CHBC · California Historical Building Code
How do "building standard" and "enforcing agency" operate for CHBC work?
If your building is a qualified historic property and you (the owner) elect CHBC application, the local or state enforcing agency must apply the CHBC and may accept alternative building standards or solutions judged reasonably equivalent to the regular code; agencies should limit required upgrades to work necessary for the project and may seek SHBSB review when technical equivalence is in question. (§ 8-201; § 8-103)
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The CHBC defines BUILDING STANDARD as “any guideline, regulation or code that may be applied to a qualified historical building or property” (§ 8-201) and directs the state or local enforcing agency to administer and enforce the CHBC when permitting work on qualified historical buildings (§ 8-103.1) . State agencies must likewise apply the CHBC for properties under their jurisdiction (§ 8-103.2) and prevailing law about building-official immunity remains in effect (§ 8-103.3) .
The enforcing agency (local or state) applies the CHBC to qualified historic buildings and must accept reasonably equivalent building standards and solutions instead of automatically forcing full compliance with the regular code. (§ 8-103.1; § 8-201)
Requirements in detail
1) What a “building standard” is and how it’s used
- BUILDING STANDARD: any guideline, regulation or code that can be applied to a qualified historical building or property (§ 8-201) .
- Practical meaning: the CHBC allows using either the CHBC solutions or other standards so long as the enforcing agency accepts them as reasonably equivalent to the regular code (see enforcement and solutions sections) .
2) Who is the “enforcing agency” and what must it do
- The state or local enforcing agency must administer and enforce the CHBC for qualified historical buildings when permitting repairs, alterations and additions (§ 8-103.1) .
- All state agencies have the same responsibility for buildings under their control (§ 8-103.2) .
- Liability/immunity rules that apply to building officials under prevailing law are unchanged by use of the CHBC (§ 8-103.3) .
3) How enforcing agencies apply CHBC vs. the regular code
- The CHBC is applied to qualified historical buildings and may be used alongside the regular code; the enforcing agency must accept reasonable equivalent solutions to the regular code when appropriate (see CHBC purpose and solutions) (§ 8-101.2, § 8-105.2) .
- The state/local enforcing agency applies the CHBC when the private property owner elects to use it for work on a qualified historical building (§ 8-102.1, item 1) .
- The enforcing agency may request evidence to substantiate alternatives and must find them reasonably equivalent in quality, strength, effectiveness, durability and safety (§ 8-105.2) .
4) Scope limits and “additional work”
- The CHBC generally limits required upgrades to only the work necessary to complete the project; qualified historical buildings are not to be subject to additional regular-code work beyond what’s necessary for the requested work (§ 8-102.1.6) .
- If the structure is unsafe by the regular code definition, CHBC applies only to the corrective work to remedy the unsafe condition—not to bring the whole building into full regular-code compliance (§ 8-102.1.5) .
Decision table — what the enforcing agency looks at
| Decision dimension | Possible values / actions | Code reference |
|---|---|---|
| Is the structure a qualified historical building? | Yes → CHBC applies when elected; No → regular code applies | § 8-102.1 |
| Who enforces? | Local or state enforcing agency depending on jurisdiction | § 8-103.1–.2 |
| Definition of “building standard” | Any guideline/regulation/code applied to the property | § 8-201 |
| Extent of required upgrades | Only work necessary for the project; limited exceptions for accessibility/distinct hazards | § 8-102.1.6 |
| Alternatives / equivalency | Enforcing agency may accept alternatives judged reasonably equivalent; evidence may be requested | § 8-105.2 |
| Appeals / technical review | SHBSB may be consulted for interpretation and review | § 8-104.2 |
Exceptions & special cases
- State agencies enforce the CHBC for state-owned historic properties under their jurisdiction—this is explicit and not optional (§ 8-103.2) .
- The CHBC does not automatically exempt a building from mandated accessibility or distinct hazard requirements; certain mandates may require specific action even for historic buildings (see limits in § 8-102.1.6) .
- When an imminent threat to life/safety exists, state agencies must consult the State Historical Building Safety Board (SHBSB) before demolition or certain emergency actions per Health & Safety Code procedures and § 8-104.2.2 (SHBSB review) .
- If an enforcing agency is unsure whether a proposed alternative is equivalent, it can request SHBSB review or obtain evidence to substantiate the alternative’s equivalency (§ 8-104.2; § 8-105.2) .
Common mistakes
- Assuming CHBC always removes the need to meet any regular code requirement. The CHBC provides alternative solutions and accepts equivalent methods but does not automatically waive safety obligations—enforcing agencies must still be satisfied that alternatives are reasonably equivalent (§ 8-101.2, § 8-105.2) .
- Believing an enforcing agency can apply the CHBC without owner election (for private buildings). For privately owned qualified historical buildings, the owner elects to use the CHBC and the enforcing agency then applies it (§ 8-102.1, item 1) .
- Requiring full regular-code upgrades for unrelated parts of the building when only a limited scope of work is proposed. The CHBC prohibits imposing additional regular-code work beyond what’s required to complete the work undertaken, except certain mandated items (accessibility/distinct hazards) (§ 8-102.1.6) .
- Forgetting state agencies’ obligation: state agencies must apply the CHBC to qualified historical properties under their control (§ 8-103.2) .
Worked example — step-by-step scenario
Scenario: A homeowner wants to replace original wood windows on a 1915 commercial storefront listed on the city’s historic register. The owner prefers in-kind repair and custom sash restoration rather than new code-compliant egress windows.
- Owner elects to have the permit application reviewed under the CHBC (owner election triggers CHBC application for private properties) — § 8-102.1 .
- The local enforcing agency (building department) reviews the proposed in-kind solution and evaluates whether the proposed repair/replication is reasonably equivalent for life safety and egress purposes. The agency may accept the CHBC solution or require limited modifications only to address distinct hazards or accessibility mandates (§ 8-103.1; § 8-105.2) .
- If the agency needs expert guidance or believes an alternate method may be equivalent, it may request supporting evidence (test reports, engineering statements) and/or seek SHBSB opinion under the appeal/review provisions (§ 8-105.2; § 8-104.2) .
- If the agency accepts the in-kind solution as reasonably equivalent, the permit is issued limited to the work proposed. The agency should not require wholesale replacement of other building elements unrelated to the window work, because additional work beyond that required to complete the work undertaken is prohibited unless mandated (accessibility/distinct hazard) (§ 8-102.1.6) .
Numeric example of limits (illustrative, not a new code number): if the proposed work affects only 2 storefront windows (project scope = 2 openings), the enforcing agency should require upgrades only as related to those 2 openings (for example, restoring operability or providing a removable emergency egress device if that corrects the life-safety concern), not replace all 10 windows on the block face—because CHBC limits additional work to that necessary to complete the work undertaken (§ 8-102.1.6) .
Related provisions
- § 8-101.2 — Purpose; CHBC requires enforcing agencies to accept reasonably equivalent solutions to the regular code .
- § 8-102.1 — Application (owner election; when CHBC is used) .
- § 8-102.1.5 — Unsafe buildings — CHBC applies to work required to correct unsafe conditions only .
- § 8-102.1.6 — Additional work limitation: no extra regular-code work beyond that required to complete the work undertaken (exceptions for accessibility/distinct hazards) .
- § 8-104.2 — SHBSB review procedures for enforcing agencies and appeals (consultation and interpretation) .
- § 8-105.2 — Acceptance of alternatives; enforcing agency may require proof of equivalency .
- § 8-103.3 — Liability: prevailing law regarding immunity of building officials unaffected by CHBC use .
Code references
Grounded in the retrieved California Historical Building Code — click a citation to read the verbatim passage:
CHBC § 323-9843 High relevance — show source text
State Librarian [SL]
library.ca.gov csllaw@library.ca.gov (916) 323-9843 Public Library Construction & Renovation
2025 CALIFORNIA HISTORICAL BUILDING CODE v
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HOW TO DETERMINE WHERE CHANGES HAVE BEEN MADE
Symbols in the margins indicate where changes have been made or language has been deleted.
This symbol indicates that a change has been made.
- This symbol indicates deletion of language.
vi 2025 CALIFORNIA HISTORICAL BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PART 8 CONTAINS ALTERNATIVE REGULATIONS
FOR QUALIFIED HISTORICAL BUILDINGS
The California Historical Building Code (CHBC) is unique among state regulations. The authoring of the original CHBC required state agencies promulgating regulations for building construction to work in harmony with representatives of other design and construction disciplines. The result was a totally new approach to building codes for historical structures, which maintains currently acceptable life safety standards. These regulations are also unique in that they are performance oriented rather than prescriptive. The provisions of the CHBC are to be applied by the enforcing authority of every city, county, city and county, or state agency in permitting repairs, alterations and additions necessary for the preservation, rehabilitation, relocation, related construction, change of use or continued use of a qualified historical building. The authority for use of the CHBC is vested in Sections 18950 through 18961 of the Health and Safety Code. Section 18954 states, “The building department of every city or county or other local agency that has jurisdiction over the enforcement of code within its legal authority shall apply the alternative standards and regulations adopted pursuant to Section 18959.5 in permitting repairs, alterations, and additions necessary for the preservation, restoration, rehabilitation, safety, moving, or continued use of a qualified historical building or structure. A state agency shall apply the alternative regulations adopted pursuant to Section 18959.5 in permitting repairs, alterations, and additions necessary for the preservation, restoration, rehabilitation, safety, moving, or continued use of a qualified historical building or structure.” However, be aware that in order to use the CHBC, the structure under consideration must be qualified by being designated as an historical building or structure. Section 18955 states, “For the purposes of this part, a qualified historical building or structure is any structure or property, collection of structures, and their related sites deemed of importance to the history, architecture, or culture of an area by an appropriate local or state governmental jurisdiction. This shall include historical buildings or structures on existing or future national, state or local historical registers or official inventories, such as the National Register of Historic Places, State Historical Landmarks, State Points of Historical Interest, and city or county registers or inventories of historical or architecturally significant sites, places, historic districts, or landmarks. This shall also include places, locations, or sites identified on these historical registers or official inventories and deemed of importance to the history, architecture, or culture of an area by an appropriate local or state governmental jurisdiction.” The regulations of the CHBC have the same authority as state law and are to be considered as such. Liability is the same as for prevailing law. The intent of the CHBC is to save California’s architectural heritage by recognizing the unique construction problems inherent in historical buildings and by providing a code to deal with these problems.
CHBC § 8-102.1.6 High 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.
2025 CALIFORNIA HISTORICAL BUILDING CODE 1
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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 § 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 § 653-5791 High relevance — show source text
Option 5 > Option 2 State Housing Law: including Housing Accessibility, Hotels/Motels, Apartments/Condominiums, Dormitories, Single-Family Dwellings, ADUs, Permanent Structures in Mobile Home Parks
Option 5 > Option 4 Factory-Built Housing Option 5 > Option 5 Employee Housing
Department of Water Resources [DWR]
water.ca.gov DWRwebcomment@water.ca.gov
(916) 653-5791 Plumbing for Recycled Water, Floodplain Construction
Division of the State Architect
dgs.ca.gov/DSA (916) 445-8100
Access Compliance DSAAC 445-5827 DSAaccess@dgs.ca.gov Access for Persons with Disabilities
Structural Safety [DSA-SS, DSA-SS/CC]
Public Schools & Community Colleges, State Essential Services Buildings
State Historical Building Safety Board [SHBSB] (916) 445-7627 shbsb@dgs.ca.gov
Historical Building Rehabilitation, Preservation, Restoration or Relocation
Energy Commission [CEC]
energy.ca.gov Title24@energy.ca.gov (800) 772-3300 Building Energy Efficiency, Compliance Manual & Compliance Forms
Office of the State Fire Marshal [SFM]
osfm.fire.ca.gov codedevelopment@fire.ca.gov
(916) 568-3800 Fire & Life Safety
State Lands Commission [SLC]
slc.ca.gov MOTEMS.Public@slc.ca.gov (510) 741-4950 Marine Oil Terminals
State Librarian [SL]
library.ca.gov csllaw@library.ca.gov (916) 323-9843 Public Library Construction & Renovation
2025 CALIFORNIA HISTORICAL BUILDING CODE v
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HOW TO DETERMINE WHERE CHANGES HAVE BEEN MADE
Symbols in the margins indicate where changes have been made or language has been deleted.
This symbol indicates that a change has been made.
- This symbol indicates deletion of language.
vi 2025 CALIFORNIA HISTORICAL BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PART 8 CONTAINS ALTERNATIVE REGULATIONS
FOR QUALIFIED HISTORICAL BUILDINGS
The California Historical Building Code (CHBC) is unique among state regulations. The authoring of the original CHBC required state agencies promulgating regulations for building construction to work in harmony with representatives of other design and construction disciplines. The result was a totally new approach to building codes for historical structures, which maintains currently acceptable life safety standards. These regulations are also unique in that they are performance oriented rather than prescriptive. The provisions of the CHBC are to be applied by the enforcing authority of every city, county, city and county, or state agency in permitting repairs, alterations and additions necessary for the preservation, rehabilitation, relocation, related construction, change of use or continued use of a qualified historical building. The authority for use of the CHBC is vested in Sections 18950 through 18961 of the Health and Safety Code.
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 § 8-104.2 High relevance — show source text
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.
8-104.3 SHBC appeals. If any local agency administering and enforcing the CHBC or any person adversely affected by any regulation, rule, omission, interpretation, decision or practice of the agency enforcing the CHBC wishes to appeal the issue for resolution to the SHBSB, either of these parties may appeal directly to the Board. The Board may accept the appeal only if it determines that issues involved are of statewide significance. The Board may recover the costs of such reviews and shall make available copies of decisions in printed form at cost, copied to the California Building Standards Commission.
8-104.4 Local agency fees. Local agencies, when actively involved in the appeal, may also charge affected persons reasonable fees not to exceed the cost of obtaining reviews and appeals from the Board.
SECTION 8-105 — CONSTRUCTION METHODS AND MATERIALS
8-105.1 Repairs. Repairs to any portion of a qualified historical building or property may be made in-kind with historical materials and the use of original or existing historical methods of construction, subject to conditions of the CHBC. (See Chapter 8-8.)
8-105.2 Solutions to the California Historical Building Code . Solutions provided in the CHBC, or any other acceptable regulation or methodology of design or construction and used in whole or in part, with the regular code, or with any combination of the regular code and the CHBC, shall be allowed. The CHBC does not preclude the use of any proposed alternative or method of design or construction not specifically prescribed or otherwise allowed by these regulations. Any alternative may be submitted for evaluation to the appropriate enforcing agency for review and acceptance. The enforcing agency may request that sufficient evidence or proof be submitted to substantiate any claims that may be made regarding such solutions. Any alternative offered in lieu of that prescribed or allowed in the CHBC shall be reasonably equivalent in quality, strength, effectiveness, durability and safety to that of the CHBC.
CHBC § 12.7 High relevance — show source text
Values are for strength level loads as defined in regular code standards.
2. Values may be adjusted for other fasteners when approved by the enforcing authority.
3. In addition to existing sheathing value.
4. Bolts to be1/2-inch (12.7 mm) minimum diameter.
5. Other bolt sizes, values and installation methods may be used provided a testing program is conducted in accordance with regular code standards. Bolt spacing shall not
exceed 6 feet (1830 mm) on center and shall not be less than 12 inches (305 mm) on center.
6. Other masonry based on tests or other substantiated data.
7. Embedded bolts to be tested as specified in regular code standards.
8. Stresses given may be increased for combinations of loads as specified in the regular code.
9. Adhesives shall be approved by the enforcing agency and installed in accordance with the manufacturer’s recommendations. All drilling dust shall be removed from drilled
holes prior to installation.|1. Values are for strength level loads as defined in regular code standards.
2. Values may be adjusted for other fasteners when approved by the enforcing authority.
3. In addition to existing sheathing value.
4. Bolts to be1/2-inch (12.7 mm) minimum diameter.
5. Other bolt sizes, values and installation methods may be used provided a testing program is conducted in accordance with regular code standards. Bolt spacing shall not
exceed 6 feet (1830 mm) on center and shall not be less than 12 inches (305 mm) on center.
6. Other masonry based on tests or other substantiated data.
7. Embedded bolts to be tested as specified in regular code standards.
8. Stresses given may be increased for combinations of loads as specified in the regular code.
9. Adhesives shall be approved by the enforcing agency and installed in accordance with the manufacturer’s recommendations. All drilling dust shall be removed from drilled
holes prior to installation.|18 2025 CALIFORNIA HISTORICAL BUILDING CODE
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8-9 MECHANICAL, PLUMBING AND ELECTRICAL REQUIREMENTS
SECTION 8-901 — PURPOSE, INTENT AND SCOPE
8-901.1 Purpose. The purpose of the CHBC is to provide regulations for the mechanical, plumbing and electrical systems of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonable equivalent solutions to the regular code when dealing with qualified historical buildings or properties.
8-901.2 Intent. The intent of the CHBC is to preserve the integrity of qualified historical buildings or properties while providing a reasonable level of protection from fire, health and life safety hazards (hereinafter referred to as safety hazards) for the building occupants.
8-901.3 Scope. The CHBC shall be applied in conjunction with the regular code whenever compliance with the regular code is required for qualified historical buildings or properties.
CHBC § 5.105.2 High relevance — show source text
Exception: Combined addition(s) to existing building(s) of two times the area or more of the existing building(s) is not eligible to meet compliance with Section 5.105.2 or Section A5.105.2.
A5.409.2 Whole building life cycle assessment. Projects shall meet the minimum requirements of Section A5.409.2 for Tier 1 or Tier 2 compliance.
A5.409.2.1 Tier 1. Projects shall conduct a cradle-to-grave whole building life cycle assessment meeting the requirements of Section 5.409.2 and performed in accordance with ISO 14040 and 14044, excluding operating energy, demonstrating a minimum 15-percent reduction in global warming potential (GWP) as compared to a reference baseline building of similar size, function, complexity, type of construction, material specification, and location that meets the requirements of all parts of the California Building Standards Code currently in effect. Software used to conduct the whole building life cycle assessment, including reference baseline building, shall have a data set compliant with ISO 14044, and ISO 21930 or EN 15804, and the software shall conform to ISO 21931 and/or EN 15978. The software tools and data sets shall be the same for evaluation of both the baseline building and the proposed building.
Exception: For projects that include building reuse, the reference baseline building shall exclude the reused elements. The percent reduction in GWP shall be achieved through the design and construction of new project elements.
A5.409.2.2 Tier 2. Projects shall conduct a cradle-to-grave whole building life cycle assessment meeting the requirements of Section 5.409.2 and performed in accordance with ISO 14040 and ISO 14044, excluding operating energy, demonstrating a minimum 20-percent reduction in GWP as compared to a reference baseline building of similar size, function, complexity, type of construction, material specification, and location that meets the requirements of all parts of the California Building Standards Code currently in effect. Software used to conduct the whole building life cycle assessment, including reference baseline building, shall have a data set compliant with ISO 14044, and ISO 21930 or EN 15804, and the software shall conform to ISO 21931 and/or EN 15978. The software tools and data sets shall be the same for evaluation of both the baseline building and the proposed building.
Exception: For projects that include building reuse, the reference baseline building shall not be of new construction and shall retain existing materials. The percent reduction in GWP shall be achieved through the design and construction of new project elements.
A5.409.2.3 Verification of compliance. A summary of the GWP analysis produced by the software and Worksheet WS-7 signed by the design professional of record shall be provided in the construction documents as documentation of compliance. A copy of the whole building life cycle assessment which includes the GWP analysis produced by the software, in addition to maintenance and training information, shall be included in the operation and maintenance manual and shall be provided to the owner at the close of construction. The enforcing agency may require inspection and inspection reports in accordance with Sections 702.2 and 703.1 during and at completion of construction to demonstrate substantial conformance. Inspection shall be performed by the design professional of record or third party acceptable to the enforcing agency.
A5.409.3 Product GWP compliance—prescriptive path. Each product that is permanently installed and listed in Table A5.409.3 shall have a Type III environmental product declaration (EPD), either product-specific or factory-specific.
CHBC § 8-9 High relevance — show source text
Bolt spacing shall not
exceed 6 feet (1830 mm) on center and shall not be less than 12 inches (305 mm) on center.
6. Other masonry based on tests or other substantiated data.
7. Embedded bolts to be tested as specified in regular code standards.
8. Stresses given may be increased for combinations of loads as specified in the regular code.
9. Adhesives shall be approved by the enforcing agency and installed in accordance with the manufacturer’s recommendations. All drilling dust shall be removed from drilled
holes prior to installation.|18 2025 CALIFORNIA HISTORICAL BUILDING CODE
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8-9 MECHANICAL, PLUMBING AND ELECTRICAL REQUIREMENTS
SECTION 8-901 — PURPOSE, INTENT AND SCOPE
8-901.1 Purpose. The purpose of the CHBC is to provide regulations for the mechanical, plumbing and electrical systems of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonable equivalent solutions to the regular code when dealing with qualified historical buildings or properties.
8-901.2 Intent. The intent of the CHBC is to preserve the integrity of qualified historical buildings or properties while providing a reasonable level of protection from fire, health and life safety hazards (hereinafter referred to as safety hazards) for the building occupants.
8-901.3 Scope. The CHBC shall be applied in conjunction with the regular code whenever compliance with the regular code is required for qualified historical buildings or properties.
8-901.4 Safety hazard. No person shall permit any safety hazard to exist on premises under their control, or fail to take immediate action to abate such hazard. Existing systems which constitute a safety hazard when operational may remain in place, provided they are completely and permanently rendered inoperative. Safety hazards created by inoperative systems shall not be permitted to exist. Requirements of the regular code concerning general regulations shall be complied with, except that the enforcing agency shall accept solutions which do not cause a safety hazard.
8-901.5 Energy conservation. Qualified historical buildings or properties covered by this part are exempted from compliance with energy conservation standards. When new nonhistorical lighting and space conditioning system components, devices, appliances and equipment are installed, they shall comply with the requirements of Title 24, Part 6, The California Energy Code, except where the historical significance or character-defining features are threatened.
SECTION 8-902 — MECHANICAL
8-902.1 General. Mechanical systems shall comply with the regular code unless otherwise modified by this chapter.
8-902.1.1 The provisions of the CHBC shall apply to the acceptance, location, installation, alteration, repair, relocation, replacement or addition of any heating, ventilating, air conditioning, domestic incinerators, kilns or miscellaneous heat-producing appliances or equipment within or attached to a historical building.
8-902.1.2 Existing systems which do not, in the opinion of the enforcing agency, constitute a safety hazard may remain in use.
8-902.1.3 The enforcing agency may approve any alternative to the CHBC which would achieve equivalent life safety.
8-902.2 Heating facilities. All dwelling-type occupancies covered under this chapter shall be provided with heating facilities. Woodburning or pellet stoves or fireplaces may be acceptable as heating facilities.
CHBC § 8-706.3 High relevance — show source text
8-706.3 Load path. A complete and continuous load path, including connections, from every part or portion of the structure to the ground shall be provided for the required forces. It shall be verified that the structure is adequately tied together to perform as a unit when subjected to earthquake forces.
8-706.4 Parapets. Parapets and exterior decoration shall be investigated for conformance with regular code requirements for anchorage and ability to resist prescribed seismic forces.
An exception to regular code requirements shall be permitted for those parapets and decorations which are judged not to be a hazard to life safety.
8-706.5 Nonstructural features. Nonstructural features of historical structure, such as exterior veneer, cornices and decorations, which might fall and create a life safety hazard in an earthquake, shall be evaluated. Their ability to resist seismic forces shall be verified, or the feature shall be strengthened with improved anchorage when appropriate.
8-706.5.1 Partitions and ceilings of corridors and stairways serving an occupant load of 30 or more shall be investigated to determine their ability to remain in place when the building is subjected to earthquake forces.
8-706.5.2 Seismic forces used to evaluate and improve nonstructural components and their anchorage, where required, shall comply with ASCE 41 or need not exceed 0.75 times the seismic forces prescribed by the requirements of the regular code.
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8-8 ARCHAIC MATERIALS AND METHODS OF CONSTRUCTION
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
CHBC § 1601A.1.2 High relevance — show source text
centers.
1601A.1.2 Amendments in this chapter. DSA-SS and OSHPD adopt this chapter and all amendments.
Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopt- ing agency, as follows: 1. Division of the State Architect-Structural Safety:
[DSA-SS] – For applications listed in Section 1.9.2.1. 2. Office of Statewide Hospital Planning and Development:
[OSHPD 1] – For applications listed in Section 1.10.1.
[OSHPD 4] – For applications listed in Section 1.10.4.
1601A.2 Enforcement agency approval. In addition to the requirements of the California Administrative Code and the California Build- ing Code, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the Registered Design Professional (RDP), are also subject to approval by the enforcement agency.
SECTION 1602 A —NOTATIONS
1602 A .1 Notations. The following notations are used in this chapter:
D = Dead load.
D i = Weight of ice in accordance with Chapter 10 of ASCE 7.
E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4 of ASCE 7.
F = Load due to fluids with well-defined pressures and maximum heights.
F a = Flood load in accordance with Chapter 5 of ASCE 7.
H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.
L = Live load.
L r = Roof live load.
p g(asd) = Allowable stress design ground snow load.
p g = Ground snow load determined from Figures 1608.2(1) through 1608.2(4) and Table 1608.2.
R = Rain load.
S = Snow load.
T = Cumulative effects of self-straining load forces and effects.
V asd = Allowable stress design wind speed, mph (m/s) where applicable.
V = Basic wind speed, V, mph (m/s) determined from Figures 1609 A .3(1) through 1609 A .3(4) or ASCE 7.
V T = Tornado speed, mph (m/s) determined from Chapter 32 of ASCE 7.
W = Load due to wind pressure.
W i = Wind-on-ice in accordance with Chapter 10 of ASCE 7.
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STRUCTURAL DESIGN
SECTION 1603 A —CONSTRUCTION DOCUMENTS
1603 A .1 General. Construction documents shall show the material, size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603 A .1.1 through 1603 A .1.10 shall be indicated on the construction documents.
CHBC § 8-1001 High relevance — show source text
Section
8-1001 Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8-1002 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8-1003 Site Relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
APPENDIX A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
HISTORY NOTE APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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8-1 ADMINISTRATION
Note: The California Historical Building Code, Part 8 of Title 24, governs for all qualified historical buildings or properties in the State of California.
SECTION 8-101 — TITLE, PURPOSE AND INTENT
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.
Frequently asked questions
Who decides whether a proposed alternative is “reasonably equivalent”?
The enforcing agency (local or state) makes the determination and may request evidence or seek SHBSB review if technical guidance is needed (§ 8-105.2; § 8-104.2) .
Can a private owner force an enforcing agency to use the CHBC?
A private owner may elect to have a qualified historical building reviewed under the CHBC; when elected, the enforcing agency applies the CHBC (§ 8-102.1, item 1) .
If there is an unsafe condition, does CHBC require full upgrade to current regular code?
No. When the building is unsafe as defined in the regular code, CHBC applies to the work necessary to correct the unsafe condition only, not to bringing the entire building into full compliance (§ 8-102.1.5) .
Do state agencies have different obligations than local agencies?
State agencies must also administer and enforce the CHBC for qualified historical properties under their jurisdiction—this is mandatory for state agencies (§ 8-103.2) .
What if the enforcing agency refuses an owner’s CHBC solution?
The owner or agency can request SHBSB review or follow the appeal procedures in § 8-104; local agencies may charge fees to cover appeal review costs (§ 8-104.2; § 8-104.4) .
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