CHBC · California Historical Building Code

How are exterior walls and openings protected using sprinkler systems?

Under the CHBC you may meet exterior wall and opening fire‑resistance requirements by installing an automatic sprinkler system designed for exposure protection — with at least one sprinkler over each protected opening, additional heads along combustible walls under the roofline, and a water connection as allowed — while following the NFPA standard required by the CHBC and the enforcing agency.

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

The CHBC allows existing exterior wall fire‑resistance and required opening protection to be satisfied by an automatic sprinkler system designed for exposure protection rather than by reconstructing fire‑resistive walls. The sprinkler installation may be located on the exterior, must include at least one sprinkler located over each opening required to be protected, and must include additional sprinklers distributed along combustible walls under roof lines when those walls do not meet the regular code exposure requirements. These provisions are stated in § 8-402.1 and the automatic sprinkler standards used are specified by § 8-410.2.

The single most important rule: you may meet exterior wall and opening fire‑resistance requirements by installing an exterior sprinkler system that provides exposure protection, placing at least one sprinkler over every opening that needs protection, and distributing extra heads along combustible exterior walls under the roofline.

Requirements in detail

Basic substitution allowed

  • The fire‑resistance requirement for existing exterior walls and opening protectives may be satisfied by an automatic sprinkler system designed for exposure protection rather than rebuilding walls to a fire‑resistive rating. § 8-402.1.

Where sprinklers are placed and how they are connected

  • Sprinklers may be installed on the exterior of the building. § 8-402.1.
  • The system must include at least one sprinkler over each opening required to be protected. § 8-402.1.
  • Additional sprinklers must be distributed along combustible walls under the roof lines where walls do not meet the fire‑resistive requirement due to property‑line relationships. § 8-402.1.
  • The sprinkler system may be connected to the domestic water supply on the supply‑main side of the building shut‑off valve; a shut‑off valve for the sprinkler system is permitted only if locked in the open position. § 8-402.1.

Which sprinkler standard to use

  • The CHBC defers to NFPA standards by building type/height in § 8-410.2. For exterior wall/opening protection the CHBC refers you back to the chapter requirements (see § 8-410.2(5)). In practice the CHBC identifies NFPA 13, NFPA 13R and NFPA 13D as the adopted standards by circumstance; use the higher standard where required by the CHBC or the enforcing agency. § 8-410.2.
  • NOTE: The CHBC also contains an Exception that requires an upgrade of the NFPA standard (for repeated use of a lower standard) in certain circumstances — review § 8-410.2 for that limitation.

Non‑substitution limits

  • An automatic sprinkler system may satisfy exterior wall/opening fire‑resistance requirements, but sprinklers cannot be used to reduce the required number of means of egress. See § 8-410.3.

Decision‑relevant dimensions/values (summary table)

Decision item Required value / action Code Reference
Minimum heads over openings At least one sprinkler located over each opening required to be protected § 8-402.1
Additional protection along walls Additional sprinklers distributed along combustible walls under the roof lines when walls don't meet fire‑resistive requirements § 8-402.1
Exterior installation allowed Sprinklers may be installed on the exterior § 8-402.1
Water supply connection May connect to domestic water supply on the supply‑main side of building shut‑off valve § 8-402.1
Shut‑off valve Permitted if locked in an open position § 8-402.1
Which NFPA standard Use NFPA 13 / 13R / 13D as applicable; exterior wall/opening protection “as required by this chapter” (see § 8-410.2) § 8-410.2
No substitution for exits Sprinklers do not reduce required number of exits § 8-410.3

If you need to show the enforcing agency compliance, reference the CHBC sections above while providing your sprinkler design documentation and NFPA standard compliance sheets.

Exceptions & special cases

  • A shut‑off valve for the sprinkler system is allowed, but it must be locked in the open position to comply with § 8-402.1.
  • If a building is made compliant by an automatic sprinkler system throughout, certain one‑hour construction upgrades or opening protective upgrades may be waived under § 8-402.2 and related CHBC provisions.
  • The CHBC permits historical glazing and unrated solid wood doors in interior one‑hour walls when the affected area is provided with an automatic sprinkler system (see § 8-402.3).
  • The CHBC’s reference to NFPA standards (in § 8-410.2) means the enforcing agency may require NFPA 13 rather than 13R/13D depending on building height, occupancy and how the sprinkler approach is used for compliance.

Note: the CHBC text requires distribution of sprinklers (one over each opening and additional along combustible walls), but it does not by itself set exact sprinkler spacing, K‑factor, or hydraulic design points — those detailed design parameters are provided by the referenced NFPA standard and by the enforcing agency’s plan review. The CHBC specifies the performance/placement approach rather than detailed hydraulic spacing rules. § 8-402.1 and § 8-410.2.

Common mistakes

  • Assuming any interior sprinkler system layout meets the CHBC substitution — the CHBC specifically allows exterior sprinkler installation and requires heads over openings and distributed along combustible walls; missing those placements is noncompliant. § 8-402.1.
  • Installing a shut‑off valve that is not locked open or that isolates the sprinkler from the supply‑main side of the building shut‑off valve without approval — the CHBC allows the valve only if locked in the open position. § 8-402.1.
  • Relying on a lower NFPA standard (e.g., NFPA 13D) repeatedly without recognizing the CHBC Exception that may force an upgrade to NFPA 13R or NFPA 13 after repeated use — see § 8-410.2.
  • Using sprinkler protection to justify fewer exits, or to alter means of egress requirements — CHBC expressly prohibits substituting sprinklers for required exits. § 8-410.3.

Worked example — applying the rule with numbers

Scenario: A 2‑story qualified historical building has a combustible exterior wall under the eave facing a narrow lot line and that wall contains 4 existing windows which, under the regular code, would require opening protection.

How to apply CHBC rules:

  1. The owner elects to use sprinkler protection to meet the exterior wall/opening requirement under § 8-402.1.
  2. Provide at least one sprinkler head directly over each of the 4 windows (so minimum 4 exterior sprinkler heads covering the openings). § 8-402.1.
  3. Because the wall is combustible and under the roof line, add additional sprinklers distributed along the combustible wall under the roof line. The CHBC requires distribution but does not state a precise spacing number — the designer must follow the applicable NFPA standard (selected per § 8-410.2) for hydraulic design and demonstrate to the enforcing agency that the wall will receive exposure protection. § 8-402.1; § 8-410.2.
  4. Connect the sprinkler system to the domestic water supply on the supply‑main side of the building shut‑off valve, and, if a sprinkler shut‑off is installed, ensure it is locked in the open position per § 8-402.1.
  5. Submit hydraulic calculations and NFPA‑compliant shop drawings (NFPA 13R or NFPA 13 as required by building characteristics and § 8-410.2) to the enforcing agency for approval. § 8-410.2.

Practical note: the CHBC tells you what to achieve (sprinkler exposure protection, heads over openings, distribution along combustible walls, supply connection and locked valve). For exact hydraulic spacing, head selection and density, use the NFPA standard applicable to your building as referenced in § 8-410.2 and get enforcing‑agency concurrence.

Related provisions

  • § 8-402.2 — One‑hour construction may be waived where an automatic sprinkler system is provided throughout.
  • § 8-402.3 — Historical glazing and solid wood unrated doors in one‑hour interior walls may be approved when the area is provided with an automatic sprinkler system.
  • § 8-410.2 — Specifies the NFPA sprinkler standards adopted by the State Fire Marshal and notes exterior wall/opening protection is addressed by this chapter.
  • § 8-410.3 — Automatic sprinkler systems shall not substitute for required exits.
  • § 8-302.3 — Occupancy separations may be reduced when the building is provided with an automatic sprinkler system throughout (related life‑safety tradeoffs).

(If you need plan‑check language or a template compliance narrative for the enforcing agency, I can draft one keyed to these sections and to your building specifics.)

Code references

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

  • CHBC § 8-402 High relevance — show source text

    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

    New non-historical interior wall and ceiling finishes shall conform to the provisions of the regular code. Existing non-conforming materials used in interior walls and finishes may be surfaced with an approved fire-retardant to increase the rating of the natural finish to within reasonable proximity of the required rating. For wood lath and plaster walls, see Section 8-404.

    Exception: When an automatic sprinkler system is provided throughout the building, existing finishes shall be approved.

    SECTION 8-404 — WOOD LATH AND PLASTER

    Wood lath and plaster walls may be considered in accordance with codes, standards and listings published prior to 1943 whereby a wood stud wall assembly with gypsum or lime plaster on hand split or sawn wooden lath obtains a one-half-hour fire-resistive rating. This rating may be increased for interior walls to as much as one hour by filling the wall with mineral fiber or glass fiber.

    SECTION 8-405 — OCCUPANCY SEPARATION

    See Chapter 8-3.

    SECTION 8-406 — MAXIMUM FLOOR AREA

    See Chapter 8-3.

    SECTION 8-407 — VERTICAL SHAFTS

    Vertical shafts need not be enclosed when such shafts are blocked at every floor level by the installation of not less than 2 full inches (51 mm) of solid wood or equivalent construction to prevent the initial passage of smoke and flame. Automatic sprinkler systems or other solutions may be considered on a case-by-case basis, in lieu of enclosure of vertical shafts and stairwells.

    SECTION 8-408 — ROOF COVERING

    Existing or original roofing materials may be repaired or reconstructed subject to the following requirements:

    1. The original or historical roofing system shall be detailed or modified as necessary in order to be capable of providing shelter while preserving the historical materials and appearance of the roof.
  • CHBC § 3104.5.1.1 High relevance — show source text

    3104.5.1.1 Exterior walls. Exterior walls of buildings connected to pedestrian walkways shall be 2-hour fire-resistance rated. This protection shall extend not less than 10 feet (3048 mm) in every direction surrounding the perimeter of the pedestrian walkway.

    3104.5.1.2 Openings in exterior walls of connected buildings. Openings in exterior walls required to be fire-resistance rated in accordance with Section 3104.5.1.1 shall be equipped with opening protectives providing a not less than [3] / 4 -hour fire protection rating in accordance with Section 716.

    3104.5.1.3 Supporting construction. The fire barrier shall be supported by construction as required by Section 707.5.1.

    3104.5.2 Alternative separation. The wall separating the pedestrian walkway and the building shall comply with Section 3104.5.2.1 or 3104.5.2.2 where:

    1. The distance between the connected buildings is more than 10 feet (3048 mm).
    2. The pedestrian walkway and connected buildings are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, and the roof of the walkway is not more than 55 feet (16 764 mm) above grade connecting to the fifth, or lower, story above grade plane, of each building.

    Exception: Open parking garages need not be equipped with an automatic sprinkler system.

    3104.5.2.1 Passage of smoke. The wall shall be capable of resisting the passage of smoke.

    3104.5.2.2 Glass. The wall shall be constructed of a tempered, wired or laminated glass and doors separating the interior of the building from the pedestrian walkway. The glass shall be protected by an automatic sprinkler system in accordance with Section 903.3.1.1 that, when actuated, shall completely wet the entire surface of interior sides of the wall or glass. Obstructions shall not be installed between the sprinkler heads and the wall or glass. The glass shall be in a gasketed frame and installed in such a manner that the framing system will deflect without breaking (loading) the glass before the sprinkler operates.

    3104.5.3 Open sides on walkway. Where the distance between the connected buildings is more than 10 feet (3048 mm), the walls at the intersection of the pedestrian walkway and each building need not be fire-resistance rated provided that both sidewalls of the pedestrian walkway are not less than 50 percent open with the open area uniformly distributed to prevent the

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    accumulation of smoke and toxic gases. The roof of the walkway shall be located not more than 40 feet (12 160 mm) above grade plane, and the walkway shall only be permitted to connect to the third or lower story of each building.

    Exception: Where the pedestrian walkway is protected with an automatic sprinkler system in accordance with Section 903.3.1.1, the roof of the walkway shall be located not more than 55 feet (16 764 mm) above grade plane and the walkway shall only be permitted to connect to the fifth or lower story of each building.

  • 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 § 903.2.11.1 High relevance — show source text

    903.2.11.1 Stories without openings. An automatic sprinkler system shall be installed throughout all stories, including basements, of all buildings where the floor area exceeds 1,500 square feet (139 m [2] ) and where the story does not comply with the following criteria for exterior wall openings:

    1. Openings below grade that lead directly to ground level by an exterior stairway complying with Section 1011 or an outside ramp complying with Section 1012. Openings shall be located in each 50 linear feet (15 240 mm), or fraction thereof, of exterior wall in the story on not fewer than one side. The required openings shall be distributed such that the lineal distance between adjacent openings does not exceed 50 feet (15 240 mm).
    2. Openings entirely above the adjoining ground level totaling not less than 20 square feet (1.86 m [2] ) in each 50 linear feet (15 240 mm), or fraction thereof, of exterior wall in the story on not fewer than one side. The required openings shall be distributed such that the lineal distance between adjacent openings does not exceed 50 feet (15 240 mm). The height of the bottom of the clear opening shall not exceed 44 inches (1118 mm) measured from the floor.

    903.2.11.1.1 Opening dimensions and access. Openings shall have a minimum dimension of not less than 30 inches (762 mm). Access to such openings shall be provided for the fire department from the exterior and shall not be obstructed in a manner such that firefighting or rescue cannot be accomplished from the exterior.

    903.2.11.1.2 Openings on one side only. Where openings in a story are provided on only one side and the opposite wall of such story is more than 75 feet (22 860 mm) from such openings, the story shall be equipped throughout with an approved automatic sprinkler system, or openings shall be provided on not fewer than two sides of the story.

    903.2.11.1.3 Basements. Where any portion of a basement is located more than 75 feet (22 860 mm) from openings required by Section 903.2.11.1, or where walls, partitions or other obstructions are installed that restrict the application of water from hose streams, the basement shall be equipped throughout with an approved automatic sprinkler system.

    903.2.11.2 Rubbish and linen chutes. An automatic sprinkler system shall be installed at the top of rubbish and linen chutes and in their terminal rooms. Chutes shall have additional sprinkler heads installed at alternate floors and at the lowest intake. Where a rubbish chute extends through a building more than one floor below the lowest intake, the extension shall have sprinklers installed that are recessed from the drop area of the chute and protected from freezing in accordance with Section

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    903.3.1.1. Such sprinklers shall be installed at alternate floors, beginning with the second level below the last intake and ending with the floor above the discharge. Access to sprinklers in chutes shall be provided for servicing.

  • CHBC § 705.9.2 High relevance — show source text
    1. Buildings whose exterior bearing walls, exterior nonbearing walls and exterior primary structural frame are not required to be fire-resistance rated shall be permitted to have unlimited unprotected openings.

    705.9.2 Protected openings. Where openings are required to be protected, opening protectives shall comply with Section 716.

    Exception: Opening protectives are not required where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 and the exterior openings are protected by a water curtain using automatic sprinklers approved for that use.

    705.9.3 Unprotected openings. Where unprotected openings are permitted, windows and doors shall be constructed of any approved materials. Glazing shall conform to the requirements of Chapters 24 and 26.

    705.9.4 Mixed openings. Where both unprotected and protected openings are located in the exterior wall in any story of a building, the total area of openings shall be determined in accordance with the following: Equation 7-2 ( A p / a p ) + ( A u / a u ) ≤ 1 A p = Actual area of protected openings, or the equivalent area of protected openings, A e (see Section 705.8). a p = Allowable area of protected openings. A u = Actual area of unprotected openings.

    a u = Allowable area of unprotected openings.

    705.9.5 Vertical separation of openings. Openings in exterior walls in adjacent stories shall be separated vertically to protect against fire spread on the exterior of the buildings where the openings are within 5 feet (1524 mm) of each other horizontally and the opening in the lower story is not a protected opening with a fire protection rating of not less than [3] / 4 hour. Such openings shall be separated vertically not less than 3 feet (914 mm) by spandrel girders, exterior walls or other similar assemblies that have a fireresistance rating of not less than 1 hour, rated for exposure to fire from both sides, or by flame barriers that extend horizontally not less than 30 inches (762 mm) beyond the exterior wall. Flame barriers shall have a fire-resistance rating of not less than 1 hour. The unexposed surface temperature limitations specified in ASTM E119 or UL 263 shall not apply to the flame barriers unless otherwise required by the provisions of this code.

    Exceptions:

    1. This section shall not apply to buildings that are three stories or less above grade plane.
    2. This section shall not apply to buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.

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    FIRE AND SMOKE PROTECTION FEATURES

    1. Open parking garages. 705.9.6 Vertical exposure. For buildings on the same lot, opening protectives having a fire protection rating of not less than [3] / 4 hour shall be provided in every opening that is less than 15 feet (4572 mm) vertically above the roof of an adjacent building or structure based on assuming an imaginary line between them. The opening protectives are required where the fire separation distances from the imaginary line to each building or structure are less than 15 feet (4572 mm).
  • CHBC § 706.6.1. High relevance — show source text

    Values indicated are the percentage of the area of the exterior wall, per_story_.
    b. For the requirements for fire walls of buildings with differing heights, see Section 706.6.1.
    c. For openings in a fire wall for buildings on the same_lot_, see Section 706.8.
    d. The maximum percentage of unprotected and protected openings shall be 25 percent for Group R-3 occupancies.
    e. Unprotected openings shall not be permitted for openings with a fire separation distance of less than 15 feet for Group H-2 and H-3 occupancies.
    f. The area of unprotected and protected openings shall not be limited for Group R-3 occupancies, with a fire separation distance of 5 feet or greater.
    g. The area of openings in an open parking garage in accordance with Section 406.5 with a fire separation distance of 10 feet or greater shall not be limited.
    h. Includes buildings accessory to Group R-3.
    i. Not applicable to Group H-1, H-2 and H-3 occupancies.
    j. The area of openings in a building containing only a Group U occupancy private garage or carport with a fire separation distance of 5 feet or greater shall not be limited.
    k. For openings between S-2 parking garage and Group R-2 building, see Section 705.3, Exception 2.|

    705.9.1 Allowable area of openings. The maximum area of unprotected and protected openings permitted in an exterior wall in any story of a building shall not exceed the percentages specified in Table 705.9 based on the fire separation distance of each individual story.

    Exceptions:

    1. In other than Group H occupancies, unlimited unprotected openings are permitted in the first story above grade plane where the wall faces one of the following: 1.1. A street and has a fire separation distance of more than 15 feet (4572 mm). 1.2. An unoccupied space. The unoccupied space shall be on the same lot or dedicated for public use, shall be not less than 30 feet (9144 mm) in width and shall have access from a street by a posted fire lane in accordance with the California Fire Code.

    2. Buildings whose exterior bearing walls, exterior nonbearing walls and exterior primary structural frame are not required to be fire-resistance rated shall be permitted to have unlimited unprotected openings.

    705.9.2 Protected openings. Where openings are required to be protected, opening protectives shall comply with Section 716.

    Exception: Opening protectives are not required where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 and the exterior openings are protected by a water curtain using automatic sprinklers approved for that use.

    705.9.3 Unprotected openings. Where unprotected openings are permitted, windows and doors shall be constructed of any approved materials. Glazing shall conform to the requirements of Chapters 24 and 26.

    705.9.4 Mixed openings. Where both unprotected and protected openings are located in the exterior wall in any story of a building, the total area of openings shall be determined in accordance with the following: Equation 7-2 ( A p / a p ) + ( A u / a u ) ≤ 1 A p = Actual area of protected openings, or the equivalent area of protected openings, A e (see Section 705.8). a p = Allowable area of protected openings. A u = Actual area of unprotected openings.

  • CHBC § 1011.7.1 High relevance — show source text

    1011.7.1 Exterior wall rating for change of occupancy classification to a higher-hazard category. Where a change of occupancy classification is made to a higher hazard category as shown in Table 1011.7, exterior walls shall have fire-resistance, exterior opening areas and opening protectives as required by the California Building Code .

    Exception: A 2-hour fire-resistance rating shall be allowed where the building does not exceed three stories in height and is classified as one of the following groups: A-2 and A-3 with an occupant load of less than 300, B, F, M or S.

    1011.7.2 Exterior wall rating for change of occupancy classification to an equal or lesser-hazard category. Where a change of occupancy classification is made to an equal or lesser-hazard category as shown in Table 1011.7, existing exterior walls, including openings, shall be accepted.

    1011.7.3 Opening protectives. Openings in exterior walls shall be protected as required by the California Building Code . Where openings in the exterior walls are required to be protected because of their distance from the lot line, the sum of the area of such openings shall not exceed 50 percent of the total area of the wall in each story.

    Exceptions:

    1. Where the California Building Code permits openings in excess of 50 percent.

    2. Protected openings shall not be required in buildings of Group R occupancy that do not exceed three stories in height and that are located not less than 3 feet (914 mm) from the lot line.

    3. Exterior opening protectives are not required where an automatic sprinkler system has been installed throughout.

    4. Exterior opening protectives are not required where the change of occupancy group is to an equal or lower hazard classification in accordance with Table 1011.7.

    1011.8 Enclosure of vertical shafts. Enclosure of vertical shafts shall be in accordance with Sections 1011.8.1 through 1011.8.4.

    1011.8.1 Minimum requirements. Vertical shafts shall be designed to meet the California Building Code requirements for atriums or the requirements of this section.

    1011.8.2 Stairways. Where a change of occupancy classification is made to a higher-hazard category as shown in Table 1011.5, interior stairways shall be enclosed as required by the California Building Code .

    Exceptions:

    1. In other than Group I occupancies, an enclosure shall not be required for openings serving only one adjacent floor and that are not connected with corridors or stairways serving other floors.
    2. Unenclosed existing stairways need not be enclosed in a continuous vertical shaft if each story is separated from other stories by 1-hour fire-resistance-rated construction and all exit corridors are sprinklered in accordance with the California Building Code . The openings between the corridor and the tenant space shall have not fewer than one sprinkler above the openings on the tenant side.
    3. Existing penetrations of stairway enclosures shall be accepted if they are protected in accordance with the California Building Code .

    1011.8.3 Other vertical shafts. Interior vertical shafts other than stairways, including but not limited to elevator hoistways and service and utility shafts, shall be enclosed as required by the California Building Code where there is a change of use to a higherhazard category as specified in Table 1011.5.

  • CHBC § 903.3.1.1. High relevance — show source text

    8 mm.
    UP, NS = Unprotected openings in buildings not equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    UP, S = Unprotected openings in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    P = Openings protected with an opening protective assembly in accordance with Section 705.9.2.
    a. Values indicated are the percentage of the area of the exterior wall, per_story_.
    b. For the requirements for fire walls of buildings with differing heights, see Section 706.6.1.
    c. For openings in a fire wall for buildings on the same_lot_, see Section 706.8.
    d. The maximum percentage of unprotected and protected openings shall be 25 percent for Group R-3 occupancies.
    e. Unprotected openings shall not be permitted for openings with a fire separation distance of less than 15 feet for Group H-2 and H-3 occupancies.
    f. The area of unprotected and protected openings shall not be limited for Group R-3 occupancies, with a fire separation distance of 5 feet or greater.
    g. The area of openings in an open parking garage in accordance with Section 406.5 with a fire separation distance of 10 feet or greater shall not be limited.
    h. Includes buildings accessory to Group R-3.
    i. Not applicable to Group H-1, H-2 and H-3 occupancies.
    j. The area of openings in a building containing only a Group U occupancy private garage or carport with a fire separation distance of 5 feet or greater shall not be limited.
    k. For openings between S-2 parking garage and Group R-2 building, see Section 705.3, Exception 2.|For SI: 1 foot = 304.8 mm.
    UP, NS = Unprotected openings in buildings not equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    UP, S = Unprotected openings in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    P = Openings protected with an opening protective assembly in accordance with Section 705.9.2.
    a. Values indicated are the percentage of the area of the exterior wall, per_story_.
    b. For the requirements for fire walls of buildings with differing heights, see Section 706.6.1.
    c. For openings in a fire wall for buildings on the same_lot_, see Section 706.8.
    d. The maximum percentage of unprotected and protected openings shall be 25 percent for Group R-3 occupancies.
    e. Unprotected openings shall not be permitted for openings with a fire separation distance of less than 15 feet for Group H-2 and H-3 occupancies.
    f. The area of unprotected and protected openings shall not be limited for Group R-3 occupancies, with a fire separation distance of 5 feet or greater.
    g. The area of openings in an open parking garage in accordance with Section 406.5 with a fire separation distance of 10 feet or greater shall not be limited.
    h. Includes buildings accessory to Group R-3.
    i. Not applicable to Group H-1, H-2 and H-3 occupancies.
    j. The area of openings in a building containing only a Group U occupancy private garage or carport with a fire separation distance of 5 feet or greater shall not be limited.
    k.

  • CHBC § 1023.7 High relevance — show source text

    In each case, openings into the fire-resistance-rated construction shall be limited to those needed for maintenance and operation and shall be protected by opening protectives in accordance with Section 716 of the California Building Code for shaft enclosures.

    The interior exit stairway and ramp ventilation systems shall be independent of other building ventilation systems.

    [BE] 1023.7 Interior exit stairway and ramp exterior walls. Exterior walls of the interior exit stairway or ramp shall comply with the requirements of Section 705 of the California Building Code for exterior walls. Where nonrated walls or unprotected openings enclose the exterior of the stairway or ramps and the walls or openings are exposed by other parts of the building at an angle of less than 180 degrees (3.14 rad), building construction within 10 feet (3048 mm) of the exterior walls of the interior exit stairway or ramp shall comply with Sections 1023.7.1 and 1023.7.2.

    2025 CALIFORNIA FIRE CODE 10-47

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    MEANS OF EGRESS

    [BE] 1023.7.1 Building exterior walls. Building exterior walls within 10 feet (3048 mm) horizontally of a nonrated wall or unprotected opening in an interior exit stairway or ramp shall have a fire-resistance rating of not less than 1 hour. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. This construction shall extend vertically from the ground to a point 10 feet (3048 mm) above the topmost landing of the stairway or ramp, or to the roof line, whichever is lower.

    [BE] 1023.7.2 Roof assemblies. Where the interior exit stairway or ramp extends above an adjacent roof of the same building, the adjacent roof assembly shall have a fire-resistance rating of not less than 1 hour and openings shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. The fire-resistance rating and opening protection shall extend horizontally not less than 10 feet (3048 mm) from the exterior wall of the stairway or ramp, or to the perimeter of the adjacent roof, whichever is less.

    Exceptions:

    1. The roof assembly need not be rated and openings in the roof need not be protected where they are adjacent to the penthouse of the stairway or ramp, unless otherwise required by this code.
    2. The adjacent roof assembly need not be rated and adjacent openings in the roof need not be protected where the exterior wall of the stairway or ramp has a fire-resistance rating of 1 hour and openings are protected by opening protectives having a fire protection rating of not less than [3] / 4 hour, extending not less than 10 feet (3048 mm) above the roof.

    [BE] 1023.8 Barriers at level of exit discharge. An interior exit stairway and ramp shall not continue below its level of exit discharge unless an approved barrier is provided at the level of exit discharge to prevent persons from unintentionally continuing into levels below. Directional exit signs shall be provided as specified in Section 1013.

  • CHBC § 0.010 High relevance — show source text

    1. Fire protection systems.

    2. Security systems.

    3. Two-way communication systems.

    4. Electrical raceway for fire department communication systems.

    5. Electrical raceway serving the interior exit stairway and ramp and terminating at a steel box not exceeding 16 square inches (0.010 m [2] ).

    6. Structural elements, such as beams or joists, supporting the interior exit stairway or ramp or enclosure.

    7. Structural elements, such as beams or joists, supporting a roof at the top of the interior exit stairway or ramp.

    Such penetrations shall be protected in accordance with Section 714 of the California Building Code . There shall not be penetrations or communication openings, whether protected or not, between adjacent interior exit stairways and ramps.

    Exception: Membrane penetrations shall be permitted on the outside of the interior exit stairway and ramp. Such penetrations shall be protected in accordance with Section 714.4.2 of the California Building Code .

    [BE] 1023.6 Ventilation. Equipment and ductwork for interior exit stairway and ramp ventilation as permitted by Section 1023.5 shall comply with one of the following items:

    1. Such equipment and ductwork shall be located exterior to the building and shall be directly connected to the interior exit stairway and ramp by ductwork enclosed in construction as required for shafts.
    2. Where such equipment and ductwork is located within the interior exit stairway and ramp, the intake air shall be taken directly from the outdoors and the exhaust air shall be discharged directly to the outdoors, or such air shall be conveyed through ducts enclosed in construction as required for shafts.
    3. Where located within the building, such equipment and ductwork shall be separated from the remainder of the building, including other mechanical equipment, with construction as required for shafts.

    In each case, openings into the fire-resistance-rated construction shall be limited to those needed for maintenance and operation and shall be protected by opening protectives in accordance with Section 716 of the California Building Code for shaft enclosures.

    The interior exit stairway and ramp ventilation systems shall be independent of other building ventilation systems.

    [BE] 1023.7 Interior exit stairway and ramp exterior walls. Exterior walls of the interior exit stairway or ramp shall comply with the requirements of Section 705 of the California Building Code for exterior walls. Where nonrated walls or unprotected openings enclose the exterior of the stairway or ramps and the walls or openings are exposed by other parts of the building at an angle of less than 180 degrees (3.14 rad), building construction within 10 feet (3048 mm) of the exterior walls of the interior exit stairway or ramp shall comply with Sections 1023.7.1 and 1023.7.2.

    2025 CALIFORNIA FIRE CODE 10-47

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    MEANS OF EGRESS

    [BE] 1023.7.1 Building exterior walls. Building exterior walls within 10 feet (3048 mm) horizontally of a nonrated wall or unprotected opening in an interior exit stairway or ramp shall have a fire-resistance rating of not less than 1 hour. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. This construction shall extend vertically from the ground to a point 10 feet (3048 mm) above the topmost landing of the stairway or ramp, or to the roof line, whichever is lower.

  • CHBC § 1011.6.2 High relevance — show source text

    1011.6.2 Height and area for change to an equal or lesser-hazard category. Where a change of occupancy classification is made to an equal or lesser-hazard category as shown in Table 1011.6, the height and area of the existing buildingshall be deemed acceptable.

    1011.6.3 Fire barriers. Where a change of occupancy classification is made to a higher-hazard category as shown in Table 1011.6, fire barriers in separated mixed use buildings shall comply with the fire-resistance requirements of the California Building Code .

    Exception: Where the fire barriers are required to have a 1-hour fire-resistance rating, existing wood lath and plaster in good condition or existing [1] / 2 -inch-thick (12.7 mm) gypsum wallboard shall be permitted.

    1011.7 Exterior wall fire-resistance ratings. Hazard categories in regard to fire-resistance ratings of exterior walls shall be in accordance with Table 1011.7.

    TABLE 1011.7—EXPOSURE OF EXTERIOR WALLS HAZARD CATEGORIES Col2
    RELATIVE HAZARD OCCUPANCY CLASSIFICATION
    1 (Highest Hazard) H
    2 F-1; M; S-1
    3 A; B; E; I; R
    4 (Lowest Hazard) F-2; S-2; U

    2025 CALIFORNIA EXISTING BUILDING CODE 10-7

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    �

    �

    CHANGE OF OCCUPANCY

    1011.7.1 Exterior wall rating for change of occupancy classification to a higher-hazard category. Where a change of occupancy classification is made to a higher hazard category as shown in Table 1011.7, exterior walls shall have fire-resistance, exterior opening areas and opening protectives as required by the California Building Code .

    Exception: A 2-hour fire-resistance rating shall be allowed where the building does not exceed three stories in height and is classified as one of the following groups: A-2 and A-3 with an occupant load of less than 300, B, F, M or S.

    1011.7.2 Exterior wall rating for change of occupancy classification to an equal or lesser-hazard category. Where a change of occupancy classification is made to an equal or lesser-hazard category as shown in Table 1011.7, existing exterior walls, including openings, shall be accepted.

    1011.7.3 Opening protectives. Openings in exterior walls shall be protected as required by the California Building Code . Where openings in the exterior walls are required to be protected because of their distance from the lot line, the sum of the area of such openings shall not exceed 50 percent of the total area of the wall in each story.

    Exceptions:

    1. Where the California Building Code permits openings in excess of 50 percent.

    2. Protected openings shall not be required in buildings of Group R occupancy that do not exceed three stories in height and that are located not less than 3 feet (914 mm) from the lot line.

    3. Exterior opening protectives are not required where an automatic sprinkler system has been installed throughout.

    4. Exterior opening protectives are not required where the change of occupancy group is to an equal or lower hazard classification in accordance with Table 1011.7.

Frequently asked questions

Do the sprinklers have to be exterior or can they be inside and still meet § 8-402.1?

Either is allowed; the CHBC permits sprinklers to be installed on the exterior, and also contemplates systems that may be interior if they provide the required exposure protection — but the CHBC specifically requires at least one head over each opening and distribution along combustible walls under roof lines. § 8-402.1.

Which NFPA standard must I follow for exterior wall protection?

Use the NFPA standard identified in § 8-410.2 appropriate to your building (NFPA 13, 13R or 13D as the code lists); for exterior wall/opening protection the CHBC refers to the chapter requirements and the enforcing agency will require the appropriate NFPA standard and level of design. § 8-410.2.

Can a sprinkler shut‑off be installed on the system?

Yes — a shut‑off valve is permitted provided it is locked in an open position, per § 8-402.1.

Will installing exterior sprinklers let me remove required fire doors or exits?

No. The CHBC expressly states that automatic sprinkler systems shall not be used to substitute for or act as an alternate to the required number of exits. § 8-410.3.

Does the CHBC give exact head spacing and densities for these exterior sprinklers?

No. The CHBC requires placement (heads over openings and distribution along combustible walls) and references NFPA standards for system design. Exact spacing, hydraulics and densities are determined by the applicable NFPA standard and the enforcing agency’s plan review. § 8-402.1; § 8-410.2.

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