CHBC · California Historical Building Code

How do alteration/repair rules and exiting apply to historic residential occupancies?

Homeowners: CHBC lets you repair or alter historic homes using original materials and methods so long as you don’t create or continue a life‑safety hazard (see § 8‑303.7). Basements and sleeping rooms need an openable escape window/door meeting the dimensions in § 8‑503 (3.3 sq ft clear, 18 in min), and fire escapes are governed by Chapter 8‑5 (see § 8‑303.4 and § 8‑502). Always confirm proposed changes with your enforcing agency because the CHBC accepts alternatives only when life‑safety is preserved.

Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

In plain English: the CHBC lets owners repair and alter qualified historical residential buildings using original materials and methods so long as those actions do not create or continue a life safety hazard and are consistent with the CHBC. See § 8-303.7 for the alteration/repair rule. Exiting for residential units (including escape windows and use of fire escapes) is governed by Chapter 8-5; see § 8-303.4 and the specific escape-opening dimensions in § 8-503.

The single most important rule: Alterations and repairs may preserve original materials and methods, but never if they create or continue a life safety hazard (see § 8-303.7).


Requirements in detail

Alteration & Repair — what is allowed

  • The CHBC permits replacement, retention and extension of original materials and continued use of original methods of construction for qualified historic buildings — provided a life safety hazard is not created or continued. See § 8-303.7.
  • There is no numerical limit on the amount of alterations or repairs in CHBC so long as there is no nonhistorical increase in floor area, volume, or size of the building or property. See § 8-303.7.

Exiting — which provisions apply for residential units

  • For exiting specifics the CHBC points residential occupancies to Chapter 8-5 (means of egress). See § 8-303.4.
  • Escape/opening requirements for basements and sleeping rooms are explicit in § 8-503: at least one openable window or door that opens directly to a public street/way/yard/exit court; must be operable from inside without special tools.

Decision-relevant dimensions & thresholds

Decision factor Value / threshold When it matters Code Reference
Allowed to use original materials & methods Permitted unless a life safety hazard is created/continued Any repair or alteration to a qualified historical residential building § 8-303.7
Limit on amount of repair/alteration No explicit numeric limit provided So long as there is no nonhistorical increase in floor area/volume/size § 8-303.7
Escape / rescue window minimum clear area 3.3 sq ft (0.31 m2) Basements and every sleeping room below the fourth floor § 8-503
Escape window min width or height 18 inches (457 mm) Same as above — window must meet at least one of these minimums and the clear area § 8-503
Escape window operability Operable from inside without special tools Same as above § 8-503
Existing fire-escape access opening min width 29 inches (737 mm) when open Where existing approved fire escapes are used as a required means of egress § 8-502.5
Sill height for fire-escape access/opening ≤ 30 inches (762 mm) above floor/landing Access to existing fire escape per § 8-502.5 § 8-502.5

(Each table entry is taken directly from the CHBC provisions cited.)


Exceptions & special cases

  • Existing historic elements that do not meet regular-code dimensions may be left in place if the enforcing agency determines they do not constitute a distinct hazard (CHBC allows reasonable exception). See § 8-502.1–.3 (general egress allowances).
  • Existing approved fire escapes may be accepted as one of the required means of egress provided they extend to the ground, are easily negotiated, adequately signed and in good working order; access opening must meet the minimums in § 8-502.5.
  • New fire escapes are allowed but must comply with the CHBC's specific new-fire-escape criteria (access, fire protection around openings, capacity and railing requirements). See § 8-502.6.
  • Alterations that cause a nonhistorical increase in floor area/volume/size are not covered by the “no limit” language; nonhistorical additions must conform to the regular code per § 8-102.1.1.

Common mistakes

  • Assuming CHBC allows unlimited change: CHBC allows extensive repair/alteration but not a nonhistorical increase in floor area/volume/size — that is restricted. See § 8-303.7 and § 8-102.1.1.
  • Forgetting escape-opening clear area: measuring glass size instead of the clear operable opening — the minimum clear area is 3.3 sq ft and 18 in minimum height or width per § 8-503.
  • Replacing historical windows without checking egress: swapping to historically sympathetic fixed glazing that reduces operable clear opening could violate § 8-503 for sleeping rooms.
  • Treating the CHBC as identical to regular code: CHBC intentionally allows alternatives and retention of historic features unless a life-safety hazard exists — but you must document and coordinate with enforcing agency. See § 8-101 and § 8-303.7.

Worked example — concrete scenario with numbers

Scenario: A homeowner owns a two‑story qualified historic house with a basement bedroom and wants to replace an original single‑hung window with a historically sympathetic new unit.

  1. Code check for basement sleeping room egress: § 8-503 requires at least one openable emergency escape window/door with a minimum clear area of 3.3 sq ft and a minimum width or height of 18 in, operable from the inside without special tools.

  2. Practical measurement: the proposed replacement window provides a clear operable opening of 20 in × 40 in = 800 in². Convert: 800 in² ÷ 144 = 5.56 ft² clear area. That exceeds the 3.3 ft² requirement and both dimensions exceed 18 in, so the opening meets § 8-503.

  3. CHBC alteration permissibility: Replacing the window with this new operable unit is allowed under § 8-303.7 because the owner is replacing an original element with a compatible unit and the change does not create a life safety hazard — in fact it improves egress. No limit on repair scope applies here because there is no nonhistorical increase in floor area/volume.

  4. If the owner instead attempted to enlarge the basement so the house footprint increased (a nonhistorical increase in floor area), that enlargement would not be covered by the “no limit” allowance and the nonhistorical addition would need to conform to the regular code per § 8-102.1.1.


Related provisions (quick list)

  • § 8-303.7 — Alteration and repair (controlling text on using original materials/methods; no increase unless historical).
  • § 8-303.4 — Fire escapes: directs residential occupancies to Chapter 8-5 (means of egress).
  • § 8-503 — Escape or rescue windows and doors (minimum clear area and dimensions).
  • § 8-502.5–.6 — Existing and new fire escape requirements (access width, sill height, structural/load and guarding).
  • § 8-302.4 — Maximum floor area exceptions (sprinkler / exiting exceptions for residential occupancies).
  • § 8-101 / § 8-102 — CHBC scope, intent and application of alternatives vs. the regular code.

Code references

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

  • 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 § 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 § 8-102.1.1 High relevance — show source text
    1. State agencies. All state agencies shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, rehabilitation, safety, relocation, reconstruction or continued use of qualified historical buildings or properties.

    8-102.1.1 Additions, alterations and repairs. It is the intent of the CHBC to allow nonhistorical expansion or addition to a qualified historical building or property, provided nonhistorical additions shall conform to the requirements of the regular code (as defined in Chapter 8-2).

    8-102.1.2 Relocation. Relocated qualified historical buildings or properties shall be sited to comply with the regular code or with the solutions listed in the CHBC. Nonhistorical new construction related to relocation shall comply with the regular code. Reconstruction and restoration related to relocation is permitted to comply with the provisions in the CHBC.

    8-102.1.3 Change of occupancy. For change of use or occupancy, see Chapter 8-3, Use and Occupancy.

    8-102.1.4 Continued use. Qualified historical buildings or properties may have their existing use or occupancy continued if such use or occupancy conformed to the code or to the standards of construction in effect at the time of construction, and such use or occupancy does not constitute a distinct hazard to life safety as defined in the CHBC.

    8-102.1.5 Unsafe buildings or properties. When a qualified historical building or property is determined to be unsafe as defined in the regular code, the requirements of the CHBC are applicable to the work necessary to correct the unsafe conditions. Work to remediate the buildings or properties need only address the correction of the unsafe conditions, and it shall not be required to bring the entire qualified historical building or property into compliance with regular code.

    8-102.1.6 Additional work. Qualified historical buildings or properties shall not be subject to additional work required by the regular code, regulation or ordinance beyond that required to complete the work undertaken. Certain exceptions for accessibility and for distinct hazards exist by mandate and may require specific action, within the parameters of the CHBC.

    SECTION 8-103 ORGANIZATION AND ENFORCEMENT

    8-103.1 Authority. The state or local enforcing agency, pursuant to authority provided under Section 18954 of the Health and Safety Code, shall administer and enforce the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, reconstruction, rehabilitation, relocation or continued use of a qualified historical building or property.

    8-103.2 State enforcement. All state agencies pursuant to authority provided under Section 18954 and Section 18961 of the Health and Safety Code shall administer and enforce the CHBC with respect to qualified historical buildings or properties under their respective jurisdiction.

    8-103.3 Liability. Prevailing law regarding immunity of building officials is unaffected by the use and enforcement of the CHBC.

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    ADMINISTRATION

    SECTION 8-104 REVIEW AND APPEALS

    8-104.1 State Historical Building Safety Board (SHBSB or Board). In order to provide for interpretation of the provisions of the CHBC and to hear appeals, the SHBSB shall act as an appeal and review body to state and local agencies or any affected party.

    **8-104.2 SHBSB review.

  • CHBC § 2.1. High relevance — show source text

    [RB] STRUCTURE. That which is built or constructed.

    [RB] SUBSOIL DRAIN. A drain that collects subsurface water or seepage water and conveys such water to a place of disposal.

    [RB] SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its beforedamaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

    [RB] SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, alteration, addition or other improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

    1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
    2. Any alteration of a historic structure provided that the alteration will not preclude the structure’s continued designation as a historic structure. For the purposes of this exclusion, a historic building shall be any of the following: 2.1. Listed or preliminarily determined to be eligible for listing in the National Register of Historic Places. 2.2. Determined by the Secretary of the US Department of Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined to qualify as a historic district. 2.3. Designated as historic under a state or local historic preservation program that is approved by the Department of Interior.

    [MP] SUMP. A tank or pit that receives sewage or waste, located below the normal grade of the gravity system and that must be emptied by mechanical means.

    [MP] SUMP PUMP. A pump installed to empty a sump. These pumps are used for removing storm water only. The pump is selected for the specific head and volume of the load and is usually operated by level controllers.

    [RB] SUNROOM. A one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structure’s exterior walls and roof.

    [MP] SUPPLY AIR. Air delivered to a conditioned space through ducts or plenums from the heat exchanger of a heating, cooling or ventilating system.

    [MP] SUPPORTS. Devices for supporting, hanging and securing pipes, fixtures and equipment.

    [MP] SWEEP. A drainage fitting designed to provide a change in direction of a drain pipe of less than the angle specified by the amount necessary to establish the desired slope of the line. Sweeps provide a longer turning radius than bends and a less turbulent flow pattern (see “Bend” and “Elbow”).

    [MP] TEMPERATURE- AND PRESSURE-RELIEF (T AND P) VALVE. A combination relief valve designed to function as both a temperature-relief and pressure-relief valve.

    [MP] TEMPERATURE-RELIEF VALVE. A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.

    TERMINALLY ILL, as termed for an individual, means the individual has a life expectancy of six months or less as stated in writing by his or her attending physician and surgeon.

  • CHBC § 8-3 High relevance — show source text

    This shall include historical buildings or properties on, or determined eligible for, national, state or local historical registers or inventories, such as the National Register of Historic Places, California Register of Historical Resources, State Historical Landmarks, State Points of Historical Interest, and city or county registers, inventories or surveys of historical or architecturally significant sites, places or landmarks.

    RECONSTRUCTION. The act or process of depicting, by means of new construction, the form, features and detailing of a nonsurviving site, landscape, building, property or object for the purpose of replicating its appearance at a specific period of time.

    REGULAR CODE. The adopted regulations that govern the design and construction or alteration of nonhistorical buildings and properties within the jurisdiction of the enforcing agency.

    REHABILITATION. The act or process of making possible a compatible use for qualified historical building or property through repair, alterations and additions while preserving those portions or features which convey its qualified historical, cultural or architectural values.

    RELOCATION. The act or process of moving any qualified historical building or property or a portion of a qualified historical building or property to a new site, or a different location on the same site.

    REPAIR. Renewal, reconstruction or renovation of any portion of an existing property, site or building for the purpose of its continued use.

    RESTORATION. The act or process of accurately depicting the form, features and character of a qualified building or property as it appeared at a particular period of time by the means of the removal of features from other periods in its history and reconstruction of missing features from the restoration period. The limited and sensitive upgrading of mechanical, electrical and plumbing systems and other code-required work to make properties functional is appropriate within a restoration project.

    STRUCTURE. That which is built or constructed, an edifice or a building of any kind, or any piece of work artificially built up or composed of parts joined together in some definite manner.

    TREATMENT. An act of work to carry out preservation, restoration, stabilization, rehabilitation or reconstruction.

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    8-3 USE AND OCCUPANCY

    SECTION 8-301 PURPOSE AND SCOPE

    8-301.1 Purpose. The purpose of the CHBC is to provide regulations for the determination of occupancy classifications and conditions of use for qualified historical buildings or properties.

    8-301.2 Scope. Every qualified historical building or property for which a permit or approval has been requested shall be classified prior to permit issuance according to its use or the character of its occupancy in accordance with the regular code and applicable provisions of this chapter.

    SECTION 8-302 GENERAL

    8-302.1 Existing use. The use or character of occupancy of a qualified historical building or property, or portion thereof, shall be permitted to continue in use regardless of any period of time in which it may have remained unoccupied or in other uses, provided such building or property otherwise conforms to all applicable requirements of the CHBC.

    8-302.2 Change in occupancy. The use or character of the occupancy of a qualified historical building or property may be changed from or returned to its historical use or character, provided the qualified historical building or property conforms to the requirements applicable to the new use or character of occupancy as set forth in the CHBC. Such change in occupancy shall not mandate conformance with new construction requirements as set forth in regular code.

  • CHBC § 0.10 High relevance — show source text

    Examples of structural composite lumber are:

    Laminated strand lumber (LSL). A composite of wood strand elements with wood fibers primarily oriented along the length of the member, where the least dimension of the wood strand elements is 0.10 inch (2.54 mm) or less and their average lengths are not less than 150 times the least dimension of the wood strand elements.

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    DEFINITIONS

    Laminated veneer lumber (LVL). A composite of wood veneer elements with wood fibers primarily oriented along the length of the member, where the veneer element thicknesses are 0.25 inch (6.4 mm) or less.

    Oriented strand lumber (OSL). A composite of wood strand elements with wood fibers primarily oriented along the length of the member, where the least dimension of the wood strand elements is 0.10 inch (2.54 mm) or less and their average lengths are not less than 75 times and less than 150 times the least dimension of the wood strand elements.

    Parallel strand lumber (PSL). A composite of wood strand elements with wood fibers primarily oriented along the length of the member, where the least dimension of the wood strand elements is 0.25 inch (6.4 mm) or less and their average lengths are not less than 300 times the least dimension of the wood strand elements.

    [RB] STRUCTURAL INSULATED PANEL (SIP). A structural sandwich panel that consists of a lightweight foam plastic core securely laminated between two thin, rigid wood structural panel facings.

    [RB] STRUCTURE. That which is built or constructed.

    [RB] SUBSOIL DRAIN. A drain that collects subsurface water or seepage water and conveys such water to a place of disposal.

    [RB] SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its beforedamaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

    [RB] SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, alteration, addition or other improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

    1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
    2. Any alteration of a historic structure provided that the alteration will not preclude the structure’s continued designation as a historic structure. For the purposes of this exclusion, a historic building shall be any of the following: 2.1. Listed or preliminarily determined to be eligible for listing in the National Register of Historic Places. 2.2. Determined by the Secretary of the US Department of Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined to qualify as a historic district. 2.3. Designated as historic under a state or local historic preservation program that is approved by the Department of Interior.
  • CHBC § 3.4. High relevance — show source text

    [BS] ROOF COATING. A fluid-applied adhered coating used for roof maintenance, roof repair or as a component of a roof covering system or roof assembly.

    [BS] ROOF RECOVER. The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.

    [BS] ROOF REPAIR. Reconstruction or renewal of any part of an existing roof for the purpose of correcting damage or restoring the predamage condition.

    [BS] ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.

    SPC SEISMIC SEPARATION. [OSHPD 1 & 1R] Means a building separation in accordance with the California Administrative Code, Chap- ter 6 Section 3.4.

    SUBSTANDARD BUILDING. [HCD 1, HCD 2] See Health and Safety Code Section 17920.3.

    [BG] STORM SHELTER. A building, structure or portions thereof, constructed in accordance with ICC 500, designated for use during hurricanes, tornadoes or other severe windstorms.

    [BS] SUBSTANTIAL DAMAGE. For the purpose of determining compliance with the flood provisions of this code, damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

    [BS] SUBSTANTIAL IMPROVEMENT. For the purpose of determining compliance with the flood provisions of this code, any repair, alteration, addition or improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure, before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either of the following:

    1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the code official and that is the minimum necessary to ensure safe living conditions.
    2. Any alteration of a historic structure, provided that the alteration will not preclude the structure’s continued designation as a historic structure.

    [BS] SUBSTANTIAL STRUCTURAL ALTERATION. An alteration in which the gravity load-carrying structural elements altered within a 5-year period support more than 30 percent of the total floor and roof area of the building or structure. The areas to be counted toward the 30 percent shall include mezzanines, penthouses, and in-filled courts and shafts tributary to the altered structural elements.

    [BS] SUBSTANTIAL STRUCTURAL DAMAGE. A condition where any of the following apply:

    1. The vertical elements of the lateral force-resisting system have suffered damage such that the lateral load-carrying capacity of any story in any horizontal direction has been reduced by more than 33 percent from its predamage condition.
    2. The capacity of any vertical component carrying gravity load, or any group of such components, that has a tributary area more than 30 percent of the total area of the structure’s floor(s) and roof(s) has been reduced more than 20 percent from its predamage condition, and the remaining capacity of such affected elements, with respect to all dead and live loads, is less than 75 percent of that required by the California Building Code for new buildings of similar structure, purpose and location.
  • CHBC § 1.8.3 High relevance — show source text

    SECTION 1.8.3—LOCAL ENFORCING AGENCY

    1.8.3.1 Duties and powers. The building department of every city, county, or city and county shall enforce all the provisions of law, this code, and the other rules and regulations promulgated by the Department of Housing and Community Development pertaining to the installation, erection, construction, reconstruction, movement, enlargement, conversion, alteration, repair, removal, demolition or

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    DIVISION I CALIFORNIA ADMINISTRATION

    arrangement of apartments, condominiums, hotels, motels, lodging houses and dwellings, including accessory buildings, facilities and uses thereto.

    The provisions regulating the erection and construction of dwellings and appurtenant structures shall not apply to existing structures as to which construction is commenced or approved prior to the effective date of these regulations. Requirements relating to use, main- tenance and occupancy shall apply to all dwellings and appurtenant structures approved for construction or constructed before or after the effective date of this code.

    For additional information regarding the use and occupancy of existing buildings and appurtenant structures, see California Code of Regulations, Title 25, Division 1, Chapter 1, Subchapter 1, commencing with Article 1, Section 1.

    For additional requirements regarding additions, alterations or repairs to existing buildings and appurtenant structures, see the Cali- fornia Existing Building Code.

    1.8.3.2 Laws, rules and regulations. Other than the building standards contained in this code, and notwithstanding other provisions of law, the statutory authority and location of the laws, rules and regulations to be enforced by local enforcing agencies are listed by stat- ute in Sections 1.8.3.2.1 through 1.8.3.2.5 below:

    1.8.3.2.1 State Housing Law. Refer to the State Housing Law, California Health and Safety Code, Division 13, Part 1.5, commencing with Section 17910 and California Code of Regulations, Title 25, Division 1, Chapter 1, Subchapter 1, commencing with Section 1, for the erec- tion, construction, reconstruction, movement, enlargement, conversion, alteration, repair, removal, demolition or arrangement of apartments, condominiums, hotels, motels, lodging houses and dwellings, including accessory buildings, facilities and uses thereto.

    1.8.3.2.2 Mobilehome Parks Act. Refer to the Mobilehome Parks Act, California Health and Safety Code, Division 13, Part 2.1, commencing with Section 18200 and California Code of Regulations, Title 25, Division 1, Chapter 2, commencing with Section 1000 for mobilehome park administrative and enforcement authority, permits, plans, fees, violations, inspections and penalties both within and outside mobilehome parks.

    Exception: Mobilehome parks where the Department of Housing and Community Development is the enforcing agency.

  • CHBC § 102.1 High relevance — show source text

    SECTION 102—APPLICABILITY

    [A] 102.1 Construction and design provisions. The construction and design provisions of this code shall apply to:

    1. Structures, facilities and conditions arising after the adoption of this code.
    2. Existing structures, facilities and conditions not legally in existence at the time of adoption of this code.
    3. Existing structures, facilities and conditions where required in Chapter 11.
    4. Existing structures, facilities and conditions that, in the opinion of the fire code official, constitute a distinct hazard to life or property.

    [A] 102.2 Administrative, operational and maintenance provisions. The administrative, operational and maintenance provisions of this code shall apply to:

    1. Conditions and operations arising after the adoption of this code.
    2. Existing conditions and operations.

    [A] 102.3 Change of use or occupancy. A change of occupancy shall not be made unless the use or occupancy is made to comply with the requirements of this code and the California Existing Building Code .

    Exception: Where approved by the fire code official, a change of occupancy shall be permitted without complying with the requirements of this code and the California Existing Building Code, provided that the new or proposed use or occupancy is less hazardous, based on life and fire risk, than the existing use or occupancy.

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    DIVISION II—SCOPE AND ADMINISTRATION

    [A] 102.4 Application of building code. The design and construction of new structures shall comply with the California Building Code, and any alterations, additions, changes in use or changes in structures required by this code, which are within the scope of the California Building Code, shall be made in accordance therewith.

    [A] 102.5 Application of residential code. Where structures are designed and constructed in accordance with the California Residen- tial Code, the provisions of this code shall apply as follows:

    1. Construction and design provisions of this code pertaining to the exterior of the structure shall apply including, but not limited to, premises identification, fire apparatus access and water supplies. Where interior or exterior systems or devices are installed, construction permits required by Section 105.6 shall apply.
    2. Administrative, operational and maintenance provisions of this code shall apply.

    [A] 102.6 Historic buildings. The provisions of this code relating to the construction, alteration, repair, enlargement, restoration, relocation or moving of buildings or structures shall not be mandatory for existing buildings or structures identified and classified by the state or local jurisdiction as historic buildings where such buildings or structures do not constitute a distinct hazard to life or property. Fire protection in designated historic buildings shall be provided with an approved fire protection plan as required in Section 1103.1.1.

    [A] 102.7 Referenced codes and standards. The codes and standards referenced in this code shall be those that are listed in Chapter 80, and such codes and standards shall be considered to be part of the requirements of this code to the prescribed extent of each such reference and as further regulated by Sections 102.7.1 and 102.7.2.

    [A] 102.7.1 Conflicts. Where conflicts occur between provisions of this code and referenced codes and standards, the provisions of this code shall apply.

  • CHBC § 1.10.1 High relevance — show source text

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    Chapter 3 Provisions for All Compliance Methods.

    Chapter 3 guides the use of the three compliance methods of the CEBC and provides requirements that apply globally. The globally applicable requirement include general requirements related to buildings materials and other applicable codes, storm shelters, structural loads, in-situ load tests, accessibility, smoke alarms, carbon monoxide detection and exterior wall coverings.

    Chapter 3A Provisions for All Compliance Methods.

    Chapter 3A controls the compliance options for alteration, repair, addition, evaluation and change of occupancy of existing structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).

    Chapter 4 Repairs.

    Chapter 4, a chapter independent of the three compliance methods, governs the repair 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.

    Chapter 4A Repairs.

    Chapter 4A governs the repair of existing buildings regulated by the Department of Health Care Access and Information/Office of State- wide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).

    Chapter 5 Prescriptive Compliance Method.

    Chapter 5 provides one of the three main options of compliance available in the CEBC for buildings and structures undergoing alteration, addition or change of occupancy. The base requirements are more administrative in nature. The structural triggers for upgrades are consistent with the Work Area Method.

    Chapter 5A Prescriptive Compliance Method.

    Chapter 5A provides details for the prescriptive compliance method for alteration, addition and change of occupancy of existing build- ings and structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).

    Chapter 6 Classification of Work.

    Chapter 6 provides an overview of the Work Area Method and defines the different classifications of work including alterations, change of occupancy, additions and historic buildings. Detailed requirements for all of these are given in subsequent Chapters 7 through 11.

    Chapter 7 Alterations—Level 1.

    Chapter 7 provides the technical requirements for those existing buildings that undergo Level 1 alterations as described in Section 602, which includes replacement or covering of existing materials, elements, equipment or fixtures using new materials for the same purpose. This chapter is distinguished from Chapters 8 and 9 by only involving replacement of building components with new components with no reconfiguration of space.

    Chapter 8 Alterations—Level 2.

    A Level 2 alteration is an alteration involving space reconfiguration that could be up to and including 50 percent of the area of the building or addition of a new building system. Level 2 alterations also include the extension or addition of any system or equipment. The purpose of Chapter 8 is to provide detailed requirements and provisions to identify the required improvements in the existing building elements, means of egress, fire protection, structural systems, energy efficiency, and other building systems include electrical, mechanical and plumbing when a building is being altered.

    Chapter 9 Alterations—Level 3.

  • CHBC § 8-1002.1 High relevance — show source text

    8-1002.1 The CHBC shall apply to all sites and districts and their features associated with qualified historical buildings or qualified historical districts as outlined in 8-1001.2 Scope.

    8-1002.2 Where the application of regular code may impact the associated features of qualified historical properties beyond their footprints, by work performed secondarily, those impacts shall also be covered by the CHBC.

    8-1002.3 This chapter shall be applied for all issues regarding code compliance or other standard or regulation as they affect the purpose of this chapter.

    8-1002.4 The application of any code or building standard shall not unduly restrict the use of a qualified historical building or property that is otherwise permitted pursuant to Chapter 8-3 and the intent of the State Historical Building Code, Section 18956.

    SECTION 8-1003 SITE RELATIONS

    The relationship between a building or property and its site, or the associated features of a district (including qualified historical landscape), site, objects and their features are critical components that may be one of the criteria for these buildings and properties to be qualified under the CHBC. The CHBC recognizes the importance of these relationships. This chapter shall be used to provide context sensitive solutions for treatment of qualified historical buildings, properties, district or their associated historical features, or when work to be performed secondarily impacts the associated historical features of a qualified historical building or property.

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    APPENDIX A Col2 Col3 Col4
    CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY
    Title II
    Public Entities
    Title III
    Private Entities
    Title III
    Barrier Removal
    SECTION 8-601 PURPOSE, INTENT, SCOPE
    **8-601.1 Purpose.**The purpose of the CHBC is to provide alternative regulations to facilitate
    access and use by persons with disabilities to and throughout facilities designated as quali-
    fied historical buildings or properties. These regulations require enforcing agencies to
    accept alternatives to regular code when dealing with qualified historical buildings or
    properties.
    **8-601.2 Intent.**The intent of this chapter is to preserve the integrity of qualified historical
    buildings and properties while providing access to and use by persons with disabilities.
    **8-601.3 Scope.**The CHBC shall apply to every qualified historical building or property that
    is required to provide access to persons with disabilities.
    1.Provisions of this chapter do not apply to new construction or reconstruction/replicas of
    historical buildings.
    2. Where provisions of this chapter apply to alteration of qualified historical buildings or
    properties, alteration is defined in_ California Building Code_ (CBC), Chapter 2.
    **8-601.4 General application.
  • CHBC § 8-101.1 High relevance — show source text

    8-101.1 Title. These regulations shall be known as the California Historical Building Code and will be referred to herein as “the CHBC.”

    8-101.2 Purpose. The purpose of the CHBC is to provide regulations for the preservation, restoration, rehabilitation, relocation or reconstruction of buildings or properties designated as qualified historical buildings or properties (as defined in Chapter 8-2). The CHBC is intended to provide solutions for the preservation of qualified historical buildings or properties, to promote sustainability, to provide access for persons with disabilities, to provide a cost-effective approach to preservation, and to provide for the reasonable safety of the occupants or users. The CHBC requires enforcing agencies to accept solutions that are reasonably equivalent to the regular code (as defined in Chapter 8-2) when dealing with qualified historical buildings or properties.

    8-101.3 Intent. The intent of the CHBC is to facilitate the preservation and continuing use of qualified historical buildings or properties while providing reasonable safety for the building occupants and access for persons with disabilities.

    SECTION 8-102 APPLICATION

    8-102.1 Application. The CHBC is applicable to all issues regarding code compliance for qualified historical buildings or properties. The CHBC may be used in conjunction with the regular code to provide solutions to facilitate the preservation of qualified historical buildings or properties. The CHBC shall be used by any agency with jurisdiction and whenever compliance with the code is required for qualified historical buildings or properties.

    1. State or local enforcing agency. The state or local enforcing agency shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, reconstruction, rehabilitation, relocation or continued use of a qualified historical building or property when so elected by the private property owner.
    2. State agencies. All state agencies shall apply the provisions of the CHBC in permitting repairs, alterations and additions necessary for the preservation, restoration, rehabilitation, safety, relocation, reconstruction or continued use of qualified historical buildings or properties.

    8-102.1.1 Additions, alterations and repairs. It is the intent of the CHBC to allow nonhistorical expansion or addition to a qualified historical building or property, provided nonhistorical additions shall conform to the requirements of the regular code (as defined in Chapter 8-2).

    8-102.1.2 Relocation. Relocated qualified historical buildings or properties shall be sited to comply with the regular code or with the solutions listed in the CHBC. Nonhistorical new construction related to relocation shall comply with the regular code. Reconstruction and restoration related to relocation is permitted to comply with the provisions in the CHBC.

    8-102.1.3 Change of occupancy. For change of use or occupancy, see Chapter 8-3, Use and Occupancy.

    8-102.1.4 Continued use. Qualified historical buildings or properties may have their existing use or occupancy continued if such use or occupancy conformed to the code or to the standards of construction in effect at the time of construction, and such use or occupancy does not constitute a distinct hazard to life safety as defined in the CHBC.

    8-102.1.5 Unsafe buildings or properties. When a qualified historical building or property is determined to be unsafe as defined in the regular code, the requirements of the CHBC are applicable to the work necessary to correct the unsafe conditions. Work to remediate the buildings or properties need only address the correction of the unsafe conditions, and it shall not be required to bring the entire qualified historical building or property into compliance with regular code.

  • CHBC § 8-503 Medium relevance — show source text

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    MEANS OF EGRESS

    SECTION 8-503 ESCAPE OR RESCUE WINDOWS AND DOORS

    Basements in dwelling units and every sleeping room below the fourth floor shall have at least one openable window or door approved for emergency escape which shall open directly into a public street, public way, yard or exit court. Escape or rescue windows or doors shall have a minimum clear area of 3.3 square feet (0.31 m [2] ) and a minimum width or height dimension of 18 inches (457 mm) and be operable from the inside to provide a full, clear opening without the use of special tools.

    SECTION 8-504 RAILINGS AND GUARDRAILS

    The height of railings and guard railings and the spacing of balusters may continue in their historical height and spacing unless a distinct hazard has been identified or created by a change in use or occupancy.

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    8-6 ACCESSIBILITY

    SECTION 8-601 PURPOSE, INTENT AND SCOPE

    8-601.1 Purpose. The purpose of the CHBC is to provide alternative regulations to facilitate access and use by persons with disabilities to and throughout facilities designated as qualified historical buildings or properties. These regulations require enforcing agencies to accept alternatives to regular code when dealing with qualified historical buildings or properties.

    8-601.2 Intent. The intent of this chapter is to preserve the integrity of qualified historical buildings and properties while providing access to and use by persons with disabilities.

    8-601.3 Scope. The CHBC shall apply to every qualified historical building or property that is required to provide access to persons with disabilities.

    1. Provisions of this chapter do not apply to new construction or reconstruction/replicas of historical buildings.
    2. Where provisions of this chapter apply to alteration of qualified historical buildings or properties, alteration is defined in California Building Code (CBC), Chapter 2.

    8-601.4 General application. The provisions in the CHBC apply to local, state and federal governments (Title II entities); alteration of commercial facilities and places of public accommodation (Title III entities); and barrier removal in commercial facilities and places of public accommodation (Title III entities). Except as noted in this chapter.

    SECTION 8-602 BASIC PROVISIONS

    8-602.1 Regular code. The regular code for access for people with disabilities (Title 24, Part 2, Vol. 1, Chapter 11B) shall be applied to qualified historical buildings or properties unless strict compliance with the regular code will threaten or destroy the historical significance or character-defining features of the building or property.

    8-602.2 Alternative provisions. If the historical significance or character-defining features are threatened, alternative provisions for access may be applied pursuant to this chapter, provided the following conditions are met:

    1. These provisions shall be applied only on an item-by-item or a case-by-case basis.
    2. Documentation is provided, including meeting minutes or letters, stating the reasons for the application of the alternative provisions. Such documentation shall be retained in the permanent file of the enforcing agency.

    SECTION 8-603 ALTERNATIVES

Frequently asked questions

Do I need to upgrade historic windows when I repair my house?

Not necessarily. § 8-303.7 allows replacement/retention of original materials and methods unless the work creates or continues a life safety hazard. If a window is a required egress opening (basement or sleeping room), any replacement must meet § 8-503 minimums.

Are there limits to how much I can alter a historic residence?

CHBC does not place a numeric limit on the amount of alteration/repair so long as there is no nonhistorical increase in floor area, volume or size and no life safety hazard is created or continued. See § 8-303.7.

Can an existing fire escape count as an exit?

Yes — existing previously approved fire escapes and ladders may be accepted as one required means of egress if they extend to the ground, are easily negotiated, signed and in good working order; access opening and sill height minimums apply (see § 8-502.5).

What exactly must an escape window provide?

Per § 8-503: at least one openable window or door opening directly to a public street/way/yard/exit court for basements and sleeping rooms below the fourth floor; minimum clear area 3.3 sq ft and minimum width or height 18 in; operable from inside without special tools.

If I add a nonhistorical addition, do I still use the CHBC?

Nonhistorical additions must conform to the regular code; the CHBC specifically allows nonhistorical expansion only when those additions comply with the regular code. See § 8-102.1.1.

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