a change of occupancy classification, Section 1011 shall apply.
1001.3 Certificate of occupancy required. A certificate of occupancy shall be issued where a change of occupancy occurs that results in a different occupancy classification as determined by the California Building Code .
SECTION 1002—SPECIAL USE AND OCCUPANCY
1002.1 Compliance with the building code. Where an existing building or part of an existing building undergoes a change of occupancy to one of the special use or occupancy categories as described in Chapter 4 in the California Building Code, the building shall comply with all of the requirements of Chapter 4 of the California Building Code applicable to the special use or occupancy.
1002.2 Incidental uses. Where a portion of a building undergoes a change of occupancy to one of the incidental uses listed in Table 509.1 of the California Building Code, the incidental use shall comply with Section 509 of the California Building Code applicable to the incidental use.
SECTION 1003—BUILDING ELEMENTS AND MATERIALS
1003.1 General. Building elements and materials in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.
SECTION 1004—FIRE PROTECTION
CBC § 1001.2.1 High relevance — show source text
1001.2.1 Change of use. Any work undertaken in connection with a change in use shall conform to the applicable requirements for the work as classified in Chapter 6 and to the requirements of Sections 1002 through 1010.
1001.2.2 Change of occupancy classification. Where a building undergoes a change of occupancy classification, the provisions of Sections 1002 through 1011 shall apply.
1001.2.2.1 Partial change of occupancy. Where a portion of an existing building undergoes a change of occupancy classification, Section 1011 shall apply.
1001.3 Certificate of occupancy required. A certificate of occupancy shall be issued where a change of occupancy occurs that results in a different occupancy classification as determined by the California Building Code .
SECTION 1002—SPECIAL USE AND OCCUPANCY
1002.1 Compliance with the building code. Where an existing building or part of an existing building undergoes a change of occupancy to one of the special use or occupancy categories as described in Chapter 4 in the California Building Code, the building shall comply with all of the requirements of Chapter 4 of the California Building Code applicable to the special use or occupancy.
1002.2 Incidental uses. Where a portion of a building undergoes a change of occupancy to one of the incidental uses listed in Table 509.1 of the California Building Code, the incidental use shall comply with Section 509 of the California Building Code applicable to the incidental use.
SECTION 1003—BUILDING ELEMENTS AND MATERIALS
1003.1 General. Building elements and materials in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.
SECTION 1004—FIRE PROTECTION
1004.1 General. Fire protection requirements in Section 1011 shall apply where either of the following occur:
- A building or portion thereof undergoes a change of occupancy.
- A building or portion thereof undergoes a change of occupancy and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or portion thereof.
SECTION 1005—MEANS OF EGRESS
1005.1 General. Means of egress in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.
SECTION 1006—STRUCTURAL
[BS] 1006.1 Live loads. Structural elements carrying tributary live loads from an area with a change of occupancy shall satisfy the requirements of Section 1607 of the California Building Code . Design live loads for areas of new occupancy shall be based on Section 1607 of the California Building Code . Design live loads for other areas shall be permitted to use previously approved design live loads.
Exception: Structural elements whose demand-capacity ratio considering the change of occupancy is not more than 5 percent greater than the demand-capacity ratio based on previously approved live loads.
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CHANGE OF OCCUPANCY
[BS] 1006.2 Snow and wind loads. Where a change of occupancy results in a structure being assigned to a higher risk category, the structure shall satisfy the requirements of Sections 1608 and 1609 of the California Building Code for the new risk category.
CBC § 506.1 High 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:
- 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).
- 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 § 1.1 High relevance — show source text
Exception: The building need not be made to comply with Chapter 16 A of the California Building Code unless required by Section 506 A .5.
506 A .1.1 Change in function . A change in function shall require compliance with all the functional requirements for new construc- tion in the California Building Code, including requirements in California Building Code Section 1224. Compliance shall be only as necessary to meet the specific provisions and is not intended to require the entire building be brought into compliance.
Exception: Minimum room clearances, areas and dimensions may meet the requirements of the 2001 California Building Code for existing rooms re-used for a similar purpose, subject to the approval of OSHPD.
506 A .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 A .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 A .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:
- 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).
- 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.
506 A .5 Structural. Any building undergoing a change of occupancy shall satisfy the requirements of this section.
506 A .5.1 Live loads. Structural elements carrying tributary live loads from an area with a change of occupancy shall satisfy the requirements of Section 1607 A of the California Building Code . Design live loads for areas of new occupancy shall be based on Section 1607 A of the California Building Code . Design live loads for other areas shall be permitted to use previously approved design live loads.
Exception: Structural elements whose demand-capacity ratio considering the change of occupancy is not more than 5 percent greater than the demand-capacity ratio based on previously approved live loads need not comply with this section.
506 A .5.2 Snow and wind loads. Where a change of occupancy results in a structure being assigned to a higher risk category, the structure shall satisfy the requirements of Sections 1608 A and 1609 A of the California Building Code for the new risk category.
Exception: Where the area of the new occupancy is less than 10 percent of the building area, compliance with this section is not required. The cumulative effect of occupancy changes over time shall be considered.
CBC § 1302.1 High relevance — show source text
SECTION 1302—APPLICABILITY
1302.1 General. Existing buildings in which there is work involving additions, alterations or changes of occupancy shall be made to conform to the requirements of this chapter or the provisions of Chapters 6 through 12. The provisions of Sections 1302.1.1 through 1302.1.6 shall apply to existing occupancies that will continue to be, or are proposed to be, in Groups A, B, E, F, I-2, M, R and S. These provisions shall also apply to Group U occupancies where such occupancies are undergoing a change of occupancy or a partial change in occupancy with separations in accordance with Section 1302.1.2. These provisions shall not apply to buildings with occupancies in Group H, I-1, I-3 or I-4.
1302.1.1 Change in occupancy. Where an existing building is changed to a new occupancy classification and this section is applicable, the provisions of this section for the new occupancy shall be used to determine compliance with this code.
1302.1.2 Partial change in occupancy. Where a portion of the building is changed to a new occupancy classification and that portion is separated from the remainder of the building with fire barrier or horizontal assemblies having a fire-resistance rating as required by Table 508.4 of the International Building Code or Section R302 of the International Residential Code for the separate occupancies, or with approved compliance alternatives, the portion changed shall be made to conform to the provisions of this section. Only the portion separated shall be required to be evaluated for compliance.
Where a portion of the building is changed to a new occupancy classification and that portion is not separated from the remainder of the building with fire barriers or horizontal assemblies having a fire-resistance rating as required by Table 508.4 of the International Building Code or Section R302 of the International Residential Code for the separate occupancies, or with approved compliance alternatives, the provisions of this section which apply to each occupancy shall apply to the entire building. Where there are conflicting provisions, those requirements which secure the greater public safety shall apply to the entire building or structure.
1302.1.3 Additions. Additions to existing buildings shall comply with the requirements of the International Building Code or the International Residential Code for new construction. The combined height and area of the existing building and the new addition shall not exceed the height and area allowed by Chapter 5 of the International Building Code . Where a fire wall that complies with Section 706 of the International Building Code is provided between the addition and the existing building, the addition shall be considered a separate building. Where a new occupiable roof is added to a building or structure, the occupiable roof shall comply with the provisions of the International Building Code .
Exception: In-filling of floor openings and nonoccupiable appendages, such as elevator and exit stairway shafts, shall be permitted beyond that permitted by the International Building Code .
1302.1.4 Alterations. An existing building or portion thereof shall not be altered in such a manner that results in the building being less safe or sanitary than such building is currently.
Exception: Where the current level of safety or sanitation is proposed to be reduced, the portion altered shall conform to the requirements of the International Building Code .
1302.1.5 Escalators. Where escalators are provided in below-grade transportation stations, existing and new escalators shall be permitted to have a clear width of less than 32 inches (815 mm).
CBC § 109.3.11 High relevance — show source text
[A] 109.3.11 Final inspection. The final inspection shall be made after work required by the building permit is completed.
[A] 109.4 Inspection agencies. The code official is authorized to accept reports of approved inspection agencies, provided that such agencies satisfy the requirements as to qualifications and reliability.
[A] 109.5 Inspection requests. It shall be the duty of the holder of the building permit or their duly authorized agent to notify the code official when work is ready for inspection. It shall be the duty of the permit holder to provide access to and means for any inspections of such work that are required by this code.
[A] 109.6 Approval required. Work shall not be done beyond the point indicated in each successive inspection without first obtaining the approval of the code official. The code official, on notification, shall make the requested inspections and shall either indicate the portion of the construction that is satisfactory as completed or shall notify the permit holder or an agent of the permit holder
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ADMINISTRATION
wherein the same fails to comply with this code. Any portions that do not comply shall be corrected and such portion shall not be covered or concealed until authorized by the code official.
SECTION 110—CERTIFICATE OF OCCUPANCY
[A] 110.1 Change of occupancy. A structure shall not be used or occupied in whole or in part, and a change of occupancy of a structure or portion thereof shall not be made until the code official has issued a certificate of occupancy therefor as provided herein. Issuance of a certificate of occupancy shall not be construed as an approval of a violation of the provisions of this code or of other ordinances of the jurisdiction. Certificates presuming to give authority to violate or cancel the provisions of this code or other ordinances of the jurisdiction shall not be valid.
Exception: Certificates of occupancy are not required for work exempt from permits in accordance with Section 105.2.
[A] 110.2 Certificate issued. After the code official inspects the structure and does not find violations of the provisions of this code or other laws that are enforced by the department, the code official shall issue a certificate of occupancy that contains the following:
The permit number.
The address of the structure.
The name and address of the owner or the owner’s authorized agent.
A description of that portion of the structure for which the certificate is issued.
A statement that the described portion of the structure has been inspected for compliance with the requirements of this code for the occupancy and division of occupancy and the use for which the proposed occupancy is classified.
The name of the code official.
The edition of the code under which the permit was issued.
The use and occupancy in accordance with the provisions of the California Building Code .
The type of construction as defined in the California Building Code .
The design occupant load and any impact the alteration has on the design occupant load of the area not within the scope of the work.
Where an automatic sprinkler system is provided, and whether an automatic sprinkler system is required.
Any special stipulations and conditions of the building permit.
CBC § 1007.1 High relevance — show source text
3 Exception 3|X|||||||||||||||||||||||| |1007||||†|†|||||||||||||||||||| |1007.1|||X|||||||||||||||||||||| |1009.2 – 1009.4||||†|†|||||||||||||||||||| |1011.2.1|||X|||||||||||||||||||||| |1011.2.2|||X|||||||||||||||||||||| |1011.4||||†|†|||||||||||||||||||| |1011.5.1|||X|||||||||||||||||||||| |1011.5.1 Exception 8||||†|†|||||||||||||||||||| |Table 1011.5|||X|||||||||||||||||||||| |1011.5.2|||X|||||||||||||||||||||| |1011.5.2 Exception 2||||†|†|||||||||||||||||||| |1011.5.4|||X|||||||||||||||||||||| |1011.5.5|||X|||||||||||||||||||||| |1011.6.1 Exception 1||||†|†|||||||||||||||||||| |1011.7.1 Exception||||†|†|||||||||||||||||||| |1011.8.2|||X||||||||||||||||||||||
The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
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10-2 2025 CALIFORNIA EXISTING BUILDING CODE
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10 CHANGE OF OCCUPANCY
User notes:
About this chapter : The purpose of this chapter is to provide regulations for the circumstances where an existing building is subject to a change of occupancy or a change of occupancy classification. A change of occupancy is not to be confused with a change of occupancy classification. The California Building Code defines different occupancy classifications in Chapter 3 and special occupancy requirements in Chapter 4. Within specific occupancy classifications there can be many different types of actual activities that can take place. For instance, a Group A-3 occupancy classification deals with a wide variation of different types of activities, including bowling alleys and courtrooms, indoor tennis courts and dance halls. When a facility changes use from, for example, a bowling alley to a dance hall, the occupancy classification remains A-3, but the different uses could lead to drastically different code requirements. Therefore, this chapter deals with the special circumstances that are associated with a change in the use of a building within the same occupancy classification as well as a change of occupancy classification.
SECTION 1001—GENERAL
1001.1 Scope. The provisions of this chapter shalle a change of occupancy occurs, as defined in Section 202.
1001.2 Certificate of occupancy. A change of occupancy or a change of occupancy within a space where there is a different fire protection system threshold requirement in Chapter 9 of th apply where current California Building Code than exists in the current building or space shall not be made to any structure without the approval of the code official. A certificate of occupancy shall be issued where it has been determined that the requirements for the change of occupancy have been met.
CBC § 1.10.1 High relevance — show source text
Chapter 5A Prescriptive Compliance Method.
Chapter 5A provides details for the prescriptive compliance method for alteration, addition and change of occupancy of existing build- ings and structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
Chapter 6 Classification of Work.
Chapter 6 provides an overview of the Work Area Method and defines the different classifications of work including alterations, change of occupancy, additions and historic buildings. Detailed requirements for all of these are given in subsequent Chapters 7 through 11.
Chapter 7 Alterations—Level 1.
Chapter 7 provides the technical requirements for those existing buildings that undergo Level 1 alterations as described in Section 602, which includes replacement or covering of existing materials, elements, equipment or fixtures using new materials for the same purpose. This chapter is distinguished from Chapters 8 and 9 by only involving replacement of building components with new components with no reconfiguration of space.
Chapter 8 Alterations—Level 2.
A Level 2 alteration is an alteration involving space reconfiguration that could be up to and including 50 percent of the area of the building or addition of a new building system. Level 2 alterations also include the extension or addition of any system or equipment. The purpose of Chapter 8 is to provide detailed requirements and provisions to identify the required improvements in the existing building elements, means of egress, fire protection, structural systems, energy efficiency, and other building systems include electrical, mechanical and plumbing when a building is being altered.
Chapter 9 Alterations—Level 3.
Chapter 9 provides the technical requirements for those existing buildings that undergo Level 3 alterations. Level 3 alterations are those involving alterations that cover 50 percent of the aggregate area of the building. Under certain situations, this chapter also intends to improve the safety of certain building features beyond the work area and in other parts of the building where no alteration work might be taking place.
Chapter 10 Change of Occupancy.
The purpose of Chapter 10 is to address existing buildings that are subject to a change of occupancy. This chapter is an assembly of requirements to upgrade safety without having to comply fully as a new building. A change of occupancy classification is considered a change of occupancy, however, it will involve a higher level of regulation since the use of the building has made a more significant change.
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Chapter 11 Additions.
Chapter 11 provides the requirements for additions, which are considered new construction. The requirements focus on safely integrating the addition with the existing building. This includes issues such as limiting the overall height and area of the building where the addition is not separated by a fire wall.
Chapter 12 Historic Buildings —Reserved
Chapter 12 is not adopted by the State of California. Historic buildings and structures shall comply with Part 8, Title 24, California Code of Regulations.
Chapter 13 Performance Compliance Methods.
Chapter 13 allows for existing buildings to be evaluated to show that alterations or a change of occupancy, while not meeting new construction requirements, will provide a level of safety to demonstrate compliance. Provisions are based on a numerical scoring system involving 21 safety parameters where, when evaluated, such buildings must meet a minimum overall safety score.
CBC § 1006.3 High relevance — show source text
Exception: Where the area of the new occupancy is less than 10 percent of the building area. The cumulative effect of occupancy changes over time shall be considered.
[BS] 1006.3 Seismic loads. Where a change of occupancy results in a building being assigned to a higher risk category, or where the change is from a Group S or Group U occupancy to any occupancy other than Group S or Group U, the lateral force-resisting system of the building shall comply with Section 304.3.1 for the new risk category. Where a change of occupancy results in a building being assigned to Risk Category IV and Seismic Design Category D or F, nonstructural components serving any portion of the building changed to Risk Category IV shall comply with the requirements of Section 1613 of the California Building Code or shall comply with ASCE 41 using an objective of operational nonstructural performance with the BSE-1N earthquake hazard level.
Exceptions:
Where a change of use results in a building being reclassified from Risk Category I or II to Risk Category III and the seismic coefficient, S DS, is less than 0.33, compliance with this section is not required.
Where the area of the new occupancy is less than 10 percent of the building area, the occupancy is not changing from a Group S or Group U occupancy, and the new occupancy is not assigned to Risk Category IV, compliance with this section is not required. The cumulative effect of occupancy changes over time shall be considered.
Reserved.
Where the change is from a Group S or Group U occupancy and there is no change of risk category, compliance with Section 304.3.2 shall be permitted.
[BS] 1006.4 Access to Risk Category IV. Any structure that provides operational access to an adjacent structure assigned to Risk Category IV as the result of a change of occupancy shall itself comply with Sections 1608 and 1609 of the California Building Code and Section 304.3.1 of this code. Where operational access to Risk Category IV is less than 10 feet (3048 mm) from either an interior lot line or from another structure, access protection from potential falling debris shall be provided.
SECTION 1007—ELECTRICAL
1007.1 Special occupancies. Where the occupancy of an existing building or part of an existing building is changed to one of the following special occupancies as described in the California Electrical Code, the electrical wiring and equipment of the building or portion thereof that contains the proposed occupancy shall comply with the applicable requirements of the California Electrical Code :
Hazardous locations.
Commercial garages, repair and storage.
Aircraft hangars.
Gasoline dispensing and service stations.
Bulk storage plants.
Spray application, dipping and coating processes.
Reserved.
Places of assembly.
Theaters, audience areas of motion picture and television studios, and similar locations.
Motion picture and television studios and similar locations.
Motion picture projectors.
Agricultural buildings.
1007.2 Unsafe conditions. Where the occupancy of an existing building or part of an existing building is changed, all unsafe conditions shall be corrected without requiring that all parts of the electrical system comply with the California Electrical Code .
1007.3 Service upgrade. Where the occupancy of an existing building or part of an existing building is changed, electrical service shall be upgraded to meet the requirements of the California Electrical Code for the new occupancy.
CBC § 1011.2.1.1 High relevance — show source text
1011.2.1.1 Nonrequired automatic sprinkler systems. The code official is authorized to permit the removal of an existing automatic sprinkler system where all of the following conditions exist:
- The system is not required for new construction.
- Portions of the system that are exposed to the public are removed.
- The system was not installed as part of any special construction features, including fire-resistance-rated assemblies and smoke-resistive assemblies, conditions of occupancy, means of egress conditions, fire code deficiencies, approved modifications or approved alternative materials, design and methods of construction, and equipment applying to the building.
1011.2.1.1.1 Approval. Plans, investigation and evaluation reports, and other data shall be submitted documenting compliance with Section 1011.2.1.1 for review and approval in support of a determination authorizing the removal of the automatic sprinkler system by the code official.
1011.2.2 Fire alarm and detection system. Where a change in occupancy classification occurs or where there is a change of occupancy within a space where there is a different fire protection system threshold requirement in Chapter 9 of the current Cali- fornia Building Code than exists in the current building or space that requires a fire alarm and detection system to be provided based on the new occupancy, such system shall be in accordance with Chapter 11 and Section 907 of the California Fire Code.
1011.3 Interior finish. In areas of the building undergoing the change of occupancy classification, the interior finish of walls and ceilings shall comply with the requirements of the California Building Code for the new occupancy classification.
1011.4 Enhanced classroom acoustics. In Group E occupancies, where the work area is a Level 3 alteration, enhanced classroom acoustics shall be provided in all classrooms with a volume of 20,000 cubic feet (565 m [3] ) or less. Enhanced classroom acoustics shall comply with the reverberation time in Section 808 of ICC A117.1.
2025 CALIFORNIA EXISTING BUILDING CODE 10-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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CHANGE OF OCCUPANCY
1011.5 Means of egress, general. Hazard categories in regard to life safety and means of egress shall be in accordance with Table 1011.5.
TABLE 1011.5—MEANS OF EGRESS HAZARD CATEGORIES Col2 RELATIVE HAZARD OCCUPANCY CLASSIFICATIONS 1 (Highest Hazard) H (Not Allowed) 2 I-2; I-3; I-4_(Not Allowed)_ 3 A; E; M; R-1; R-2; R-4 4 B; F-1; R-3; R-4, S-1 5 (Lowest Hazard) F-2; S-2; U 1011.5.1 Means of egress for change to a higher-hazard category. Where a change of occupancy classification is made to a higher-hazard category (lower number) as shown in Table 1011.5, the means of egress shall comply with the requirements of Chapter 10 of the California Building Code .
Exceptions:
- Stairways shall be enclosed in compliance with the applicable provisions of Section 903.1.
CBC § 1004.1 Medium relevance — show source text
SECTION 1004—FIRE PROTECTION
1004.1 General. Fire protection requirements in Section 1011 shall apply where either of the following occur:
- A building or portion thereof undergoes a change of occupancy.
- A building or portion thereof undergoes a change of occupancy and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or portion thereof.
SECTION 1005—MEANS OF EGRESS
1005.1 General. Means of egress in portions of buildings undergoing a change of occupancy classification shall comply with Section 1011.
SECTION 1006—STRUCTURAL
[BS] 1006.1 Live loads. Structural elements carrying tributary live loads from an area with a change of occupancy shall satisfy the requirements of Section 1607 of the California Building Code . Design live loads for areas of new occupancy shall be based on Section 1607 of the California Building Code . Design live loads for other areas shall be permitted to use previously approved design live loads.
Exception: Structural elements whose demand-capacity ratio considering the change of occupancy is not more than 5 percent greater than the demand-capacity ratio based on previously approved live loads.
2025 CALIFORNIA EXISTING BUILDING CODE 10-3
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CHANGE OF OCCUPANCY
[BS] 1006.2 Snow and wind loads. Where a change of occupancy results in a structure being assigned to a higher risk category, the structure shall satisfy the requirements of Sections 1608 and 1609 of the California Building Code for the new risk category.
Exception: Where the area of the new occupancy is less than 10 percent of the building area. The cumulative effect of occupancy changes over time shall be considered.
[BS] 1006.3 Seismic loads. Where a change of occupancy results in a building being assigned to a higher risk category, or where the change is from a Group S or Group U occupancy to any occupancy other than Group S or Group U, the lateral force-resisting system of the building shall comply with Section 304.3.1 for the new risk category. Where a change of occupancy results in a building being assigned to Risk Category IV and Seismic Design Category D or F, nonstructural components serving any portion of the building changed to Risk Category IV shall comply with the requirements of Section 1613 of the California Building Code or shall comply with ASCE 41 using an objective of operational nonstructural performance with the BSE-1N earthquake hazard level.
Exceptions:
Where a change of use results in a building being reclassified from Risk Category I or II to Risk Category III and the seismic coefficient, S DS, is less than 0.33, compliance with this section is not required.
Where the area of the new occupancy is less than 10 percent of the building area, the occupancy is not changing from a Group S or Group U occupancy, and the new occupancy is not assigned to Risk Category IV, compliance with this section is not required. The cumulative effect of occupancy changes over time shall be considered.
Reserved.
Where the change is from a Group S or Group U occupancy and there is no change of risk category, compliance with Section 304.3.2 shall be permitted.
CBC § 1009.3 Medium relevance — show source text
1009.3 Interceptor required. If the new occupancy will produce grease or oil-laden wastes, interceptors shall be provided as required in the California Plumbing Code .
1009.4 Chemical wastes. If the new occupancy will produce chemical wastes, the following shall apply:
- If the existing piping is not compatible with the chemical waste, the waste shall be neutralized prior to entering the drainage system or the piping shall be changed to a compatible material.
- Chemical waste shall not discharge to a public sewer system without the approval of the sewage authority.
SECTION 1010—OTHER REQUIREMENTS
1010.1 Light and ventilation. Light and ventilation shall comply with the requirements of the California Building Code for the new
occupancy.
SECTION 1011—CHANGE OF OCCUPANCY CLASSIFICATION
1011.1 General. The provisions of this section shall apply to buildings or portions thereof undergoing a change of occupancy classification. This includes a change of occupancy classification within a group as well as a change of occupancy classification from one group to a different group. The provisions of this section shall also apply where there is a change of occupancy within a building or portion thereof and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space. Such buildings shall also comply with Sections 1002 through 1010 of this code.
1011.2 Fire protection systems. Fire protection systems shall be provided in accordance with Sections 1011.2.1 and 1011.2.2.
1011.2.1 Automatic sprinkler system. The installation of an automatic sprinkler system shall be required where there is a change of occupancy classification and Chapter 9 of the current California Building Code requires an automatic sprinkler system based on the new occupancy or where there is a change of occupancy within the space where there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space . The installation of the automatic sprinkler system shall be required within the area of the change of occupancy and areas of the building not separated by a fire wall from the change of occupancy.
1011.2.1.1 Nonrequired automatic sprinkler systems. The code official is authorized to permit the removal of an existing automatic sprinkler system where all of the following conditions exist:
- The system is not required for new construction.
- Portions of the system that are exposed to the public are removed.
- The system was not installed as part of any special construction features, including fire-resistance-rated assemblies and smoke-resistive assemblies, conditions of occupancy, means of egress conditions, fire code deficiencies, approved modifications or approved alternative materials, design and methods of construction, and equipment applying to the building.
1011.2.1.1.1 Approval. Plans, investigation and evaluation reports, and other data shall be submitted documenting compliance with Section 1011.2.1.1 for review and approval in support of a determination authorizing the removal of the automatic sprinkler system by the code official.
1011.2.2 Fire alarm and detection system. Where a change in occupancy classification occurs or where there is a change of occupancy within a space where there is a different fire protection system threshold requirement in Chapter 9 of the current Cali- fornia Building Code than exists in the current building or space that requires a fire alarm and detection system to be provided based on the new occupancy, such system shall be in accordance with Chapter 11 and Section 907 of the California Fire Code.
Frequently asked questions
Do I always need a building permit to change occupancy?
Not necessarily—some minor work exempt from permits (see CBC permit exemptions) may not require a CO; however, any change that results in a different occupancy classification requires a CO and approval by the code official (§ 1001.3 and CBC administration). file
If I only change the business but not the classification, do I need approval?
If the occupancy classification does not change you may still need to comply with applicable requirements for the new use (for example, alterations required under § 1001.2.1) and obtain the code official’s approval where special provisions apply.
Who issues the Certificate of Occupancy?
The code official (building official) issues the CO after inspection and determination of compliance; the CO documents occupancy, construction type, occupant load, sprinkler status and other items (§ 110.2).
Does a CO cover zoning or business licensing?
No. A CO demonstrates compliance with the building code for occupancy and use; it does not replace zoning, land‑use or business licensing approvals — those remain separate. The CBC also states a CO does not validate violations of other laws.
What if Chapter 9 requires sprinklers but the building already has some sprinklers I want to remove?
The code official may permit removal of a nonrequired automatic sprinkler system only where the conditions and documentation in § 1011.2.1.1 (and its approval subsection) are satisfied. Submit plans and evaluation reports for review.
More in California Building Code
- Administration & Permits
- Energy Efficiency
- Existing Buildings
- Occupancy Classification & Use
- Hazardous Materials & Occupancies
- Types of Construction
- Fire-Resistance & Fire Safety
- Interior Finishes
- Means of Egress
- Accessibility
- Exterior Walls
- Roofing & Roof Assemblies
- Structural Design
- Special Inspections & Tests
- Foundations & Soils
- Concrete
- Masonry
- Steel
- Wood
- Elevators & Conveying Systems
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