CHBC · California Historical Building Code
When may the enforcing agency grant exceptions or accept equivalent alternatives to egress requirements?
For a homeowner with a qualified historic building: local code officials can allow some existing doors, stairs, and fire escapes to remain even if they don’t meet modern dimension rules — but only if the changes do not make the building less safe. The key test is whether life safety is adversely affected; specific CHBC limits (for example, a 29-inch minimum clear opening for fire-escape access and a 30-inch maximum sill) still apply unless a documented, reasonably equivalent alternative is approved.
Last reviewed: July 6, 2026
What the code requires
The enforcing agency must grant reasonable exceptions to specific egress provisions for qualified historic buildings when those exceptions will not adversely affect life safety — see § 8-502.1. The CHBC also directs the enforcing agency to accept reasonably equivalent alternatives to regular-code means-of-egress requirements where appropriate for preservation of historic significance (§ 8-501.1).
The single most important rule: the enforcing agency may allow deviations from regular egress dimensions or details for historic buildings only if the change does not make the building less safe for occupants. § 8-502.1.
Requirements in detail
Core authority and limit
- The enforcing agency is empowered to grant reasonable exceptions to specific egress provisions where the exception “will not adversely affect life safety” (§ 8-502.1) — this is the controlling standard.
- The CHBC frames this authority as complementary to the code’s preservation purpose: the CHBC requires accepting “reasonably equivalent alternatives” to regular-code egress rules when necessary to preserve historical significance (§ 8-501.1).
Common types of exceptions/examples preserved in the CHBC
The code lists specific, recurring egress conditions the enforcing agency may accept or allow to remain in historic buildings (these are examples, not an exhaustive list):
- Existing door openings and corridor widths smaller than regular-code dimensions are permitted where there is sufficient width and height for occupants to pass (§ 8-502.2).
- Existing stairs with riser/tread or width variances may remain if the enforcing agency determines they do not constitute a distinct hazard; nonconforming handrail grip size or extensions are allowed under the same determination (§ 8-502.3).
- Front/main entry doors need not be rehung to swing in the direction of exit travel if other means or conditions of exiting serve the occupant load (§ 8-502.4).
- Existing previously approved fire escapes and ladders may be accepted as one required means provided they extend to the ground, are easily negotiated, adequately signed and in good working order, and access is by an opening having at least 29 inches clear when open and a sill no higher than 30 inches above the floor/landing (§ 8-502.5).
- New fire escapes accepted under CHBC must meet specific minimums (clear opening 29 in, sill ≤ 30 in, stair pitch ≤ 72°, minimum width 18 in, live-load capacity 100 psf, handrails both sides, plus fire assembly protections where required) (§ 8-502.6).
Decision‑relevant dimensions and thresholds (quick reference)
| Decision factor | Key value / condition | Code reference |
|---|---|---|
| When exceptions allowed | Where exceptions will not adversely affect life safety | § 8-502.1 |
| Acceptance of equivalent alternatives | Accept reasonably equivalent alternatives to regular-code egress | § 8-501.1 |
| Door/corridor under-size | Permitted if sufficient width and height for passage | § 8-502.2 |
| Existing stairs nonconforming | Allowed if not a distinct hazard (agency determination) | § 8-502.3 |
| Main entry swing | Front/main doors need not swing with exit travel if other exits/conditions provided | § 8-502.4 |
| Existing fire escape access opening | Minimum clear opening 29 in when open; sill ≤ 30 in above floor | § 8-502.5 |
| New fire escape stair pitch | Maximum 72°; min width 18 in; live load 100 psf; clear opening 29 in | § 8-502.6 |
| Escape/rescue windows (sleeping rooms) | Min clear area 3.3 sq ft; min width/height 18 in; operable from inside | § 8-503 |
| Sprinklers and number of exits | Automatic sprinklers shall not substitute for or act as an alternate to the required number of exits. | § 8-410.3 |
Documentation & review expectations
- Alternatives or exceptions that affect accessibility or character-defining features require documentation and, in accessibility contexts, application item‑by‑item with retained records (§ 8-602.2, § 8-604) — see accessibility chapters for documentation expectations.
- For novel proposals the enforcing agency may request review or opinion from the State Historical Building Safety Board (SHBSB); the Board will determine whether a proposal is reasonably equivalent and report its findings to the enforcing agency (§ 8-104.2).
- The CHBC expects alternatives offered in lieu of its provisions to be reasonably equivalent in quality, strength, effectiveness, durability and safety; the enforcing agency may require evidence to substantiate claims (§ 8-105.2).
Exceptions & special cases
- Accessibility tradeoffs: when strict application of regular accessibility provisions would threaten or destroy historical significance, the CHBC allows item‑by‑item alternatives or equivalent facilitation, but they must be documented and provide substantially equivalent access where feasible (§ 8-602.1, § 8-603, § 8-604). These are accessibility-specific parallels to egress exception rules and often run in parallel during plan review.
- Life‑safety ceiling: the CHBC cannot be used to permit changes that would produce an unacceptable life‑safety risk in critical public-safety occupancies (see other CHBC chapters for structural exceptions limits) — agency judgement remains central (§ 8-702.1 indicates limits for structural safety in certain occupancies).
- Fire protection vs. exits: installing sprinklers may relax some fire-resistive upgrade requirements under the CHBC, but per § 8-410.3 sprinklers do not substitute for the required number of exits.
Common mistakes
- Assuming exceptions are automatic. The CHBC gives authority to grant exceptions, but the standard is safety — exceptions must be justified and documented (§ 8-502.1; documentation requirements elsewhere).
- Ignoring explicit CHBC minimums. For example, relying on § 8-502.2 (allowing undersized doors) to override the explicit 29 in access-opening requirement for fire-escape access under § 8-502.5 is incorrect — the code gives specific dimensions for some historic features and those must be met unless a justified alternative is documented.
- Treating sprinklers as a substitute for exits. Sprinklers improve fire protection but do not replace the required number of exits (§ 8-410.3).
- Failing to use the SHBSB when appropriate. For unusual or statewide-significant equivalencies, the enforcing agency (or applicant) can seek SHBSB review per § 8-104.2; skipping that step risks inconsistent outcomes.
Worked example — boarding house fire escape scenario
Scenario: A two-story qualified historic boarding house has an existing external fire-escape balcony and ladder that was previously approved. The access opening from the corridor to the fire escape is 30 inches clear when open; the sill is 28 inches above the landing. The building owner proposes to retain that escape as the second required means of egress.
How the enforcing agency applies the CHBC:
- Identify controlling provisions: § 8-502.1 (exceptions allowed if life safety not adversely affected) and the specific fire-escape acceptance clause § 8-502.5 (access opening min 29 in, sill ≤ 30 in).
- Compare dimensions to CHBC specifics: the existing 30 in clear opening meets the 29 in minimum and the 28 in sill satisfies the ≤ 30 in requirement of § 8-502.5.
- Inspect condition and usability: verify the escape extends to the ground, is easily negotiated, adequately signed, and in good working order as required by § 8-502.5. If the ladder is rusted or handholds are loose, the agency may require repairs or reject acceptance.
- Outcome: If the agency determines the escape is in good working order and presents no distinct hazard to life safety, it may accept the fire escape as one of the required means without forcing a full-code retrofit. Document the decision and retain records per CHBC practice; if the proposal raised novel questions, the enforcing agency could request SHBSB review under § 8-104.2.
Note: if the access opening had been 28 in, it would not meet the explicit 29 in limit in § 8-502.5, and the agency would need to identify an alternative that provides equivalent safety or require modification.
Related provisions
- § 8-501.1 — Purpose: accept reasonably equivalent alternatives to regular-code means of egress.
- § 8-502.2 — Existing door openings and corridor widths.
- § 8-502.3 — Existing stairs and handrails variance.
- § 8-502.4 — Main entry doors swing exceptions.
- § 8-502.5 — Existing fire escapes acceptance (29 in / 30 in sill).
- § 8-502.6 — Requirements for new fire escapes and ladders.
- § 8-503 — Escape or rescue windows and doors (dimensions for sleeping rooms).
- § 8-410.3 — Sprinklers shall not substitute for required number of exits.
- § 8-104.2 — SHBSB review and process for evaluating alternatives.
- § 8-105.2 — Requirement that alternatives be reasonably equivalent in quality/effectiveness.
- § 8-602.2 / § 8-603 / § 8-604 — Accessibility alternative provisions and documentation expectations (apply where accessibility tradeoffs intersect egress solutions).
Code references
Grounded in the retrieved California Historical Building Code — click a citation to read the verbatim passage:
CHBC § 8-5 High relevance — show source text
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8-5 MEANS OF EGRESS
SECTION 8-501 — PURPOSE, INTENT AND SCOPE
8-501.1 Purpose. The purpose of this chapter is to establish minimum means of egress regulations for qualified historical buildings or properties. The CHBC requires enforcing agencies to accept reasonably equivalent alternatives to the means of egress requirements in the regular code.
8-501.2 Intent. The intent of these regulations is to provide an adequate means of egress.
8-501.3 Scope. Every qualified historical building or portion thereof shall be provided with exits as required by the CHBC when required by the provisions of Section 8-102.
SECTION 8-502 — GENERAL
8-502.1 General. The enforcing agency shall grant reasonable exceptions to the specific provisions of applicable egress regulations where such exceptions will not adversely affect life safety.
8-502.2. Existing door openings and corridor widths of less than dimensions required by regular code shall be permitted where there is sufficient width and height for the occupants to pass through the opening or traverse the exit.
8-502.3 Stairs. Existing stairs having risers and treads or width at variance with the regular code are allowed if determined by the enforcing agency to not constitute a distinct hazard. Handrails with nonconforming grip size or extensions are allowed if determined by the enforcing agency to not constitute a distinct hazard.
8-502.4 Main entry doors. The front or main entry doors need not be rehung to swing in the direction of exit travel, provided other means or conditions of exiting, as necessary to serve the total occupant load, are provided.
8-502.5 Existing fire escapes. Existing previously approved fire escapes and fire escape ladders shall be acceptable as one of the required means of egress, provided they extend to the ground and are easily negotiated, adequately signed and in good working order. Access shall be by an opening having a minimum width of 29 inches (737 mm) when open with a sill no more than 30 inches (762 mm) above the adjacent floor, landing or approved step.
8-502.6 New fire escapes and fire escape ladders. New fire escapes and fire escape ladders which comply with this section shall be acceptable as one of the required means of egress. New fire escapes and new fire escape ladders shall comply with the following:
- Access from a corridor shall not be through an intervening room.
- All openings within 10 feet (3048 mm) shall be protected by three-fourths-hour fire assemblies. When located within a recess or vestibule, adjacent enclosure walls shall be of not less than one-hour fire-resistive construction.
- Egress from the building shall be by a clear opening having a minimum dimension of not less than 29 inches (737 mm). Such openings shall be openable from the inside without the use of a key or special knowledge or effort. The sill of an opening giving access shall not be more than 30 inches (737 mm) above the floor, step or landing of the building or balcony.
- Fire escape stairways and balconies shall support the dead load plus a live load of not less than 100 pounds per square foot (4.79 kN/m [2] ) and shall be provided with a top and intermediate handrail on each side. The pitch of the stairway shall not exceed 72 degrees with a minimum width of 18 inches (457 mm).
CHBC § 8-410.3 High relevance — show source text
Buildings with floors above 75 feet, NFPA 13.
When the building is free standing or with property line separation, two floors and 1500 square feet per floor or less, NFPA 13D.
For exterior wall and opening protection. As required by this chapter.
Exception: When the automatic sprinkler systems are used to reach compliance using this code, in three or more occasions, NFPA 13D standard shall be increased to NFPA 13R standard, or NFPA 13R standard shall be increased to a NFPA 13 standard.
8-410.3 Automatic sprinkler systems shall not be used to substitute for or act as an alternate to the required number of exits from any facility. (See Chapter 8-5 for exiting requirements.)
8-410.4 An automatic sprinkler system shall be provided in all detention facilities.
SECTION 8-411 — OTHER TECHNOLOGIES
Fire alarm systems, smoke and heat detection systems, occupant notification and annunciation systems, smoke control systems and fire modeling, timed egress analysis and modeling, as well as other engineering methods and technologies may be accepted by the enforcing agency to address areas of nonconformance.
SECTION 8-412 — HIGH-RISE BUILDINGS
Qualified historical buildings having floors for human occupancy located more than 75 feet above the lowest floor level having building access shall conform to the provisions of the regular code for existing high-rise buildings as amended by the CHBC.
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8-5 MEANS OF EGRESS
SECTION 8-501 — PURPOSE, INTENT AND SCOPE
8-501.1 Purpose. The purpose of this chapter is to establish minimum means of egress regulations for qualified historical buildings or properties. The CHBC requires enforcing agencies to accept reasonably equivalent alternatives to the means of egress requirements in the regular code.
8-501.2 Intent. The intent of these regulations is to provide an adequate means of egress.
8-501.3 Scope. Every qualified historical building or portion thereof shall be provided with exits as required by the CHBC when required by the provisions of Section 8-102.
SECTION 8-502 — GENERAL
8-502.1 General. The enforcing agency shall grant reasonable exceptions to the specific provisions of applicable egress regulations where such exceptions will not adversely affect life safety.
8-502.2. Existing door openings and corridor widths of less than dimensions required by regular code shall be permitted where there is sufficient width and height for the occupants to pass through the opening or traverse the exit.
8-502.3 Stairs. Existing stairs having risers and treads or width at variance with the regular code are allowed if determined by the enforcing agency to not constitute a distinct hazard. Handrails with nonconforming grip size or extensions are allowed if determined by the enforcing agency to not constitute a distinct hazard.
8-502.4 Main entry doors. The front or main entry doors need not be rehung to swing in the direction of exit travel, provided other means or conditions of exiting, as necessary to serve the total occupant load, are provided.
CHBC § 8-604 High relevance — show source text
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ACCESSIBILITY
SECTION 8-604 — EQUIVALENT FACILITATION
Use of other designs and technologies, or deviation from particular technical and scoping requirements, are permitted if the application of the alternative provisions contained in Section 8-603 would threaten or destroy the historical significance or characterdefining features of the historical building or property.
- Such alternatives shall be applied only on an item-by- item or a case-by-case basis.
- Access provided by experiences, services, functions, materials and resources through methods including, but not limited to, maps, plans, videos, virtual reality and related equipment, at accessible levels. The alternative design and/or technologies used will provide substantially equivalent or greater accessibility to, and usability of, the facility.
- The official charged with the enforcement of the standards shall document the reasons for the application of the design and/or technologies and their effect on the historical significance or character-defining features. Such documentation shall be in accordance with Section 8-602.2, Item 2, and shall include the opinion and comments of state or local accessibility officials, and the opinion and comments of representative local groups of people with disabilities. Such documentation shall be retained in the permanent file of the enforcing agency. Copies of the required documentation should be available at the facility upon request.
Note: For commercial facilities and places of public accommodation (Title III entities).
Equivalent facilitation for an element of a building or property when applied as a waiver of an ADA accessibility requirement will not be entitled to the Federal Department of Justice certification of this code as rebuttable evidence of compliance for that element.
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8-7 STRUCTURAL REGULATIONS
SECTION 8-701 — PURPOSE, INTENT AND SCOPE
8-701.1 Purpose. The purpose of the CHBC is to provide alternative regulations to the regular code for the structural safety of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.
8-701.2 Intent. The intent of this chapter is to encourage the preservation of qualified historical buildings or structures while providing standards for a minimum level of building performance with the objective of preventing partial or total structural collapse such that the overall risk of life-threatening injury as a result of structural collapse is low.
8-701.3 Application. The alternative structural regulations provided by Section 8-705 are to be applied in conjunction with the regular code whenever a structural upgrade or reconstruction is undertaken for qualified historical buildings or properties.
SECTION 8-702 — GENERAL
8-702.1 The CHBC shall not be construed to allow the enforcing agency to approve or permit a lower level of safety of structural design and construction than that which is reasonably equivalent to the regular code provisions in occupancies which are critical to the safety and welfare of the public at large, including, but not limited to, public and private schools, hospitals, municipal police and fire stations and essential services facilities.
8-702.2 Nothing in these regulations shall prevent voluntary and partial seismic upgrades when it is demonstrated that such upgrades will improve life safety and when a full upgrade would not otherwise be required.
CHBC § 8-801 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 § 8-302.6 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 § 8-7 High relevance — show source text
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8-7 STRUCTURAL REGULATIONS
SECTION 8-701 — PURPOSE, INTENT AND SCOPE
8-701.1 Purpose. The purpose of the CHBC is to provide alternative regulations to the regular code for the structural safety of buildings designated as qualified historical buildings or properties. The CHBC requires enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.
8-701.2 Intent. The intent of this chapter is to encourage the preservation of qualified historical buildings or structures while providing standards for a minimum level of building performance with the objective of preventing partial or total structural collapse such that the overall risk of life-threatening injury as a result of structural collapse is low.
8-701.3 Application. The alternative structural regulations provided by Section 8-705 are to be applied in conjunction with the regular code whenever a structural upgrade or reconstruction is undertaken for qualified historical buildings or properties.
SECTION 8-702 — GENERAL
8-702.1 The CHBC shall not be construed to allow the enforcing agency to approve or permit a lower level of safety of structural design and construction than that which is reasonably equivalent to the regular code provisions in occupancies which are critical to the safety and welfare of the public at large, including, but not limited to, public and private schools, hospitals, municipal police and fire stations and essential services facilities.
8-702.2 Nothing in these regulations shall prevent voluntary and partial seismic upgrades when it is demonstrated that such upgrades will improve life safety and when a full upgrade would not otherwise be required.
SECTION 8-703 — STRUCTURAL SURVEY
8-703.1 Scope. When a structure or portion of a structure is to be evaluated for structural capacity under the CHBC, it shall be surveyed for structural conditions by an architect or engineer knowledgeable in historical structures. The survey shall evaluate deterioration or signs of distress. The survey shall determine the details of the structural framing and the system for resistance of gravity and lateral loads. Details, reinforcement and anchorage of structural systems and veneers shall be determined and documented where these members are relied on for seismic lateral resistance.
8-703.2 The results of the survey shall be utilized for evaluating the structural capacity and for designing modifications to the structural system to reach compliance with this code.
8-703.3 Historical records. Past historical records of the structure or similar structures may be used in the evaluation, including the effects of subsequent alterations.
SECTION 8-704 — NONHISTORICAL ADDITIONS AND NONHISTORICAL ALTERATIONS
8-704.1 New nonhistorical additions and nonhistorical alterations which are structurally separated from an existing historical building or structure shall comply with regular code requirements.
8-704.2 New nonhistorical additions which impose vertical or lateral loads on an existing structure shall not be permitted unless the affected part of the supporting structure is evaluated and strengthened, if necessary, to meet regular code requirements.
Note: For use of archaic materials, see Chapter 8-8.
SECTION 8-705 — STRUCTURAL REGULATIONS
CHBC § 8-901.5 High relevance — show source text
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.
8-902.3 Fuel oil piping and tanks. Fuel oil piping and tanks shall comply with regular code requirements except that the enforcing agency may waive such requirements where the lack of compliance does not create a safety or environmental hazard.
8-902.4 Heat-producing and cooling equipment. Heat-producing and cooling equipment shall comply with the regular code requirements governing equipment safety, except that the enforcing agency may accept alternatives which do not create a safety hazard.
8-902.5 Combustion air.
8-902.5.1 All fuel-burning appliances and equipment shall be provided a sufficient supply of air for proper fuel combustion, ventilation and draft hood dilution.
8-902.5.2 The enforcing agency may require operational tests for combustion air systems which do not comply with applicable requirements of the regular code.
8-902.6 Venting of appliances.
8-902.6.1 Every appliance required to be vented shall be connected to an approved venting system. Venting systems shall develop a positive flow adequate to convey all combustion products to the outside atmosphere.
8-902.6.2 Masonry chimneys in structurally sound condition may remain in use for all fuel-burning appliances, provided the flue is evaluated and documentation provided that the masonry and grout are in good condition. Terra cotta chimneys and Type C metallic vents installed in concealed spaces shall not remain in use unless otherwise mitigated and approved on a case-by-case basis.
8-902.6.3 The enforcing agency may require operational tests for venting systems which do not comply with applicable requirements of the regular code.
8-902.7 Ducts.
8-902.7.1 New ducts shall be constructed and installed in accordance with applicable requirements of the regular code.
8-902.7.2 Existing duct systems which do not comply with applicable requirements of the regular code and do not, in the opinion of the enforcing agency, constitute a safety or health hazard may remain in use.
8-902.8 Ventilating systems.
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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:
- An automatic sprinkler system throughout. See Section 8-410 for automatic sprinkler systems.
- An approved life safety evaluation.
- 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 § 17.2.5.4. High relevance — show source text
3. Special reinforced concrete moment frames—Not permitted by OSHPD.
Exceptions: 1. Systems listed in this section can be used as an alternative system when preapproved by the enforcement agency. 2. Rooftop or other supported structures not exceeding two stories in height and 10 percent of the total structure weight can use the systems in this section when designed as components per ASCE 7, Chapter 13. 3. Systems listed in this section can be used for seismically isolated buildings, when permitted by ASCE 7, Section 17.2.5.4.
1617A.1.5 Reserved.
1617A.1.6 Reserved.
1617A.1.7 ASCE 7, Section 12.2.5.6.1 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
1617A.1.8 ASCE 7, Section 12.2.5.7.1 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
1617A.1.9 ASCE 7, Section 12.2.5.7.2 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.
1617A.1.10 ASCE 7, Section 12.3.3.1. Replace ASCE 7, Section 12.3.3.1 by the following:
12.3.3.1 Prohibited vertical irregularities for Seismic Design Categories D through F. Structures assigned to Seismic Design Category D, E or F that have vertical irregularities Type 1b, 4a or 4b of Table 12.3-2 shall not be permitted.
Exception: Structures assigned to Seismic Design Category D, E or F that have vertical irregularity Type 4a shall be permitted where the story lateral strength is not less than 80% of that in the story above.
1617A.1.11 ASCE 7, Section 12.7.2. Modify ASCE 7, Section 12.7.2, by adding Item 7 to read as follows: 7. Where buildings provide lateral support for walls retaining earth, and the exterior grades on opposite sides of the building differ by more than 6 feet (1829 mm), the load combination of the seismic increment of earth pressure due to earthquake acting on the higher side, as determined by a geotechnical engineer qualified in soils engineering plus the difference in earth pressures shall be added to the lateral forces provided in this section.
1617A.1.12 ASCE 7, Section 12.10.2.1. Replace Exception to ASCE 7, Section 12.10.2.1 by the following:
Exception: In light-frame structures or portions thereof braced entirely by wood light-frame shear walls, collector elements and their connections, including connections to vertical elements, need only be designed to resist forces using the load combinations of Section 2.3.6 with seismic forces determined in accordance with Section 12.10.1.1.
1617A.1.13 ASCE 7, Section 12.13.5.2. Modify ASCE 7, Section 12.13.5.2 by the following:
CHBC § 8-9 Medium 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
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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 § 8-603.2 Medium relevance — show source text
8-603.2 Entry. These alternatives do not allow exceptions for the requirement of level landings in front of doors, except as provided in Section 8-603.4.
- Access to any entrance used by the general public and no further than 200 feet (60 960 mm) from the primary entrance.
- Access at any entrance not used by the general public but open and unlocked with directional signs at the primary entrance and as close as possible to, but no further than 200 feet (60 960 mm) from, the primary entrance.
- The accessible entrance shall have a notification system. Where security is a problem, remote monitoring may be used.
8-603.3 Doors. Alternatives listed in order of priority are:
- Single-leaf door which provides a minimum 30 inches (762 mm) of clear opening.
- Single-leaf door which provides a minimum 29 [1] / 2 inches (749 mm) clear opening
- Double door, one leaf of which provides a minimum 29 [1] / 2 inches (749 mm) clear opening.
- Double doors operable with a power-assist device to provide a minimum 29 [1] / 2 inches (749 mm) clear opening when both doors are in the open position.
8-603.4 Power-assisted doors. Power-assisted door or doors may be considered an equivalent alternative to level landings, strikeside clearance and door-opening forces required by the regular code.
8-603.5 Toilet rooms. In lieu of separate-gender toilet facilities as required in the regular code, an accessible unisex toilet facility may be designated.
8-603.6 Exterior and interior ramps and lifts. Alternatives listed in order of priority are:
- A lift or a ramp of greater than standard slope but no greater than 1:10, for horizontal distances not to exceed 5 feet (1525 mm). Signs shall be posted at upper and lower levels to indicate steepness of the slope.
- Access by ramps of 1:6 slope for horizontal distance not to exceed 13 inches (330 mm). Signs shall be posted at upper and lower levels to indicate steepness of the slope.
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ACCESSIBILITY
SECTION 8-604 — EQUIVALENT FACILITATION
Use of other designs and technologies, or deviation from particular technical and scoping requirements, are permitted if the application of the alternative provisions contained in Section 8-603 would threaten or destroy the historical significance or characterdefining features of the historical building or property.
- Such alternatives shall be applied only on an item-by- item or a case-by-case basis.
- Access provided by experiences, services, functions, materials and resources through methods including, but not limited to, maps, plans, videos, virtual reality and related equipment, at accessible levels. The alternative design and/or technologies used will provide substantially equivalent or greater accessibility to, and usability of, the facility.
- The official charged with the enforcement of the standards shall document the reasons for the application of the design and/or technologies and their effect on the historical significance or character-defining features. Such documentation shall be in accordance with Section 8-602.2, Item 2, and shall include the opinion and comments of state or local accessibility officials, and the opinion and comments of representative local groups of people with disabilities. Such documentation shall be retained in the permanent file of the enforcing agency.
CHBC § 3A-9 Medium relevance — show source text
305 A .1 General. Where used, in-situ load tests shall be conducted in accordance with Section 1708 A of the California Building Code .
SECTION 306 A —ACCESSIBILITY FOR EXISTING BUILDINGS
306 A .1 Scope. Accessibility requirements for existing buildings shall comply with the California Building Code, Part 2, Volume 1, Chapter 11B.
SECTION 307 A —SMOKE ALARMS
Shall comply with the California Building Standards Code.
SECTION 308 A —CARBON MONOXIDE DETECTION
Shall comply with the California Building Standards Code.
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PROVISIONS FOR ALL COMPLIANCE METHODS
SECTION 309 A — RESERVED
SECTION 310A — COMPLIANCE ALTERNATIVES FOR SERVICES/SYSTEMS AND UTILITIES
310A.1 General. The provisions of this section are intended to maintain or increase the current degree of public safety, health and general welfare in existing buildings while permitting repair, alteration, addition and change of occupancy without requiring full compli- ance with California Building Code Chapters 2 through 33, or Sections 302A.3 and 502A through 506A, except where compliance with other provisions of this code is specifically required in this section.
Services/systems and utilities that originate in and pass through or under buildings and are necessary to the operation of the hospital buildings shall meet the structural requirements of this section. Examples of services/systems and utilities include but are not limited to normal power; emergency power; nurse call; fire alarm; communication and data systems; space-heating systems; process load systems; cooling systems; domestic hot and cold water systems; means of egress systems; fire-suppression systems; building drain and sewer systems; and medical gas systems that support basic and supplemental services.
After January 1, 2030, services/systems and utilities for acute care hospital buildings shall not originate in or pass through or under a nonhospital or hospital building unless it has approved performance categories of SPC-3 or higher and NPC-5.
310A.1.1 Services/systems and utilities. Services/systems and utilities that are necessary to the operation of the hospital buildings shall meet the structural requirements of this section, based upon the approved Structural Performance Category (SPC) of the build- ing receiving the services/systems and utilities.
Services from a conforming building shall be permitted to serve a nonconforming building with prior approval of the Office. The services/systems and utilities in the nonconforming building shall be equipped with fail safe valves, switches or other equivalent devices that allow the nonconforming building to be isolated from the conforming building.
Exception: Remodel projects that use available existing services/systems and utilities are exempted from the requirements of this section. The enforcing agency shall be permitted to exempt minor addition, minor alteration and minor remodel projects and proj- ects to upgrade existing services/systems and utilities from the requirements of this section.
310A.1.1.1 Services/systems and utilities for hospital buildings.
Frequently asked questions
When is an enforcing agency allowed to refuse an exception to egress requirements?
If allowing the exception would adversely affect life safety or create a distinct hazard, the enforcing agency must refuse. The CHBC’s threshold is safety — see § 8-502.1.
Do automatic sprinklers let me reduce the number of exits?
No. Per § 8-410.3 automatic sprinkler systems shall not be used to substitute for or act as an alternate to the required number of exits.
What documentation is needed when an alternative is proposed?
The CHBC expects the enforcing agency to retain documentation showing why the alternative was used and how it preserves life safety; accessibility alternatives require item‑by‑item documentation and retention in the agency file (§ 8-602.2, § 8-604).
If the enforcing agency and applicant disagree, can the SHBSB be asked to review?
Yes — the enforcing agency or any person affected may request SHBSB review; the Board will determine whether the proposal is reasonably equivalent for the intended purpose (§ 8-104.2).
Are there numeric minimums I must meet for existing fire escape access?
Yes. The CHBC requires an access opening minimum clear width of 29 inches when open and a sill no more than 30 inches above the floor/landing for existing approved fire escapes to count as required egress (§ 8-502.5).
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