CHBC · California Historical Building Code
When may a historical occupancy be continued without full regular-code upgrades?
If your building is an officially qualified historic property and its historic use complied with the construction rules when it was built, the CHBC generally lets you keep that same use (even after long vacancy) so long as it does not create a distinct life‑safety hazard; you will usually only need to fix unsafe items or meet specific mitigation (like sprinklers or a life‑safety evaluation) rather than do a full regular‑code upgrade.
Last reviewed: July 6, 2026
What the code requires — 2–4 sentences
A qualified historical building or property may continue its existing use or occupancy without being forced to meet full new‑construction (regular code) upgrades so long as the use “conformed to the code or to the standards of construction in effect at the time of construction” and the continued use “does not constitute a distinct hazard to life safety.” This authorization is the CHBC rule for continued use in § 8-102.1.4 and is implemented alongside the allowance that an existing use may be continued regardless of periods of vacancy so long as the building otherwise conforms to applicable CHBC requirements in § 8-302.1 .
A historical building can keep using its historic occupancy (even after long vacancy) if it originally complied with the code of its day and it is not a distinct life‑safety hazard — the CHBC lets the historic use continue instead of forcing a full upgrade. (See § 8-102.1.4 and § 8-302.1.)
Requirements in detail
Key defined terms to know (first use bolded)
- Qualified historical building or property — buildings or properties designated or eligible as historic (definition and scope) — see § 8-2 definitions and CHBC introductory material.
- Existing use / existing occupancy — the use or character of occupancy that is already in place; the CHBC expressly permits continuation of that use under § 8-302.1.
- Distinct hazard / life‑safety hazard — conditions that create a special, unacceptable risk to occupant safety; the continued use must not “constitute a distinct hazard” per § 8-102.1.4.
What the two controlling sections say (plain intent)
- § 8-102.1.4 (Continued use): If the historical use matched the code or construction standards at time of original construction and does not present a distinct life‑safety hazard, the historical use may continue without being forced to conform to the regular (new‑construction) code.
- § 8-302.1 (Existing use): The existing use or character of occupancy may be permitted to continue — even after long vacancy or interim uses — provided the building otherwise conforms to applicable CHBC requirements.
Decision‑relevant dimensions (quick table)
| Decision factor | Values / trigger | Effect (may or may not allow continued historical occupancy) | Code reference |
|---|---|---|---|
| Is the building a qualified historical building or property? | Yes / No | CHBC only applies if building is qualified; otherwise regular code controls | § 8-102.1 |
| Did the historic use “conform to the code or standards in effect at the time of construction”? | Yes / No / Unknown | If Yes, continued use is permitted subject to CHBC; if No, enforcing agency will evaluate hazard and required corrections | § 8-102.1.4 |
| Does the continued use “constitute a distinct hazard to life safety”? | Yes / No | If Yes, continued use is not permitted without remediation; if No, continuation is allowed under CHBC | § 8-102.1.4 |
| Has the building been declared unsafe under the regular code? | Yes / No | If unsafe, CHBC applies to the work necessary to correct the unsafe conditions only — not to full code compliance across entire building | § 8-102.1.5 |
| Is the owner undertaking work (alteration, addition, relocation)? | None / Repair / Alteration / Addition | Alterations/additions must follow CHBC rules; nonhistorical additions may need to meet regular code (see § 8-102.1.1) | § 8-102.1.1, § 8-102.1.6 |
| Size / area / height thresholds that matter | One‑story max 15,000 sq ft; high‑rise stories > 75 ft | These CHBC area/height rules may limit or allow continuation without full upgrades (exceptions exist with sprinklers or alarms) | § 8-302.4, § 8-302.5.1 |
How the evaluating authority applies these rules
- The enforcing agency first confirms the building is a qualified historical building and that the owner elects to use CHBC procedures. § 8-102.1 requires application of CHBC when elected.
- The agency checks whether the existing use historically conformed to the building standards at the time of construction. If conformity existed and no distinct hazard is present, the historical use may continue under § 8-102.1.4 and § 8-302.1.
- If an unsafe condition is formally found under the regular code, only the work necessary to correct those unsafe conditions need be completed (CHBC governs the scope of remediation), rather than forcing full regular‑code upgrades everywhere. § 8-102.1.5 explains this approach.
Exceptions & special cases
- Unsafe buildings: When a building is determined unsafe under the regular code, the CHBC governs remediation work and limits the required scope to correcting the unsafe conditions — it does not require bringing the entire building to full regular‑code compliance. See § 8-102.1.5.
- Work‑triggered upgrades: If you undertake an alteration, addition, or relocation, CHBC controls the required compliance for that work; however, nonhistorical additions must conform to the regular code (see § 8-102.1.1 and § 8-704).
- Accessibility and distinct mandates: Some mandated items (accessible path elements, mandated life‑safety corrections) may require specific action even under CHBC — see § 8-102.1.6 for limits on additional work and Chapter 8‑6 (accessibility) for equivalent facilitation provisions.
- Fire protection tradeoffs: CHBC allows alternatives (sprinklers, life‑safety evaluations) instead of one‑hour fire‑resistive upgrades — e.g., § 8-402.2 lists that one‑hour construction upgrades are not required when there is (1) sprinkler system throughout, (2) approved life‑safety evaluation, or (3) other alternatives approved by the enforcing agency.
- Size/area exceptions: One‑story historical buildings are limited to 15,000 sq ft unless exceptions (e.g., sprinklers) apply — see § 8-302.4.
Common mistakes
- Assuming CHBC automatically allows any continued use. CHBC allows continuation only when the historic use conformed at the time of construction and does not present a distinct hazard — refer to § 8-102.1.4 and § 8-302.1.
- Ignoring work triggers. Beginning repairs, alterations or additions can change the scope of required compliance; nonhistorical additions may require regular‑code conformity. Check § 8-102.1.1, § 8-704 and § 8-102.1.6.
- Treating “vacancy” as a loss of right to continue historic use. CHBC explicitly permits continuation of an existing use “regardless of any period of time in which it may have remained unoccupied,” per § 8-302.1 — vacancy alone is not dispositive.
- Overlooking mandated corrections when a distinct hazard exists. If the continued use does create a distinct hazard, the enforcing agency will require correction; the CHBC does not shield life‑safety remediation. See § 8-102.1.4 and § 8-102.1.5.
Worked example — concrete scenario
Scenario: A 1905 three‑story theater (assembly use) was built to the standards of 1905. It has been vacant for 12 years. The owner wants to reopen it to performances without doing a full seismic or new‑construction code upgrade.
Step 1 — Is it a qualified historical building?
- Assume yes (local register). CHBC applies when elected by the owner (§ 8-102.1).
Step 2 — Did the historic use conform when built?
- Owner produces old permits / documentation showing the theater met the 1905 construction standards. That supports CHBC continued‑use eligibility under § 8-102.1.4.
Step 3 — Does reopening create a distinct hazard?
- Inspectors evaluate life‑safety systems. Suppose they find fire egress is historically narrow but overall structure is sound and no immediate “distinct hazard” is found. In that case, reopening as the original assembly use is allowed under § 8-102.1.4 and § 8-302.1 without forcing full regular‑code upgrades.
Step 4 — Are there conditional requirements?
- The enforcing agency may require targeted corrections for any unsafe elements (e.g., a single unsafe stair) — work limited to correcting unsafe conditions per § 8-102.1.5. If an agency requires a building‑wide life‑safety evaluation or sprinklers to mitigate hazards, those are the specific remedies rather than a full new‑construction upgrade.
Numeric example: If the theater’s main floor is 12,000 sq ft, it sits under the 15,000 sq ft one‑story CHBC cap in § 8-302.4, so no area-triggered additional separation is required; if it were to exceed 15,000 sq ft, sprinklering or other exception routes would need to be considered.
Related provisions (quick list)
- § 8-102.1 — Application of the CHBC (use by enforcing agencies; when CHBC applies).
- § 8-102.1.5 — Unsafe buildings: scope of CHBC remediation when unsafe conditions are found.
- § 8-102.1.6 — Limits on additional work required by regular code beyond the work undertaken; accessibility & distinct hazards caveats.
- § 8-302.2 — Change in occupancy rules when returning to historic use (change of occupancy handled in Chapter 8‑3).
- § 8-302.4 — Maximum floor area rules and exceptions (15,000 sq ft one‑story cap).
- § 8-302.3 — Occupancy separations and sprinkler tradeoffs (see cross‑reference to § 8-410).
- § 8-402.2 — Fire‑resistive construction exceptions when sprinklers / life‑safety evaluations are provided.
- Chapter 8‑7 (e.g., § 8-703) — Structural survey requirements when structural capacity is evaluated under CHBC.
- Chapter 8‑6 (e.g., § 8-604) — Accessibility: equivalent facilitation and case‑by‑case alternatives for historic properties.
Code references
Grounded in the retrieved California Historical Building Code — click a citation to read the verbatim passage:
CHBC § 8-102.1.1 High relevance — show source text
- State agencies. All state agencies shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, rehabilitation, safety, relocation, reconstruction or continued use of qualified historical buildings or properties.
8-102.1.1 Additions, alterations and repairs. It is the intent of the CHBC to allow nonhistorical expansion or addition to a qualified historical building or property, provided nonhistorical additions shall conform to the requirements of the regular code (as defined in Chapter 8-2).
8-102.1.2 Relocation. Relocated qualified historical buildings or properties shall be sited to comply with the regular code or with the solutions listed in the CHBC. Nonhistorical new construction related to relocation shall comply with the regular code. Reconstruction and restoration related to relocation is permitted to comply with the provisions in the CHBC.
8-102.1.3 Change of occupancy. For change of use or occupancy, see Chapter 8-3, Use and Occupancy.
8-102.1.4 Continued use. Qualified historical buildings or properties may have their existing use or occupancy continued if such use or occupancy conformed to the code or to the standards of construction in effect at the time of construction, and such use or occupancy does not constitute a distinct hazard to life safety as defined in the CHBC.
8-102.1.5 Unsafe buildings or properties. When a qualified historical building or property is determined to be unsafe as defined in the regular code, the requirements of the CHBC are applicable to the work necessary to correct the unsafe conditions. Work to remediate the buildings or properties need only address the correction of the unsafe conditions, and it shall not be required to bring the entire qualified historical building or property into compliance with regular code.
8-102.1.6 Additional work. Qualified historical buildings or properties shall not be subject to additional work required by the regular code, regulation or ordinance beyond that required to complete the work undertaken. Certain exceptions for accessibility and for distinct hazards exist by mandate and may require specific action, within the parameters of the CHBC.
SECTION 8-103 — ORGANIZATION AND ENFORCEMENT
8-103.1 Authority. The state or local enforcing agency, pursuant to authority provided under Section 18954 of the Health and Safety Code, shall administer and enforce the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, reconstruction, rehabilitation, relocation or continued use of a qualified historical building or property.
8-103.2 State enforcement. All state agencies pursuant to authority provided under Section 18954 and Section 18961 of the Health and Safety Code shall administer and enforce the CHBC with respect to qualified historical buildings or properties under their respective jurisdiction.
8-103.3 Liability. Prevailing law regarding immunity of building officials is unaffected by the use and enforcement of the CHBC.
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ADMINISTRATION
SECTION 8-104 — REVIEW AND APPEALS
8-104.1 State Historical Building Safety Board (SHBSB or Board). In order to provide for interpretation of the provisions of the CHBC and to hear appeals, the SHBSB shall act as an appeal and review body to state and local agencies or any affected party.
**8-104.2 SHBSB review.
CHBC § 8-3 High relevance — show source text
This shall include historical buildings or properties on, or determined eligible for, national, state or local historical registers or inventories, such as the National Register of Historic Places, California Register of Historical Resources, State Historical Landmarks, State Points of Historical Interest, and city or county registers, inventories or surveys of historical or architecturally significant sites, places or landmarks.
RECONSTRUCTION. The act or process of depicting, by means of new construction, the form, features and detailing of a nonsurviving site, landscape, building, property or object for the purpose of replicating its appearance at a specific period of time.
REGULAR CODE. The adopted regulations that govern the design and construction or alteration of nonhistorical buildings and properties within the jurisdiction of the enforcing agency.
REHABILITATION. The act or process of making possible a compatible use for qualified historical building or property through repair, alterations and additions while preserving those portions or features which convey its qualified historical, cultural or architectural values.
RELOCATION. The act or process of moving any qualified historical building or property or a portion of a qualified historical building or property to a new site, or a different location on the same site.
REPAIR. Renewal, reconstruction or renovation of any portion of an existing property, site or building for the purpose of its continued use.
RESTORATION. The act or process of accurately depicting the form, features and character of a qualified building or property as it appeared at a particular period of time by the means of the removal of features from other periods in its history and reconstruction of missing features from the restoration period. The limited and sensitive upgrading of mechanical, electrical and plumbing systems and other code-required work to make properties functional is appropriate within a restoration project.
STRUCTURE. That which is built or constructed, an edifice or a building of any kind, or any piece of work artificially built up or composed of parts joined together in some definite manner.
TREATMENT. An act of work to carry out preservation, restoration, stabilization, rehabilitation or reconstruction.
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8-3 USE AND OCCUPANCY
SECTION 8-301 — PURPOSE AND SCOPE
8-301.1 Purpose. The purpose of the CHBC is to provide regulations for the determination of occupancy classifications and conditions of use for qualified historical buildings or properties.
8-301.2 Scope. Every qualified historical building or property for which a permit or approval has been requested shall be classified prior to permit issuance according to its use or the character of its occupancy in accordance with the regular code and applicable provisions of this chapter.
SECTION 8-302 — GENERAL
8-302.1 Existing use. The use or character of occupancy of a qualified historical building or property, or portion thereof, shall be permitted to continue in use regardless of any period of time in which it may have remained unoccupied or in other uses, provided such building or property otherwise conforms to all applicable requirements of the CHBC.
8-302.2 Change in occupancy. The use or character of the occupancy of a qualified historical building or property may be changed from or returned to its historical use or character, provided the qualified historical building or property conforms to the requirements applicable to the new use or character of occupancy as set forth in the CHBC. Such change in occupancy shall not mandate conformance with new construction requirements as set forth in regular code.
CHBC § 8-101.1 High relevance — show source text
8-101.1 Title. These regulations shall be known as the California Historical Building Code and will be referred to herein as “the CHBC.”
8-101.2 Purpose. The purpose of the CHBC is to provide regulations for the preservation, restoration, rehabilitation, relocation or reconstruction of buildings or properties designated as qualified historical buildings or properties (as defined in Chapter 8-2). The CHBC is intended to provide solutions for the preservation of qualified historical buildings or properties, to promote sustainability, to provide access for persons with disabilities, to provide a cost-effective approach to preservation, and to provide for the reasonable safety of the occupants or users. The CHBC requires enforcing agencies to accept solutions that are reasonably equivalent to the regular code (as defined in Chapter 8-2) when dealing with qualified historical buildings or properties.
8-101.3 Intent. The intent of the CHBC is to facilitate the preservation and continuing use of qualified historical buildings or properties while providing reasonable safety for the building occupants and access for persons with disabilities.
SECTION 8-102 — APPLICATION
8-102.1 Application. The CHBC is applicable to all issues regarding code compliance for qualified historical buildings or properties. The CHBC may be used in conjunction with the regular code to provide solutions to facilitate the preservation of qualified historical buildings or properties. The CHBC shall be used by any agency with jurisdiction and whenever compliance with the code is required for qualified historical buildings or properties.
- State or local enforcing agency. The state or local enforcing agency shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, reconstruction, rehabilitation, relocation or continued use of a qualified historical building or property when so elected by the private property owner.
- State agencies. All state agencies shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, rehabilitation, safety, relocation, reconstruction or continued use of qualified historical buildings or properties.
8-102.1.1 Additions, alterations and repairs. It is the intent of the CHBC to allow nonhistorical expansion or addition to a qualified historical building or property, provided nonhistorical additions shall conform to the requirements of the regular code (as defined in Chapter 8-2).
8-102.1.2 Relocation. Relocated qualified historical buildings or properties shall be sited to comply with the regular code or with the solutions listed in the CHBC. Nonhistorical new construction related to relocation shall comply with the regular code. Reconstruction and restoration related to relocation is permitted to comply with the provisions in the CHBC.
8-102.1.3 Change of occupancy. For change of use or occupancy, see Chapter 8-3, Use and Occupancy.
8-102.1.4 Continued use. Qualified historical buildings or properties may have their existing use or occupancy continued if such use or occupancy conformed to the code or to the standards of construction in effect at the time of construction, and such use or occupancy does not constitute a distinct hazard to life safety as defined in the CHBC.
8-102.1.5 Unsafe buildings or properties. When a qualified historical building or property is determined to be unsafe as defined in the regular code, the requirements of the CHBC are applicable to the work necessary to correct the unsafe conditions. Work to remediate the buildings or properties need only address the correction of the unsafe conditions, and it shall not be required to bring the entire qualified historical building or property into compliance with regular code.
CHBC § 8-3 High relevance — show source text
TREATMENT. An act of work to carry out preservation, restoration, stabilization, rehabilitation or reconstruction.
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8-3 USE AND OCCUPANCY
SECTION 8-301 — PURPOSE AND SCOPE
8-301.1 Purpose. The purpose of the CHBC is to provide regulations for the determination of occupancy classifications and conditions of use for qualified historical buildings or properties.
8-301.2 Scope. Every qualified historical building or property for which a permit or approval has been requested shall be classified prior to permit issuance according to its use or the character of its occupancy in accordance with the regular code and applicable provisions of this chapter.
SECTION 8-302 — GENERAL
8-302.1 Existing use. The use or character of occupancy of a qualified historical building or property, or portion thereof, shall be permitted to continue in use regardless of any period of time in which it may have remained unoccupied or in other uses, provided such building or property otherwise conforms to all applicable requirements of the CHBC.
8-302.2 Change in occupancy. The use or character of the occupancy of a qualified historical building or property may be changed from or returned to its historical use or character, provided the qualified historical building or property conforms to the requirements applicable to the new use or character of occupancy as set forth in the CHBC. Such change in occupancy shall not mandate conformance with new construction requirements as set forth in regular code.
8-302.3 Occupancy separations. Required occupancy separations of more than one hour may be reduced to one-hour fire-resistive construction with all openings protected by not less than three-fourths-hour fire-resistive assemblies of the self-closing or automatic-closing type when the building is provided with an automatic sprinkler system throughout the entire building in accordance with Section 8-410.2. Doors equipped with automatic-closing devices shall be of a type which will function upon activation of a device which responds to products of combustion other than heat.
Required occupancy separations of one hour may be omitted when the building is provided with an automatic sprinkler system throughout.
8-302.4 Maximum floor area. Regardless of the use or character of occupancy, the area of a one-story qualified historical building or property may have, but shall not exceed, a floor area of 15,000 square feet (1393.5 m [2] ) unless such an increase is otherwise permitted in regular code. Multistory qualified historical buildings (including basements and cellars) shall be in accordance with regular code requirements.
Exception: Historical buildings may be unlimited in floor area without fire-resistive area separation walls:
- When provided with an automatic sprinkler, or
- Residential occupancies of two stories or less when provided with a complete fire alarm and annunciation system and where the exiting system conforms to regular code.
8-302.5 Maximum height. The maximum height and number of stories of a qualified historical building or property shall not be limited because of construction type, provided such height or number of stories does not exceed that of its historical design.
CHBC § 8-302.3 Medium relevance — show source text
8-302.3 Occupancy separations. Required occupancy separations of more than one hour may be reduced to one-hour fire-resistive construction with all openings protected by not less than three-fourths-hour fire-resistive assemblies of the self-closing or automatic-closing type when the building is provided with an automatic sprinkler system throughout the entire building in accordance with Section 8-410.2. Doors equipped with automatic-closing devices shall be of a type which will function upon activation of a device which responds to products of combustion other than heat.
Required occupancy separations of one hour may be omitted when the building is provided with an automatic sprinkler system throughout.
8-302.4 Maximum floor area. Regardless of the use or character of occupancy, the area of a one-story qualified historical building or property may have, but shall not exceed, a floor area of 15,000 square feet (1393.5 m [2] ) unless such an increase is otherwise permitted in regular code. Multistory qualified historical buildings (including basements and cellars) shall be in accordance with regular code requirements.
Exception: Historical buildings may be unlimited in floor area without fire-resistive area separation walls:
- When provided with an automatic sprinkler, or
- Residential occupancies of two stories or less when provided with a complete fire alarm and annunciation system and where the exiting system conforms to regular code.
8-302.5 Maximum height. The maximum height and number of stories of a qualified historical building or property shall not be limited because of construction type, provided such height or number of stories does not exceed that of its historical design.
8-302.5.1 High-rise buildings. Occupancies B, F-1, F-2 or S in high-rise buildings with floors located more than 75 feet above the lowest floor level having building access may be permitted with only the stories over 75 feet provided with an automatic fire sprinkler system if:
- The building construction type and the exits conform to regular code, and
- A complete building fire alarm and annunciation system is installed, and
- A fire barrier is provided between the sprinklered and nonsprinklered floors.
8-302.6 Fire-resistive construction. See Chapter 8-4.
8-302.7 Light and ventilation. Existing provisions for light and ventilation which do not, in the opinion of the enforcing agency, constitute a safety hazard may remain. See Section 8-303.6 for residential requirements. See Section 8-503 for Escape or Rescue Windows and Doors.
SECTION 8-303 — RESIDENTIAL OCCUPANCIES
8-303.1 Purpose. The purpose of this section is to provide regulations for those buildings designated as qualified historical buildings or properties and classified as residential occupancies. The CHBC requires enforcing agencies to accept any reasonably equivalent alternative to the regular code when dealing with qualified historical buildings and properties.
8-303.2 Intent. The intent of the CHBC is to preserve the integrity of qualified historical buildings and properties while maintaining a reasonable degree of protection of life, health and safety for the occupants.
8-303.3 Application and scope. The provisions of this section shall apply to all qualified historical buildings used for human habitation. Those dwelling units intended only for display, or public use with no residential use involved, need not comply with the requirements of this section.
8-303.4 Fire escapes. See Chapter 8-5.
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CHBC § 8-7 Medium relevance — show source text
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8-7 STRUCTURAL REGULATIONS
SECTION 8-701 — PURPOSE, INTENT AND SCOPE
8-701.1 Purpose. The purpose of the CHBC is to provide alternative regulations to the regular code for the structural safety of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.
8-701.2 Intent. The intent of this chapter is to encourage the preservation of qualified historical buildings or structures while providing standards for a minimum level of building performance with the objective of preventing partial or total structural collapse such that the overall risk of life-threatening injury as a result of structural collapse is low.
8-701.3 Application. The alternative structural regulations provided by Section 8-705 are to be applied in conjunction with the regular code whenever a structural upgrade or reconstruction is undertaken for qualified historical buildings or properties.
SECTION 8-702 — GENERAL
8-702.1 The CHBC shall not be construed to allow the enforcing agency to approve or permit a lower level of safety of structural design and construction than that which is reasonably equivalent to the regular code provisions in occupancies which are critical to the safety and welfare of the public at large, including, but not limited to, public and private schools, hospitals, municipal police and fire stations and essential services facilities.
8-702.2 Nothing in these regulations shall prevent voluntary and partial seismic upgrades when it is demonstrated that such upgrades will improve life safety and when a full upgrade would not otherwise be required.
SECTION 8-703 — STRUCTURAL SURVEY
8-703.1 Scope. When a structure or portion of a structure is to be evaluated for structural capacity under the CHBC, it shall be surveyed for structural conditions by an architect or engineer knowledgeable in historical structures. The survey shall evaluate deterioration or signs of distress. The survey shall determine the details of the structural framing and the system for resistance of gravity and lateral loads. Details, reinforcement and anchorage of structural systems and veneers shall be determined and documented where these members are relied on for seismic lateral resistance.
8-703.2 The results of the survey shall be utilized for evaluating the structural capacity and for designing modifications to the structural system to reach compliance with this code.
8-703.3 Historical records. Past historical records of the structure or similar structures may be used in the evaluation, including the effects of subsequent alterations.
SECTION 8-704 — NONHISTORICAL ADDITIONS AND NONHISTORICAL ALTERATIONS
8-704.1 New nonhistorical additions and nonhistorical alterations which are structurally separated from an existing historical building or structure shall comply with regular code requirements.
8-704.2 New nonhistorical additions which impose vertical or lateral loads on an existing structure shall not be permitted unless the affected part of the supporting structure is evaluated and strengthened, if necessary, to meet regular code requirements.
Note: For use of archaic materials, see Chapter 8-8.
SECTION 8-705 — STRUCTURAL REGULATIONS
CHBC § 8-604 Medium relevance — show source text
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ACCESSIBILITY
SECTION 8-604 — EQUIVALENT FACILITATION
Use of other designs and technologies, or deviation from particular technical and scoping requirements, are permitted if the application of the alternative provisions contained in Section 8-603 would threaten or destroy the historical significance or characterdefining features of the historical building or property.
- Such alternatives shall be applied only on an item-by- item or a case-by-case basis.
- Access provided by experiences, services, functions, materials and resources through methods including, but not limited to, maps, plans, videos, virtual reality and related equipment, at accessible levels. The alternative design and/or technologies used will provide substantially equivalent or greater accessibility to, and usability of, the facility.
- The official charged with the enforcement of the standards shall document the reasons for the application of the design and/or technologies and their effect on the historical significance or character-defining features. Such documentation shall be in accordance with Section 8-602.2, Item 2, and shall include the opinion and comments of state or local accessibility officials, and the opinion and comments of representative local groups of people with disabilities. Such documentation shall be retained in the permanent file of the enforcing agency. Copies of the required documentation should be available at the facility upon request.
Note: For commercial facilities and places of public accommodation (Title III entities).
Equivalent facilitation for an element of a building or property when applied as a waiver of an ADA accessibility requirement will not be entitled to the Federal Department of Justice certification of this code as rebuttable evidence of compliance for that element.
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8-7 STRUCTURAL REGULATIONS
SECTION 8-701 — PURPOSE, INTENT AND SCOPE
8-701.1 Purpose. The purpose of the CHBC is to provide alternative regulations to the regular code for the structural safety of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.
8-701.2 Intent. The intent of this chapter is to encourage the preservation of qualified historical buildings or structures while providing standards for a minimum level of building performance with the objective of preventing partial or total structural collapse such that the overall risk of life-threatening injury as a result of structural collapse is low.
8-701.3 Application. The alternative structural regulations provided by Section 8-705 are to be applied in conjunction with the regular code whenever a structural upgrade or reconstruction is undertaken for qualified historical buildings or properties.
SECTION 8-702 — GENERAL
8-702.1 The CHBC shall not be construed to allow the enforcing agency to approve or permit a lower level of safety of structural design and construction than that which is reasonably equivalent to the regular code provisions in occupancies which are critical to the safety and welfare of the public at large, including, but not limited to, public and private schools, hospitals, municipal police and fire stations and essential services facilities.
8-702.2 Nothing in these regulations shall prevent voluntary and partial seismic upgrades when it is demonstrated that such upgrades will improve life safety and when a full upgrade would not otherwise be required.
CHBC § 8-102.1.6 Medium relevance — show source text
8-102.1.6 Additional work. Qualified historical buildings or properties shall not be subject to additional work required by the regular code, regulation or ordinance beyond that required to complete the work undertaken. Certain exceptions for accessibility and for distinct hazards exist by mandate and may require specific action, within the parameters of the CHBC.
SECTION 8-103 — ORGANIZATION AND ENFORCEMENT
8-103.1 Authority. The state or local enforcing agency, pursuant to authority provided under Section 18954 of the Health and Safety Code, shall administer and enforce the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, reconstruction, rehabilitation, relocation or continued use of a qualified historical building or property.
8-103.2 State enforcement. All state agencies pursuant to authority provided under Section 18954 and Section 18961 of the Health and Safety Code shall administer and enforce the CHBC with respect to qualified historical buildings or properties under their respective jurisdiction.
8-103.3 Liability. Prevailing law regarding immunity of building officials is unaffected by the use and enforcement of the CHBC.
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ADMINISTRATION
SECTION 8-104 — REVIEW AND APPEALS
8-104.1 State Historical Building Safety Board (SHBSB or Board). In order to provide for interpretation of the provisions of the CHBC and to hear appeals, the SHBSB shall act as an appeal and review body to state and local agencies or any affected party.
8-104.2 SHBSB review. When a proposed design, material or method of construction is being considered by the enforcing agency, the agency chief, the building official or the local board of appeals may file a written request for opinion to the SHBSB for its consideration, advice or findings. In considering such request, the SHBSB may seek the advice of other appropriate private or public boards, individuals, or state or local agencies. The SHBSB shall, after considering all of the facts presented, including any recommendation of other appropriate boards, agencies or other parties, determine if, for the purpose intended, the proposal is reasonably equivalent to that allowed by these regulations in proposed design, material or method of construction, and it shall transmit such findings and its decision to the enforcing agency for its application. The Board may recover the costs of such reviews and shall report the decision in printed form, copied to the California Building Standards Commission.
8-104.2.1 State agencies. All state agencies with ownership of, or that act on behalf of state agency owners of, qualified historical buildings or properties, shall consult and obtain SHBSB review prior to taking action or making decisions or appeals that affect qualified historical buildings or properties, per Section 18961 of the Health and Safety Code.
8-104.2.2 Imminent threat. Where an emergency is declared and a qualified historical building or property is declared an imminent threat to life and safety, the state agency assessing such a threat shall consult with the SHBSB before any demolition is undertaken, per Section 18961 of the Health and Safety Code.
CHBC § 1001.1 Medium relevance — show source text
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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
CHBC § 8-702.2 Medium relevance — show source text
8-702.2 Nothing in these regulations shall prevent voluntary and partial seismic upgrades when it is demonstrated that such upgrades will improve life safety and when a full upgrade would not otherwise be required.
SECTION 8-703 — STRUCTURAL SURVEY
8-703.1 Scope. When a structure or portion of a structure is to be evaluated for structural capacity under the CHBC, it shall be surveyed for structural conditions by an architect or engineer knowledgeable in historical structures. The survey shall evaluate deterioration or signs of distress. The survey shall determine the details of the structural framing and the system for resistance of gravity and lateral loads. Details, reinforcement and anchorage of structural systems and veneers shall be determined and documented where these members are relied on for seismic lateral resistance.
8-703.2 The results of the survey shall be utilized for evaluating the structural capacity and for designing modifications to the structural system to reach compliance with this code.
8-703.3 Historical records. Past historical records of the structure or similar structures may be used in the evaluation, including the effects of subsequent alterations.
SECTION 8-704 — NONHISTORICAL ADDITIONS AND NONHISTORICAL ALTERATIONS
8-704.1 New nonhistorical additions and nonhistorical alterations which are structurally separated from an existing historical building or structure shall comply with regular code requirements.
8-704.2 New nonhistorical additions which impose vertical or lateral loads on an existing structure shall not be permitted unless the affected part of the supporting structure is evaluated and strengthened, if necessary, to meet regular code requirements.
Note: For use of archaic materials, see Chapter 8-8.
SECTION 8-705 — STRUCTURAL REGULATIONS
8-705.1 Gravity loads. The capacity of the structure to resist gravity loads shall be evaluated and the structure strengthened as necessary. The evaluation shall include all parts of the load path. Where no distress is evident, and a complete load path is present, the structure may be assumed adequate by having withstood the test of time if anticipated dead and live loads will not exceed those historically present.
8-705.2 Wind and seismic loads. The ability of the structure to resist wind and seismic loads shall be evaluated. Wind loads shall be considered when appropriate, but need not exceed 75 percent of the wind loads prescribed by the regular code. The evaluation shall be based on the requirements of Section 8-706.
8.705.2.1 Any unsafe conditions in the lateral-load-resisting system shall be corrected, or alternative resistance shall be provided. When strengthening is required, additional resistance shall be provided to meet the minimum requirements of the CHBC. The strengthening measures shall be selected with the intent of meeting the performance objectives set forth in Section 8-701.2. The evaluation of structural members and structural systems for seismic loads shall consider the inelastic performance of structural members and their ability to maintain load-carrying capacity during the seismic loadings prescribed by the regular code.
8.705.2.2 The architect or engineer shall consider additional measures with minimal loss of, and impact to, historical materials which will reduce damage and needed repairs in future earthquakes to better preserve the historical structure in perpetuity. These additional measures shall be presented to the owner for consideration as part of the rehabilitation or restoration.
2025 CALIFORNIA HISTORICAL BUILDING CODE 13
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
STRUCTURAL REGULATIONS
CHBC § 8-801 Medium relevance — show source text
SECTION 8-801 — PURPOSE, INTENT AND SCOPE
8-801.1 Purpose. The purpose of the CHBC is to provide regulations for the use of historical methods and materials of construction that are at variance with regular code requirements or are not otherwise codified, in buildings or structures designated as qualified historical buildings or properties. The CHBC require enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.
8-801.2 Intent. It is the intent of the CHBC to provide for the use of historical methods and materials of construction that are at variance with specific code requirements or are not otherwise codified.
8-801.3 Scope. Any construction type or material that is, or was, part of the historical fabric of a structure is covered by this chapter. Archaic materials and methods of construction present in a historical structure may remain or be reinstalled or be installed with new materials of the same class to match existing conditions.
SECTION 8-802 — GENERAL ENGINEERING APPROACHES
Strength values for archaic materials shall be assigned based upon similar conventional codified materials, or on tests as hereinafter indicated. The archaic materials and methods of construction shall be thoroughly investigated for their details of construction in accordance with Section 8-703. Testing shall be performed when applicable to evaluate existing conditions. The architect or structural engineer in responsible charge of the project shall assign allowable stresses or strength levels to archaic materials. Such assigned strength values shall not be greater than those provided for in the following sections without adequate testing, and shall be subject to the concurrence of the enforcing agency.
SECTION 8-803 — NONSTRUCTURAL ARCHAIC MATERIALS
Where nonstructural historical materials exist in uses which do not meet the requirements of the regular code, their continued use is allowed by this code, provided that any public health and life safety hazards are mitigated subject to the concurrence of the enforcing agency.
SECTION 8-804 — ALLOWABLE CONDITIONS FOR SPECIFIC MATERIALS
Archaic materials which exist and are to remain in qualified historical buildings or structures shall be evaluated for their condition and for loads required by this code. The structural survey required in Section 8-703 of the CHBC shall document existing conditions, reinforcement, anchorage, deterioration and other factors pertinent to establishing allowable stresses, strength levels and adequacy of the archaic materials. The remaining portion of this chapter provides additional specific requirements for commonly encountered archaic materials.
SECTION 8-805 — MASONRY
For adobe, see Section 8-806.
8-805.1 Existing solid masonry. Existing solid masonry walls of any type, except adobe, may be allowed, without testing, a maximum ultimate strength of 9 pounds per square inch (62.1 kPa) in shear where there is a qualifying statement by the architect or engineer that an inspection has been made, that mortar joints are filled and that both brick and mortar are reasonably good. The shear stress above applies to unreinforced masonry, except adobe, where the maximum ratio of unsupported height or length to thickness does not exceed 13, and where minimum quality mortar is used or exists. Wall height or length is measured to supporting or resisting elements that are at least twice as stiff as the tributary wall. Stiffness is based on the gross section. Shear stress may be increased by the addition of 10 percent of the axial direct stress due to the weight of the wall directly above.
California Historical Building Code Medium relevance — show source text
Exceptions:
- Certificates of occupancy are not required for work exempt from permits under Section R105.2.
- Accessory buildings or structures.
R110.2 Certificate issued. After the building official inspects the building or structure and does not find violations of the provisions of this code or other laws that are enforced by the department, the building official shall issue a certificate of occupancy containing 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.
The name of the building official.
The edition of the code under which the permit was issued.
Where an automatic sprinkler system is provided and whether the sprinkler system is required.
Any special stipulations and conditions of the building permit.
R110.3 Temporary occupancy. The building official is authorized to issue a temporary certificate of occupancy before the completion of the entire work covered by the permit, provided that such portion or portions shall be occupied safely. The building official shall set a time period during which the temporary certificate of occupancy is valid.
R110.4 Revocation. The building official is authorized to suspend or revoke a certificate of occupancy issued under the provisions of this code, in writing, wherever the certificate is issued in error, or on the basis of incorrect information supplied, or where it is determined that the building or structure or portion thereof is in violation of the provisions of this code or other ordinance of the jurisdiction.
SECTION R111—SERVICE UTILITIES
R111.1 Connection of service utilities. A person shall not make connections from a utility, a source of energy, fuel or power, or water system or sewer system to any building or system that is regulated by this code for which a permit is required, until approved by the building official.
R111.2 Temporary connection. The building official shall have the authority to authorize the temporary connection of the building or system to the utility, source of energy, fuel or power, water system or sewer system for the purpose of testing systems for use under a temporary approval.
R111.3 Authority to disconnect service utilities. The building official shall have the authority to authorize disconnection of utility service to the building, structure or system regulated by this code and the referenced codes and standards in case of emergency where necessary to eliminate an immediate hazard to life or property or where such utility connection has been made without the approval required by Section R111.1 or R111.2. The building official shall notify the serving utility and where possible the owner or the owner’s authorized agent and occupant of the building, structure or service system of the decision to disconnect prior to taking such action. If not notified prior to disconnection, the owner, the owner’s authorized agent or occupant of the building, structure or service system shall be notified in writing as soon as practical thereafter.
SECTION R112—MEANS OF APPEALS
R112.1 General. In order to hear and decide appeals of orders, decisions or determinations made by the building official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The board of appeals shall be appointed by the applicable governing authority and shall hold office at its pleasure. The board shall adopt rules of procedure for conducting its business, and shall render all decisions and findings in writing to the appellant with a duplicate copy to the building official.
Frequently asked questions
When does a building qualify to use the CHBC instead of regular code?
A property must be a qualified historical building or property (designated or eligible by an appropriate jurisdiction) and the owner must elect to use the CHBC; see § 8-102.1.
If a building was vacant for decades, can it still continue its historic occupancy?
Yes — § 8-302.1 permits continuation of an existing use “regardless of any period of time in which it may have remained unoccupied,” provided CHBC requirements are met and no distinct hazard exists.
What happens if inspectors find the building is “unsafe”?
If the building is declared unsafe under the regular code, CHBC governs the remediation work but requires only the work necessary to correct the unsafe conditions rather than full building‑wide upgrades (see § 8-102.1.5).
Does reopening require sprinklers or full seismic retrofit?
Not automatically. The enforcing agency may accept targeted remedies (sprinklers, life‑safety evaluation, limited strengthening) in lieu of a full upgrade. CHBC lists tradeoffs such as those in § 8-402.2 and structural chapters for survey/strengthening measures.
Can a nonhistorical addition to a historic building use CHBC relief?
No — nonhistorical additions generally must meet the regular code; CHBC allows historic fabric to be preserved but nonhistorical expansion is treated under regular code § 8-102.1.1 and § 8‑704.
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