CHBC · California Historical Building Code

Can repairs be made in‑kind using historical materials and original methods?

If your building is a qualified historic property, the CHBC (see § 8-105.1) lets you repair using the same historic materials and original methods — but you must ensure the work does not create a life‑safety or public health hazard, have archaic materials evaluated or tested as required, and obtain enforcing‑agency concurrence; alternatives can be proposed and reviewed if needed.

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Last reviewed: July 6, 2026

What the code requires — in plain English

Yes. The CHBC explicitly allows repairs to a qualified historical building or property to be made in‑kind with historical materials and the use of original or existing historical methods of construction, provided the work meets the conditions and scope of the CHBC. See § 8-105.1.

The single most important rule: If a building is a qualified historic resource, you may repair it using the same historic materials and methods — unless doing so creates a life‑safety hazard or otherwise conflicts with CHBC conditions.

Requirements in detail

Core permission

The CHBC permits in‑kind repairs (using the same historic materials and original methods) to any portion of a qualified historical building or property. See § 8-105.1.

Scope and limits

The CHBC applies only to qualified historical buildings or properties and is used when the owner or enforcing agency elects to apply Part 8. See § 8-102.1.
In‑kind repairs are subject to the broader rules for archaic materials and methods in Chapter 8‑8; the CHBC intends to permit historical materials and methods that differ from the regular code. See § 8-105.1 and § 8-801.1.
Where historical (archaic) materials remain or are reinstalled, their condition and suitability must be evaluated; structural strength values for archaic materials are to be assigned by the design professional (or by testing) and are subject to the enforcing agency’s concurrence. See § 8-802.
Nonstructural historical materials may remain in use if they do not create public health or life‑safety hazards, subject to the enforcing agency’s concurrence. See § 8-803 and § 8-303.7.
The CHBC allows the use of historical materials “installed with new materials of the same class to match existing conditions.” See § 8-801.3.

Engineering, testing and documentation

Archaic materials and methods must be thoroughly investigated per the CHBC (including the structural survey referenced in Chapter 8). The architect or structural engineer in responsible charge assigns allowable stresses; assigned values must not exceed the CHBC limits without adequate testing and enforcing‑agency concurrence. See § 8-802 (referencing § 8-703).
For specific materials (for example, existing solid masonry other than adobe), the CHBC gives allowable strength guidance (e.g., maximum ultimate shear strength values and dimension ratios). See § 8-805.1.

Alternatives and appeals

If an alternate method or material is proposed (including mixing CHBC solutions and regular code), it may be submitted to the enforcing agency for review and acceptance; the CHBC allows reasonably equivalent alternatives. See § 8-105.2.
The State Historical Building Safety Board (SHBSB) may be requested to review proposed designs, materials or methods and provide opinions on reasonable equivalence. See § 8-104.2.

Decision‑relevant dimensions (quick reference table)

Decision dimension	Values to consider	Code Reference
Is the building qualified historic?	Yes → CHBC applies; No → regular code	§ 8-102.1.
Type of work	Repair (in‑kind allowed) vs Alteration (may trigger other rules)	§ 8-105.1; § 8-303.7.
Materials allowed	Historical/archaic materials; new materials of same class to match	§ 8-801.3.
Safety constraint	No life‑safety or public health hazard may be created or continued	§ 8-303.7; § 8-803.
Structural evaluation	Structural survey, testing, engineer-assigned allowable stresses	§ 8-802 (ref. § 8-703).
Material‑specific limits	Example: existing solid masonry shear = 9 psi (conditions apply)	§ 8-805.1.
Alternate methods	May be submitted for evaluation; must be reasonably equivalent	§ 8-105.2.
Appeal / statewide guidance	SHBSB review available for statewide application	§ 8-104.2.

Exceptions & special cases

Life‑safety hazard: If retaining or reinstalling historical materials would create or continue a life‑safety or public health hazard, those materials may not be left in place without mitigation — enforcing agency concurrence required. See § 8-303.7 and § 8-803.
Structural materials and archaic methods: Structural uses of archaic materials require testing, documentation, and professional assignment of allowable stresses; values cannot exceed CHBC‑allowed levels without testing and enforcing agency concurrence. See § 8-802 and the reference to § 8-703.
Material‑specific limitations: Some sections provide specific numerical limits or conditions (for example, allowable shear for certain unreinforced masonry). Always check the relevant material section (e.g., § 8-805.1 for solid masonry).
Owner / jurisdiction election: The CHBC is applied when the structure is qualified and the owner or enforcing agency elects to use Part 8; confirm qualification per § 8-102.1.

Common mistakes

Treating "in‑kind repair" as unconditional: The CHBC allows in‑kind repair but not where it would create life‑safety hazards or conflict with CHBC conditions. See § 8-105.1 and § 8-303.7.
Skipping a structural survey or tests: For archaic structural materials, do the required investigation and have a licensed engineer assign allowable stresses per § 8-802 (and the referenced § 8-703).
Failing to consult the enforcing agency or SHBSB: When equivalency or alternatives are in question, get the enforcing agency’s acceptance or request SHBSB review per § 8-105.2 and § 8-104.2.
Mixing repair and alteration rules incorrectly: Repairs are allowed in greater latitude under Part 8; alterations (changing usability) are treated differently — confirm whether the work is a repair (renewal/reconstruction/renovation) as defined in CHBC. See definition Repair and § 8-105.1.

Worked example — parapet mortar and brick repair (with numbers)

Scenario: A qualified historic masonry building has a 10‑ft high, unreinforced brick parapet on a wall with thickness 10 inches. Mortar joints are failing and a contractor proposes repointing with a lime‑based mortar using original tooling (in‑kind repair).

Step 1 — Confirm CHBC applicability and repair status:

Parapet is on a qualified historic building and the work is a repair (renewal/repointing), so Part 8 applies. See § 8-102.1 and § 8-105.1.

Step 2 — Check life‑safety:

If the parapet is deemed capable of falling and creating a life‑safety hazard, repairs must mitigate that hazard; otherwise in‑kind repair is allowed per § 8-303.7 and § 8-803. Assume inspection shows no imminent falling hazard.

Step 3 — Structural evaluation / allowable strength:

For existing solid masonry (non‑adobe) the CHBC provides a default maximum ultimate shear strength of 9 psi under qualifying statements and conditions (unreinforced masonry where unsupported height/length to thickness ratio ≤ 13). If the parapet’s unsupported height (10 ft = 120 in) divided by thickness (10 in) = 12 → ≤ 13, so the guidance applies. See § 8-805.1.

Step 4 — Engineer and testing:

Have a structural survey and an evaluation by the project engineer per § 8-802 (and the survey procedures in § 8-703). The engineer may accept the 9 psi guidance or run tests to justify different allowable values.

Step 5 — Proceed with in‑kind repointing:

If the engineer and enforcing agency concur that repointing with lime mortar retains adequate strength and creates no life‑safety hazard, perform the in‑kind repointing. Document the materials/methods and retain records for the permit file. The owner may also submit alternative methods if desired under § 8-105.2.

In short: with a structural check, engineer assignment of allowable stresses, and enforcing agency concurrence (no life‑safety hazard), the proposed in‑kind lime repointing is allowed under § 8-105.1 and related sections.

Related provisions (useful to read)

§ 8-105.1 — Repairs (controlling permission for in‑kind repair).
§ 8-105.2 — Solutions to the CHBC (alternatives and equivalency).
§ 8-801.1 — Purpose of Chapter 8‑8: use of historical methods/materials.
§ 8-802 — General engineering approaches for archaic materials (testing, assigned stresses).
§ 8-803 — Nonstructural archaic materials (continued use if no hazard).
§ 8-804 — Allowable conditions for specific materials (evaluation required).
§ 8-805.1 — Existing solid masonry allowable shear guidance (example numeric limits).
§ 8-303.7 — Alteration and repair (limits tied to life‑safety hazards).
§ 8-102.1 — Application (when CHBC is used).
§ 8-104.2 — SHBSB review (appeals and statewide guidance).

Code references

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

CHBC § 8-104.4 High relevance — show source text
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.

SECTION 8-106 — SHBSB RULINGS

8-106.1 General. Rulings of the SHBSB (i.e., formal appeals, case decisions, code interpretations and administrative resolutions, etc.) that are issues of statewide application are required to be submitted to the California Building Standards Commission in printed form. These rulings may be used to provide guidance for similar cases or issues.

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8-2 DEFINITIONS

SECTION 8-201 — DEFINITIONS

For the purpose of the CHBC, certain terms and phrases, words and their derivatives shall be construed as specified in this chapter. Additional definitions and/or terms may appear in the various other chapters relative to terms or phrases primarily applicable thereto. Any reference to “authority having jurisdiction” does not necessarily preclude the appellate process of Section 8-104.3.

ADDITION. A nonhistorical extension or increase in floor area or height of a building or property.

ALTERATION. A modification to a qualified historical building or property that affects the usability of the building or property, or part thereof. Alterations include, but are not limited to, remodeling, renovation, rehabilitation, reconstruction, historical restoration, changes or rearrangement of the structural parts or elements, and changes or rearrangements in the plan configuration of walls and full-height partitions.

BUILDING STANDARD. Any guideline, regulation or code that may be applied to a qualified historical building or property.

CHARACTER-DEFINING FEATURE. Those visual aspects and physical elements that comprise the appearance of a historical building or property, and that are significant to its historical, architectural and cultural values, including the overall shape of the historical building or property, its materials, craftsmanship, decorative details, interior spaces and features, as well as the various aspects of its site and environment.

CULTURAL RESOURCE. Building, site, property, object or district evaluated as having significance in prehistory or history.
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 § 8-801 High 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.
CHBC § 8-303.6 High relevance — show source text
8-303.6 Light and ventilation. Windows in habitable rooms shall have an area of 6 percent of the floor area, or 6 square feet (0.56 m [2] ), whichever is greater. Windows in sleeping rooms shall be openable (see Section 8-503). Residential occupancies need not be provided with electrical lighting.

8-303.7 Alteration and repair. The alteration and repair of qualified historical buildings or properties may permit the replacement, retention and extension of original materials and the continued use of original methods of construction, provided a life safety hazard is not created or continued. Alterations and repairs shall be consistent with the CHBC.

The amount of alterations and repairs is not limited, provided there is no nonhistorical increase in floor area, volume or size of the building or property.

8-303.8 Exiting. See Chapter 8-5.

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8-4 FIRE PROTECTION

SECTION 8-401 — PURPOSE, INTENT AND SCOPE

8-401.1 Purpose. The purpose of this chapter is to provide regulations for fire protection of 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.

8-401.2 Intent. The intent of the CHBC is to preserve the integrity of qualified historical buildings or properties while maintaining a reasonable degree of fire protection based primarily on the life safety of the occupants and firefighting personnel.

8-401.3 Scope. This chapter shall apply when required by the provisions of Section 8-102.

SECTION 8-402 — FIRE-RESISTIVE CONSTRUCTION

8-402.1 Exterior wall construction. The fire-resistance requirement for existing exterior walls and existing opening protection may be satisfied when an automatic sprinkler system designed for exposure protection is installed per the CHBC. The automatic sprinklers may be installed on the exterior with at least one sprinkler located over each opening required to be protected. Additional sprinklers shall also be distributed along combustible walls under the roof lines that do not meet the fire-resistive requirement due to relationship to property lines as required by regular code. Such sprinkler systems may be connected to the domestic water supply on the supply-main side of the building shut-off valve. A shut-off valve may be installed for the sprinkler system, provided it is locked in an open position.

8-402.2 One-hour construction. Upgrading an existing qualified historical building or property to one-hour fire-resistive construction and one-hour fire-resistive corridors shall not be required regardless of construction or occupancy when one of the following is provided:
1. An automatic sprinkler system throughout. See Section 8-410 for automatic sprinkler systems.
2. An approved life safety evaluation.
3. Other alternative measures as approved by the enforcing agency.
8-402.3 Openings in fire-rated systems. Historical glazing materials and solid wood unrated doors in interior walls required to have one-hour fire rating may be approved when operable windows and doors are provided with appropriate smoke seals and when the area affected is provided with an automatic sprinkler system. See Section 8-410 for automatic sprinkler systems.

SECTION 8-403 — INTERIOR FINISH MATERIALS
CHBC § 8-302.6 High relevance — show source text
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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USE AND OCCUPANCY

8-303.5 Room dimensions. Rooms used for sleeping purposes may contain a minimum of 50 square feet (4.6 m [2] ) floor area, provided there is maintained an average ceiling height of 7 feet (2134 mm). Other habitable rooms need only be of adequate size to be functional for the purpose intended.

8-303.6 Light and ventilation. Windows in habitable rooms shall have an area of 6 percent of the floor area, or 6 square feet (0.56 m [2] ), whichever is greater. Windows in sleeping rooms shall be openable (see Section 8-503). Residential occupancies need not be provided with electrical lighting.

8-303.7 Alteration and repair. The alteration and repair of qualified historical buildings or properties may permit the replacement, retention and extension of original materials and the continued use of original methods of construction, provided a life safety hazard is not created or continued. Alterations and repairs shall be consistent with the CHBC.

The amount of alterations and repairs is not limited, provided there is no nonhistorical increase in floor area, volume or size of the building or property.

8-303.8 Exiting. See Chapter 8-5.

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8-4 FIRE PROTECTION

SECTION 8-401 — PURPOSE, INTENT AND SCOPE

8-401.1 Purpose. The purpose of this chapter is to provide regulations for fire protection of 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.

8-401.2 Intent. The intent of the CHBC is to preserve the integrity of qualified historical buildings or properties while maintaining a reasonable degree of fire protection based primarily on the life safety of the occupants and firefighting personnel.
CHBC § 401.1 High relevance — show source text
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4 REPAIRS

User notes:

About this chapter: Chapter 4 provides requirements for repairs of existing buildings. The provisions define conditions under which repairs may be made using materials and methods like those of the original construction or the extent to which repairs must comply with requirements for new buildings.

SECTION 401—GENERAL

401.1 Scope. R epairs shall comply with the requirements of this chapter. Repairs to historic buildings and structures shall comply with Part 8, Title 24, C.C.R. [OSHPD 1R, 2, 4 & 5] Repairs to historic buildings not adopted by OSHPD. Repairs shall comply with the requirements in the California Building Code, Sections 1224.2, 1225.2, 1226.2, 1227.2 and 1228.2 for functional requirements as applicable.

401.1.1 Bleachers, folding and telescopic seating and grandstands. Repairs to existing bleachers, folding and telescopic seating and grandstands shall comply with ICC 300.

401.1.2 Scope. [BSC] For state-owned buildings, including those owned by the University of California and the California State University and the Judicial Council, the requirements of Sections 405.2.1 and 405.2.3 are replaced by the requirements of Sections 317 through 322.

401.2 Compliance. The work shall not make the building less complying than it was before the repair was undertaken. Work on nondamaged components that is necessary for the required repair of damaged components shall be considered part of the repair and shall not be subject to requirements for alterations.

[BS] 401.3 Flood hazard areas. In flood hazard areas, repairs that constitute substantial improvement shall require that the building comply with Section 1612 of the California Building Code, or Section R306 of the California Residential Code, as applicable.

SECTION 402—BUILDING ELEMENTS AND MATERIALS

402.1 Glazing in hazardous locations. Replacement glazing in hazardous locations shall comply with the safety glazing requirements of the California Building Code or California Residential Code as applicable.

Exception: Glass block walls, louvered windows and jalousies repaired with like materials.

402.2 Existing materials. [HCD] Existing materials shall comply with Section 302.3.

402.3 New and replacement materials. [HCD & HCD 2] New and replacement materials used for repairs shall comply with Section 302.4.

SECTION 403—FIRE PROTECTION

403.1 General. Repairs shall be done in a manner that maintains the level of fire protection provided.

SECTION 404—MEANS OF EGRESS

404.1 General. Repairs shall be done in a manner that maintains the level of protection provided for the means of egress.

SECTION 405—STRUCTURAL

[BS] 405.1 General. Structural damage shall be repaired in compliance with this section and Section 401.2.

405.1.1 Structural concrete. Repair of structural concrete shall be permitted to comply with ACI 562 Section 1.7, except where Section 405.2.2, 405.2.3 or 405.2.4.1 requires compliance with Section 304.3.
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 § 323-9843 High relevance — show source text
State Librarian [SL]

library.ca.gov csllaw@library.ca.gov (916) 323-9843 Public Library Construction & Renovation

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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.
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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 § 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

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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 § 8-3 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.
CBC § 18955 High relevance — show source text
INTEGRITY. Authenticity of a building or property’s historical identity, evidenced by the survival of physical characteristics that existed during the property’s historical or prehistorical period of significance.

LIFE SAFETY EVALUATION. An evaluation of the life safety hazards of a qualified historical building or property based on procedures similar to those contained in NFPA 909, Standard for the Protection of Cultural Resources, Appendix B, Fire Risk Assessment in Heritage Premises.

LIFE SAFETY HAZARD. See Distinct Hazard.

PERIOD OF SIGNIFICANCE. The period of time when a qualified historical building or property was associated with important events, activities or persons, or attained the characteristics for its listing or registration.

PRESERVATION. The act or process of applying measures necessary to sustain the existing form, integrity and materials of a qualified historical building or property. Work, including preliminary measures to protect and stabilize the property, generally focuses upon the ongoing maintenance and repair of historic materials and features rather than extensive replacement and new construction. New exterior additions are not within the scope of this treatment; however, the limited and sensitive upgrading of mechanical,

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DEFINITIONS

electrical and plumbing systems and other code-related work to make properties functional is appropriate within a preservation project.

QUALIFIED HISTORICAL BUILDING OR PROPERTY. As defined in Health and Safety Code Section 18955 as “Qualified Historical Building or Property.” Any building, site, object, place, location, district or collection of structures, and their associated sites, deemed of importance to the history, architecture or culture of an area by an appropriate local, state or federal governmental jurisdiction. 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.
CHBC § 0.7 High relevance — show source text
For steel structural members, the deflection due to creep component of long-term dead load shall be permitted to be taken as zero.
h. For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroom additions or patio covers not supporting edge
of glass or aluminum sandwich panels, the total load deflection shall not exceed_l_/60. For continuous aluminum structural members supporting edge of glass, the total load
deflection shall not exceed_l_/175 for each glass lite or_l_/60 for the entire length of the member, whichever is more stringent. For aluminum sandwich panels used in roofs or
walls of sunroom additions or patio covers, the total load deflection shall not exceed_l_/120.
i._ l_ = Length of the member between supports. For cantilever members,l shall be taken as twice the length of the cantilever.
j. The snow load shall be permitted to be taken as 0.7 times the design snow load determined in accordance with Section 1608_A_.1 for the purpose of determining deflection
limits in Table 1604_A_.3.|For SI: 1 foot = 304.8 mm.
a. For structural roofing and siding made of formed metal sheets, the total load deflection shall not exceed_l_/60. For secondary roof structural members supporting formed
metal roofing, the live load deflection shall not exceed_l_/150. For secondary wall members supporting formed metal siding, the design wind load deflection shall not exceed
l/90. For roofs, this exception only applies when the metal sheets have no roof covering.
b. Flexible, folding and portable partitions are not governed by the provisions of this section. The deflection criterion for interior partitions is based on the horizontal load
defined in Section 1607_A_.16.
c. See Section 2403 for glass supports.
d. The deflection limit for the_D_ + (L or_Lr_) load combination only applies to the deflection due to the creep component of long-term dead load deflection plus the short-term live load
deflection. For lumber, structural glued laminated timber, prefabricated wood I-joists and structural composite lumber members that are dry at time of installation and used under
dry conditions in accordance with the ANSI/AWC NDS, the creep component of the long-term deflection shall be permitted to be estimated as the immediate dead load deflection
resulting from 0.5_D_. For lumber and glued laminated timber members installed or used at all other moisture conditions or cross laminated timber and wood structural panels that
are dry at time of installation and used under dry conditions in accordance with the ANSI/AWC NDS, the creep component of the long-term deflection is permitted to be estimated
as the immediate dead load deflection resulting from_D_. The value of 0.5_D_ shall not be used in combination with ANSI/AWC NDS provisions for long-term loading.
e. The preceding deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to ensure adequate drainage shall be investigated for ponding.
See Chapter 8 of ASCE 7.
f. The wind load shall be permitted to be taken as 0.42 times the “component and cladding” loads or directly calculated using the 10-year mean return interval basic wind
speed,V, for the purpose of determining deflection limits in Table 1604_A_.3. Where framing members support glass, the deflection limit therein shall not exceed that specified
in Section 1604_A_.3.7
g.

Frequently asked questions

Can I always use original materials even if they are weaker than modern materials?

Yes — but only if keeping or reusing those materials does not create a life‑safety or public health hazard, and the archaic materials are evaluated and assigned allowable stresses by the project engineer (or tested) with enforcing agency concurrence per § 8-802 and § 8-803.

What if the enforcing agency objects to my proposed in‑kind method?

You may submit the proposed alternative for evaluation; the CHBC allows alternatives that are reasonably equivalent and the SHBSB can be asked to review statewide issues per § 8-105.2 and § 8-104.2.

Do I need an engineer or tests to do simple repairs like window sash glazing?

Not always. Nonstructural historic features may remain if they do not create hazards. However, where structural capacity or specific allowable stresses matter you must document condition and, if required by § 8-802, obtain professional evaluation or testing. See § 8-803 and § 8-802.

If I add new materials to match historic fabric, is that still “in‑kind”?

Yes. The CHBC allows archaic materials to be reinstalled or installed with new materials of the same class to match existing conditions (Chapter 8‑8 scope). See § 8-801.3.

Who decides whether an in‑kind repair creates a life‑safety hazard?

The enforcing agency (local or state) determines life‑safety hazards; their concurrence is required when keeping archaic materials or methods might affect safety (see § 8-303.7 and § 8-803).

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Related in the CHBC

When will enforcing agencies accept alternatives or nonstandard solutions?

How are SHBSB rulings and statewide interpretations published and used?

Construction methods, materials, alternatives and SHBSB rulings

California Historical Building Code