CEBC · California Existing Building Code

What are the smoke alarm and carbon monoxide detection requirements for alterations?

For homeowners: if your remodel or addition goes beyond a basic, cosmetic (Level 1) repair, the California Existing Building Code requires you to install or upgrade **smoke alarms** (for Group R and I‑1 occupancies) and usually **carbon monoxide alarms/detection**. The CEBC tells you *to follow* the California Fire Code (Section 915) and the California Residential Code (R310/R311) for exact locations, power and interconnect rules — check those sections for placement outside bedrooms, on every floor (including basements), interconnection, and listing requirements.

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

When an existing building in Group R or I‑1 is altered, added to, has a change of occupancy, or is relocated, the existing building must be provided with smoke alarms in accordance with the California Fire Code or the California Residential Code — see § 307.1 of the CEBC. Likewise, where an addition, alteration, change of occupancy or relocation occurs, the existing building must be provided with carbon monoxide (CO) detection in accordance with the California Fire Code or the California Residential Code — see § 308.1 of the CEBC. The CEBC also includes parallel, short-form adoption statements in § 307A and § 308A that require compliance with the California Building Standards Code for the same topics.

Most important: If your work is more than cosmetic (not Level 1 Alteration), adding or altering a Group R/I‑1 building triggers installation of smoke alarms (per § 307.1) and usually CO alarms/detection (per § 308.1), installed per the referenced building or fire code rules.

Requirements in detail

Which projects trigger the requirement

  • Trigger for smoke alarms: alteration, addition, change of occupancy, or relocation of an existing Group R or I‑1 building — § 307.1. Exception: Level 1 Alterations are exempt from § 307.1.
  • Trigger for CO detection: alteration, addition, change of occupancy, or relocation of an existing building — § 308.1. CEBC also directs CO detection in existing Group R per Health & Safety Code and the California Building/Residential Code — § 308.2.

Which technical standard applies

  • CEBC requires following either the California Fire Code (Chapter 9/Section 915 CO rules; Chapter 9 smoke alarm/detection rules) or the California Residential Code (smoke: Section R310; CO: Section R311/R315) as the technical installation and location standard. See § 307.1, § 308.1, § 307A, § 308A.

Key device/location/power/interconnect rules (from the referenced codes)

  • Locations for CO in dwellings: outside each separate sleeping area, on every occupiable level (including basements), and inside a bedroom if a CO source is in the bedroom — per the California Fire Code § 915 (and Residential Code R311).
  • CO alarms/devices must be listed (UL 2034 for residential CO alarms; detectors per UL 2075 if part of detection systems) and approved by Office of the State Fire Marshal. Power and interconnection rules are in the Fire Code/Residential Code (hard‑wired primary power with battery backup is generally required; limited exceptions exist for older buildings) — see Fire Code § 915 and R311 power/interconnect rules.

Decision table — triggers, what to install, and where

Trigger / Dimension Required device(s) Location / Coverage summary Power & interconnect summary Code Reference
Alteration / addition / change of occupancy / relocation to an existing Group R or I‑1 building (not Level 1) Smoke alarms Per California Fire Code or CRC Section R310 (typical: outside sleeping areas, on levels, etc.) Install per referenced code (often hard‑wired with battery backup; CRC/R310 and Fire Code govern) § 307.1
Alteration / addition / change of occupancy / relocation to any existing building Carbon monoxide detection Follow Fire Code §915 (dwellings: outside each sleeping area, every occupiable level; special rules for garages, furnaces, Group E) CO alarms listed; primary power from building wiring where available; interconnect where multiple alarms required (exceptions exist for pre‑2011 buildings) § 308.1, § 308.2
Minor/exterior repairs only (e.g., roofing, siding) Generally no new CO if work meets exception language in R311 / Fire Code See exceptions See exceptions CRC R311.2.2 exceptions; Fire Code interconnection exceptions

(For full location, power, listing and interconnect details, consult the California Fire Code Section 915 and the California Residential Code Section R311 cited above.)

Exceptions & special cases

  • Level 1 Alterations: Work classified as Level 1 under Chapter 7 is explicitly excepted from the smoke alarm requirement in § 307.1. If your scope is Level 1, smoke alarm upgrades are not required under that section.
  • Existing Group R – statewide CO requirement: Pursuant to Health and Safety Code Section 17926, all existing Group R buildings must have CO detection as required by CBC § 915 or CRC R315; CEBC § 308.2 references and enforces that requirement for existing portions.
  • Residential exceptions to adding CO for certain limited work: Where work is limited to exterior surfaces (roofing, siding, windows/doors, porch/deck), plumbing, or non‑fuel mechanical work, CRC R311.2.2 provides exceptions to adding CO alarms when an addition or fuel appliance is not being added.
  • Interconnect exceptions for older buildings: Interconnection of multiple CO alarms (or smoke/CO combination alarms) is not required in existing buildings built prior to January 1, 2011 if the work does not remove interior finishes exposing structure or if wireless listed alarms are used — see Fire Code § 915 and CRC interconnect exception.
  • Where Fire Code requires detectors (not alarms): In some non‑residential spaces the Fire Code requires detectors (connected to fire alarm systems) rather than stand‑alone CO alarms (see Fire Code § 915 for distinctions and locations such as Group E, enclosed garages, or spaces with forced‑air CO‑producing furnaces).

If a CEBC section here points you to the California Fire Code or Residential Code (for example § 307.1 or § 308.1), the detailed placement/power/listing rules you must follow are contained in those referenced sections — inspect those referenced sections for final technical requirements.

Common mistakes

  • Assuming any minimal repair triggers nothing — some repairs are Level 2/3 in practice and do trigger alarm requirements; only Level 1 is exempt under § 307.1.
  • Omitting CO detection for attached garages or when adding a fuel‑burning appliance — these are common triggers per Fire Code § 915 and CRC R311.2.1/2.2.
  • Failing to use listed devices or failing to follow Office of the State Fire Marshal listing/approval — the Fire Code and Residential Code require listed devices (e.g., UL 2034 / UL 2075) and OSFM approval.
  • Not interconnecting alarms where required; assuming battery‑only is always allowed — the codes require hard‑wired primary power with battery backup in many situations; limited exceptions apply for older buildings and limited work scopes. Check interconnection/power rules in CRC R311 and Fire Code § 915.

Worked example — concrete scenario

Scenario: A two‑story duplex (Group R‑2) built in 2005 is undergoing an interior remodel that removes interior wall finishes on both floors (so this is more than a Level 1 repair). The owner also installs a new gas‑fired water heater in the basement and closes in an existing open porch to create an occupiable room.

How the rules apply:

  1. Smoke alarms — Because this is an alteration (not Level 1) to a Group R building, smoke alarms must be provided per § 307.1 and installed per the California Fire Code or CRC R310 (e.g., smoke alarms outside sleeping areas and on each level).
  2. CO detection — The addition of a fuel‑fired water heater and the fact the building has occupiable spaces require CO detection. Install CO alarms outside each separate sleeping area and on every occupiable level (basement included) per Fire Code § 915 / CRC R311.3. Because the remodel removed interior finishes (providing access), required alarms must be interconnected if multiple are required (per R311.5 / Fire Code § 915.4.4) and powered per the referenced code (hard‑wired where building wiring is available with battery backup).
  3. Listing/installation — Use OSFM‑approved/listed CO devices (UL 2034 for residential CO alarms or UL 2075 for detectors if a system), and follow manufacturer instructions and NFPA 72 where required.

Bottom line for the example: Provide smoke alarms per § 307.1 and CO alarms per § 308.1 / referenced code sections; place CO alarms outside bedrooms and on each floor including basement; interconnect and power as required by the Residential/Fire Code.

Related provisions (CEBC)

  • § 307 — Smoke alarms (CEBC).
  • § 308 — Carbon monoxide detection (CEBC).
  • § 307A — Smoke alarms (adoption statement; CEBC A‑chapter).
  • § 308A — Carbon monoxide detection (adoption statement; CEBC A‑chapter).
  • § 501.5 — Carbon monoxide alarms / existing Group R occupancies references elsewhere in CEBC.
  • Referenced technical standards you must consult for locations/power/listing/interconnect: California Fire Code § 915 and the California Residential Code Sections R310 / R311 (R315 as applicable) — CEBC points you to these sections for the technical details.

Code references

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

  • CEBC § 304.3.3 High relevance — show source text

    304.3.3 Criteria for incidental and minor structural alteration, additions, or repairs of pre-1973 code buildings. [OSHPD 1R, 2, 4 & 5] Provisions of this section shall apply to hospital buildings which were originally designed to pre-1973 building codes, and had no major structural alterations, additions or repairs using 1973 California Building Standards Code or later editions with an OSHPD permit. 1. Nonstructural components. Component importance factor, I p , shall be permitted to be 1.0. Exception: Components required for life safety purposes after an earthquake, including emergency, standby or alternative power systems, mechanical smoke removal systems, fire protection sprinkler systems, fire alarm control panels and egress stairways shall have a component importance factor (I p ) of 1.5.

    SECTION 305—IN-SITU LOAD TESTS

    [BS] 305.1 General. Where used, in-situ load tests shall be conducted in accordance with Section 1708 of the California Building Code .

    SECTION 306—ACCESSIBILITY FOR EXISTING BUILDINGS

    [DSA-AC] Public buildings, public accommodations, commercial facilities and public housing regulated by the Division of the State Architect-Access Compliance in Title 24, Part 2, California Building Code, Chapter 1, Section 1.9.1 shall comply with Title 24, Part 2, California Building Code, Chapter 11B.

    [HCD 1-AC] Accessibility requirements for covered multifamily dwellings, as defined in Chapter 2 of the California Building Code, are promulgated under HCD authority and are located in Chapter 11A of the California Building Code.

    SECTION 307—SMOKE ALARMS

    307.1 Smoke alarms. Where an alteration, addition, change of occupancy or relocation of a building is made to an existing building or structure of a Group R and I-1 occupancy, the existing building shall be provided with smoke alarms in accordance with the California Fire Code or Section R310 of the California Residential Code .

    Exception: Work classified as Level 1 Alterations in accordance with Chapter 7.

    SECTION 308—CARBON MONOXIDE DETECTION

    308.1 Carbon monoxide detection. Where an addition, alteration, change of occupancy or relocation of a building is made to an existing building, the existing building shall be provided with carbon monoxide detection in accordance with the California Fire Code or Section R311 of the California Residential Code .

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    308.2 Carbon monoxide alarms in existing portions of a building. [HCD 1 & HCD 2] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Residential Code, as applicable.

  • CEBC § 307.1 High relevance — show source text

    [HCD 1-AC] Accessibility requirements for covered multifamily dwellings, as defined in Chapter 2 of the California Building Code, are promulgated under HCD authority and are located in Chapter 11A of the California Building Code.

    SECTION 307—SMOKE ALARMS

    307.1 Smoke alarms. Where an alteration, addition, change of occupancy or relocation of a building is made to an existing building or structure of a Group R and I-1 occupancy, the existing building shall be provided with smoke alarms in accordance with the California Fire Code or Section R310 of the California Residential Code .

    Exception: Work classified as Level 1 Alterations in accordance with Chapter 7.

    SECTION 308—CARBON MONOXIDE DETECTION

    308.1 Carbon monoxide detection. Where an addition, alteration, change of occupancy or relocation of a building is made to an existing building, the existing building shall be provided with carbon monoxide detection in accordance with the California Fire Code or Section R311 of the California Residential Code .

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    308.2 Carbon monoxide alarms in existing portions of a building. [HCD 1 & HCD 2] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Residential Code, as applicable.

    308.2.1 Carbon monoxide detection in existing Group E occupancy buildings. Where the new addition includes any of the conditions identified in the California Fire Code Sections 915.1.2 through 915.1.6, carbon monoxide detection shall be installed in accordance with Section 915 of the California Fire Code. No person shall install, market, distribute, offer for sale, or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.

    SECTION 309—ADDITIONS AND REPLACEMENTS OF EXTERIOR WALL COVERINGS AND EXTERIOR WALL ENVELOPES

    309.1 General. The provisions of Section 309 apply to all alterations, repairs, additions, relocations of structures and changes of occupancy regardless of compliance method.

    309.2 Additions and replacements. Where an exterior wall covering or exterior wall envelope is added or replaced, the materials and methods used shall comply with the requirements for new construction in Chapter 14 and Chapter 26 of the California Building Code if the added or replaced exterior wall covering or exterior wall envelope involves two or more contiguous stories and comprises more than 15 percent of the total wall area on any side of the building.

    309.2.1 Automatic sprinkler systems. Combustible exterior wall covering or combustible exterior wall envelopes shall not be added to an existing high-rise building that is not protected throughout with an automatic sprinkler system.

    Exceptions:

    1. Where such material is located on a single story and is less than 15 percent of the wall area on any side of the building.
    2. Water-resistive barriers installed in accordance with Section 1402.6 of the California Building Code .
  • CEBC § 1.2 High relevance — show source text

    No person shall install, market, distribute, offer for sale or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.

    R311.1.2 Installation. Carbon monoxide alarms, and combination carbon monoxide and smoke alarms, shall be installed in accordance with their listing and the manufacturer’s instructions.

    R311.2 Where required. Carbon monoxide alarms shall be provided in accordance with Sections R311.2.1 and R311.2.2.

    Pursuant to Health and Safety Code Section 17926, carbon monoxide devices shall be installed in all existing dwelling units as required in this section.

    R311.2.1 Existing buildings and new construction. For existing buildings and new construction, carbon monoxide alarms shall be provided in dwelling units where either or both of the following conditions exist.

    1. The dwelling unit contains a fuel-fired appliance or fireplace.
    2. The dwelling unit has an attached garage with an opening that communicates with the dwelling unit.

    R311.2.2 Alterations, repairs and additions. Where an addition is made to an existing dwelling, or a fuel-burning heater, appli- ance or fireplace is added to an existing dwelling, not previously required to be provided with carbon monoxide alarms, new carbon monoxide alarms shall be installed in accordance with Section R311.

    Exceptions:

    1. Work involving the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck.
    2. Installation, alteration or repairs of plumbing systems.
    3. Installation, alteration or repairs of mechanical systems that are not fuel fired.

    R311.3 Location. Carbon monoxide alarms in dwelling units shall be installed and maintained in accordance with the manufacturer’s published instructions in the following locations: 1. Outside of each separate sleeping area in the immediate vicinity of the bedrooms. 2. On every occupiable level of a dwelling unit, including basements. 3. Where a fuel-burning appliance is located within a bedroom or its attached bathroom, a carbon monoxide alarm shall be installed within the bedroom.

    R311.4 Combination alarms. Combination carbon monoxide and smoke alarms shall be permitted to be used in lieu of carbon monoxide alarms.

    Combination carbon monoxide/smoke alarms shall comply with Section R311 and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    R311.5 Interconnectivity. Where more than one carbon monoxide alarm is required to be installed within an individual dwelling unit in accordance with Section R311.3, the alarm devices shall be interconnected in such a manner that the actuation of one alarm will activate all of the alarms in the individual dwelling unit. Physical interconnection of carbon monoxide alarms shall not be required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.

    Exception: Interconnection of carbon monoxide alarms in existing buildings built prior to January 1, 2011, shall not be required under any of the following conditions: 1. Where alterations or repairs do not result in removal of interior wall or ceiling finishes exposing the structure, unless there is an attic, crawl space or basement available that could provide access for interconnection without the removal of interior finishes.

  • CEBC § 915.4.2 High relevance — show source text

    Exceptions:

    1. Where installed in buildings without commercial power, battery-powered carbon monoxide alarms shall be an acceptable alternative. 2. Carbon monoxide alarms in Group R occupancies shall be permitted to receive their primary power from other power sources recognized for use by NFPA 720. 3. Carbon monoxide alarms in Group R occupancies shall be permitted to be battery-powered or plug-in with a battery backup in existing buildings built prior to January 1, 2011, under any of the following conditions: 3.1. No construction is taking place. 3.2. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 3.3. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 3.4. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    915.4.2 Listings. Residential carbon monoxide alarms shall be listed in accordance with UL 2034.

    No person shall install, market, distribute, offer for sale or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.

    915.4.3 Combination alarms. Combination carbon monoxide/smoke alarms shall be an acceptable alternative to carbon monoxide alarms. Combination carbon monoxide/smoke alarms shall be listed in accordance with UL 217 and UL 2034. Combination carbon monoxide/smoke alarms shall comply with Section 915, and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    915.4.4 Interconnection. Where more than one carbon monoxide alarm is required to be installed within a dwelling unit or within a sleeping unit in Group R occupancies, the alarms shall be interconnected in a manner that activation of one alarm shall activate all of the alarms in the individual unit.

    Exception : Interconnection is not required in existing buildings, built prior to January 1, 2011, under any of the following conditions: 1. Physical interconnection is not required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.

    2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.

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  • CEBC § 915.4.4 High relevance — show source text

    915.4.4 Interconnection. Where more than one carbon monoxide alarm is required to be installed within a dwelling unit or within a sleeping unit in Group R occupancies, the alarms shall be interconnected in a manner that activation of one alarm shall activate all of the alarms in the individual unit.

    Exception : Interconnection is not required in existing buildings, built prior to January 1, 2011, under any of the following conditions: 1. Physical interconnection is not required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.

    2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    915.5.1 General. Carbon monoxide detectors shall be listed in accordance with UL 2075.

    915.5.2 Locations. Carbon monoxide detectors shall be installed in the locations specified in Section 915.2. These locations supersede the locations specified in NFPA 72.

    915.5.3 Combination detectors. Combination carbon monoxide/smoke detectors shall be an acceptable alternative to carbon monoxide detectors, provided that they are listed in accordance with UL 268 and UL 2075.

    Combination carbon monoxide/smoke alarms shall comply with Section 915, and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    915.5.4 Occupant notification. Activation of a carbon monoxide detector shall annunciate at the control unit and shall initiate audible and visible alarm notification throughout the building.

    Exception: Occupant notification is permitted to be limited to the area where the carbon monoxide alarm signal originated and other signaling zones in accordance with the fire safety plan, provided that the alarm signal from an activated carbon monoxide detector is automatically transmitted to an approved on-site location or off-premises location.

    915.5.5 Duct detection. Carbon monoxide detectors placed in environmental air ducts or plenums shall not be used as a substitute for the required protection in Section 915.

    915.6 Maintenance. Carbon monoxide alarms and carbon monoxide detection systems shall be maintained in accordance with NFPA 72. Carbon monoxide alarms and carbon monoxide detectors that become inoperable or begin producing end-of-life signals shall be replaced.

  • CEBC § 9-57 High relevance — show source text

    which do_ not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    [F] 915.4.2 Listings. Residential Carbon monoxide alarms shall be listed in accordance with UL 2034.

    No person shall install, market, distribute, offer for sale, or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.

    [F] 915.4.3 Combination alarms. Combination carbon monoxide/smoke alarms shall be an acceptable alternative to carbon monoxide alarms. Combination carbon monoxide/smoke alarms shall be listed in accordance with UL 217 and UL 2034.

    Combination carbon monoxide/smoke alarms shall comply with Section 915, and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    [F] 915.4.4 Interconnection. Where more than one carbon monoxide alarm is required to be installed within a dwelling unit or within a sleeping unit in Group R occupancies, the alarms shall be interconnected in a manner that activation of one alarm shall activate all of the alarms in the individual unit.

    Exception: Interconnection is not required in existing buildings, built prior to January 1, 2011, under any of the following conditions:

    1. Physical interconnection is not required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.

    2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    [F] 915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.

    [F] 915.5.1 General. Carbon monoxide detectors shall be listed in accordance with UL 2075.

    [F] 915.5.2 Locations. Carbon monoxide detectors shall be installed in the locations specified in Section 915.2 or NFPA 72.

    [F] 915.5.3 Combination detectors. Combination carbon monoxide/smoke detectors shall be an acceptable alternative to carbon monoxide detectors, provided that they are listed in accordance with UL 268 and UL 2075.

    Combination carbon monoxide/smoke detectors shall comply with all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    [F] 915.5.4 Occupant notification. Activation of a carbon monoxide detector shall annunciate at the control unit and shall initiate audible and visible alarm notification throughout the building.

  • CEBC § 3A-9 High relevance — show source text

    305 A .1 General. Where used, in-situ load tests shall be conducted in accordance with Section 1708 A of the California Building Code .

    SECTION 306 A —ACCESSIBILITY FOR EXISTING BUILDINGS

    306 A .1 Scope. Accessibility requirements for existing buildings shall comply with the California Building Code, Part 2, Volume 1, Chapter 11B.

    SECTION 307 A —SMOKE ALARMS

    Shall comply with the California Building Standards Code.

    SECTION 308 A —CARBON MONOXIDE DETECTION

    Shall comply with the California Building Standards Code.

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    SECTION 309 A — RESERVED

    SECTION 310A — COMPLIANCE ALTERNATIVES FOR SERVICES/SYSTEMS AND UTILITIES

    310A.1 General. The provisions of this section are intended to maintain or increase the current degree of public safety, health and general welfare in existing buildings while permitting repair, alteration, addition and change of occupancy without requiring full compli- ance with California Building Code Chapters 2 through 33, or Sections 302A.3 and 502A through 506A, except where compliance with other provisions of this code is specifically required in this section.

    Services/systems and utilities that originate in and pass through or under buildings and are necessary to the operation of the hospital buildings shall meet the structural requirements of this section. Examples of services/systems and utilities include but are not limited to normal power; emergency power; nurse call; fire alarm; communication and data systems; space-heating systems; process load systems; cooling systems; domestic hot and cold water systems; means of egress systems; fire-suppression systems; building drain and sewer systems; and medical gas systems that support basic and supplemental services.

    After January 1, 2030, services/systems and utilities for acute care hospital buildings shall not originate in or pass through or under a nonhospital or hospital building unless it has approved performance categories of SPC-3 or higher and NPC-5.

    310A.1.1 Services/systems and utilities. Services/systems and utilities that are necessary to the operation of the hospital buildings shall meet the structural requirements of this section, based upon the approved Structural Performance Category (SPC) of the build- ing receiving the services/systems and utilities.

    Services from a conforming building shall be permitted to serve a nonconforming building with prior approval of the Office. The services/systems and utilities in the nonconforming building shall be equipped with fail safe valves, switches or other equivalent devices that allow the nonconforming building to be isolated from the conforming building.

    Exception: Remodel projects that use available existing services/systems and utilities are exempted from the requirements of this section. The enforcing agency shall be permitted to exempt minor addition, minor alteration and minor remodel projects and proj- ects to upgrade existing services/systems and utilities from the requirements of this section.

    310A.1.1.1 Services/systems and utilities for hospital buildings.

  • CEBC § 915.5 High relevance — show source text

    2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    [F] 915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.

    [F] 915.5.1 General. Carbon monoxide detectors shall be listed in accordance with UL 2075.

    [F] 915.5.2 Locations. Carbon monoxide detectors shall be installed in the locations specified in Section 915.2 or NFPA 72.

    [F] 915.5.3 Combination detectors. Combination carbon monoxide/smoke detectors shall be an acceptable alternative to carbon monoxide detectors, provided that they are listed in accordance with UL 268 and UL 2075.

    Combination carbon monoxide/smoke detectors shall comply with all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    [F] 915.5.4 Occupant notification. Activation of a carbon monoxide detector shall annunciate at the control unit and shall initiate audible and visible alarm notification throughout the building.

    Exception: Occupant notification is permitted to be limited to the area where the carbon monoxide alarm signal originated and other signaling zones in accordance with the fire safety plan, provided that the alarm signal from an activated carbon monoxide detector is automatically transmitted to an approved on-site location or off-premises location.

    [F] 915.5.5 Duct detection. Carbon monoxide detectors placed in environmental air ducts or plenums shall not be used as a substitute for the required protection in Section 915.

    [F] 915.6 Maintenance. Carbon monoxide alarms and carbon monoxide detection systems shall be maintained in accordance with NFPA 72. Carbon monoxide alarms and carbon monoxide detectors that become inoperable or begin producing end-of-life signals shall be replaced.

    915.6.1 Enclosed parking garages. Carbon monoxide and nitrogen dioxide detectors installed in enclosed parking garages in accor- dance with Section 403.7.2 of the California Mechanical Code shall be maintained in accordance with the manufacturer’s instructions and their listing. Detectors that become inoperable or begin producing end-of-life signals shall be replaced.

    915.7 Visible alarms. In buildings containing covered multifamily dwellings as defined in Chapter 2, all required carbon monoxide alarms shall be equipped with the capability to support visible alarm notification in accordance with NFPA 72.

    SECTION 916—GAS DETECTION SYSTEMS

    [F] 916.1 Gas detection systems. Gas detection systems required by this code shall comply with Sections 916.2 through 916.11.

    [F] 916.2 Permits. Permits shall be required as set forth in Section 105.6.10 of the California Fire Code .

  • CEBC § 501.3 High relevance — show source text

    Plans, investigation and evaluation reports, and other data shall be submitted indicating which building elements and materials the applicant is requesting the code official to review and approve for determination of applying the current building code fire-resistance ratings. Any special construction features, including fire-resistance-rated assemblies and smoke-resistive assemblies, conditions of occupancy, means of egress conditions, fire code deficiencies, approved modifications or approved alternative materials, design and methods of construction, and equipment applying to the building that impact required fire-resistance ratings shall be identified in the evaluation reports submitted.

    501.3 Health care facilities. In Group I-2 facilities, ambulatory care facilities and outpatient clinics, any altered or added portion of an existing electrical or medical gas systems shall be required to meet installation and equipment requirements in NFPA 99.

    501.4 Existing Group R occupancies. [SFM] See the California Residential Code for existing Group R-3 occupancies or Chapter 11 of the California Fire Code for all other existing Group R occupancies.

    501.5 Carbon monoxide alarms. [HCD 1, SFM] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Resi- dential Code, as applicable.

    501.5.1 Carbon monoxide detection in alterations to an existing Group E building. Where the alteration adds any of the condi- tions identified in the California Fire Code Sections 915.1.2 through 915.1.6 to an existing Group E building, not previously required to be provided with carbon monoxide detection, new carbon monoxide detection shall be installed in accordance with Section 915 of the California Fire Code.

    Exceptions: 1. The alteration replaces an existing fossil-fuel burning appliance, fireplace or forced-air furnace, or any of the conditions identified in Sections 915.1.2 through 915.1.6 are already present. 2. The Group E building was constructed before the adoption of the 2016 California Building Standards Code.

    SECTION 502—ADDITIONS

    502.1 General. Additions to any building or structure shall comply with the requirements of the California Building Code or California Residential Code, as applicable, for new construction. Alterations to the existing building or structure shall be made to ensure that

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    PRESCRIPTIVE COMPLIANCE METHOD

    the existing building or structure together with the addition are not less complying with the provisions of the California Building Code than the existing building or structure was prior to the addition except that the structural elements need only comply with Sections 502.2 through 502.3 . An existing building together with its additions shall comply with the height and area provisions of Chapter 5 of the California Building Code . Where a new occupiable roof is added to a building or structure, the occupiable roof shall comply with the provisions of the California Building Code. [OSHPD 1R, 2, 4 & 5] Structural elements shall comply with all the provisions of Section 502.

  • CEBC § 915.3 High relevance — show source text

    Exception: Where environmental conditions prohibit the installation of carbon monoxide detector in an enclosed room or space, carbon monoxide detectors shall be installed in an approved enclosed location contiguous with the room or space that contains a CO source.

    [F] 915.3 Carbon monoxide detection. Carbon monoxide detection required by Sections 915.1 through 915.2.3 shall be provided by carbon monoxide alarms complying with Section 915.4 or carbon monoxide detection systems complying with Section 915.5.

    [F] 915.3.1 Alarm limitations. Carbon monoxide alarms shall only be installed in dwelling units and in sleeping units. They shall not be installed in locations where the code requires carbon monoxide detectors to be used.

    [F] 915.3.2 Fire alarm system required. New buildings that are required by Section 907.2 to have a fire alarm system and by Section 915.2 to have carbon monoxide detectors shall be connected to the fire alarm system in accordance with NFPA 72.

    [F] 915.3.3 Fire alarm systems not required. In new buildings that are not required by Section 907.2 to have a fire alarm system, carbon monoxide detection shall be provided by one of the following:

    1. Carbon monoxide detectors connected to an approved carbon monoxide detection system in accordance with NFPA 72.
    2. Carbon monoxide detectors connected to an approved combination system in accordance with NFPA 72.
    3. Carbon monoxide detectors connected to an approved fire alarm system in accordance with NFPA 72.
    4. Where approved by the fire code official, carbon monoxide alarms maintained in accordance with the manufacturer’s instructions.

    [F] 915.3.4 Installation. Carbon monoxide detection shall be installed in accordance with NFPA 72 and the manufacturer’s instructions.

    [F] 915.4 Carbon monoxide alarms. Carbon monoxide alarms shall comply with Sections 915.4.1 through 915.4.5 .

    [F] 915.4.1 Power source. Carbon monoxide alarms shall receive their primary power from the building wiring where such wiring is served from a commercial source, and when primary power is interrupted, shall receive power from a battery. Wiring shall be permanent and without a disconnecting switch other than that required for overcurrent protection.

    Exception s :

    1. Where installed in buildings without commercial power, battery-powered carbon monoxide alarms shall be an acceptable alternative. 2. Carbon monoxide alarms in Group R occupancies shall be permitted to receive their primary power from other power sources recognized for use by NFPA 72. 3. Carbon monoxide alarms in Group R occupancies shall be permitted to be battery-powered or plug-in with a battery backup in existing buildings built prior to January 1, 2011, under any of the following conditions: 3.1. No construction is taking place. 3.2. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 3.3. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 3.4. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

  • CEBC § 915.2.5 High relevance — show source text

    915.2.5 Private garages. Carbon monoxide detection complying with Item 3 of Section 915.1.1 shall be installed within enclosed occupiable rooms or spaces that are contiguous to the attached private garage.

    Exceptions:

    1. In buildings without communicating openings between the private garage and the building.
    2. In rooms or spaces located more than one story above or below a private garage.
    3. Where the private garage connects to the building through an open-ended corridor.
    4. An open parking garage complying with Section 406.5 of the California Building Code or an enclosed parking garage complying with Section 406.6 of the California Building Code shall not be considered a private garage.
    5. Dwelling units that comply with Section 915.2.1.

    915.2.6 All other occupancies. For locations other than those specified in Sections 915.2.1 through 915.2.5, carbon monoxide detectors shall be installed on the ceiling of enclosed rooms or spaces containing CO-producing devices or served by a CO source forced-air furnace.

    Exception: Where environmental conditions prohibit the installation of carbon monoxide detector in an enclosed room or space, carbon monoxide detectors shall be installed in an approved enclosed location contiguous with the room or space that contains a CO source.

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    915.3 Carbon monoxide detection. Carbon monoxide detection required by Sections 915.1 through 915.2.3 shall be provided by carbon monoxide alarms complying with Section 915.4 or carbon monoxide detection systems complying with Section 915.5.

    915.3.1 Alarm limitations. Carbon monoxide alarms shall only be installed in dwelling units and in sleeping units. They shall not be installed in locations where the code requires carbon monoxide detectors to be used.

    915.3.2 Fire alarm system required. New buildings that are required by Section 907.2 to have a fire alarm system and by Section 915.2 to have carbon monoxide detectors shall be connected to the fire alarm system in accordance with NFPA 72.

    915.3.3 Fire alarm systems not required. In new buildings that are not required by Section 907.2 to have a fire alarm system, carbon monoxide detection shall be provided by one of the following:

    1. Carbon monoxide detectors connected to an approved carbon monoxide detection system in accordance with NFPA 72.
    2. Carbon monoxide detectors connected to an approved combination system in accordance with NFPA 72.
    3. Carbon monoxide detectors connected to an approved fire alarm system in accordance with NFPA 72.
    4. Where approved by the fire code official, carbon monoxide alarms maintained in accordance with the manufacturer’s instructions.

    915.3.4 Installation. Carbon monoxide detection shall be installed in accordance with NFPA 72 and the manufacturer’s instructions.

    915.4 Carbon monoxide alarms. Carbon monoxide alarms shall comply with Sections 915.4.1 through 915.4.4.

    915.4.1 Power source. Carbon monoxide alarms shall receive their primary power from the building wiring where such wiring is served from a commercial source, and when primary power is interrupted, shall receive power from a battery. Wiring shall be permanent and without a disconnecting switch other than that required for overcurrent protection.

    Exceptions:

  • CEBC § 2.2 High relevance — show source text

    R311.6 Power source. Carbon monoxide alarms shall receive their primary power from the building wiring where such wiring is served from a commercial source and, where primary power is interrupted, shall receive power from a battery. Wiring shall be permanent and without a disconnecting switch other than those required for overcurrent protection.

    Exceptions:

    1. Carbon monoxide alarms shall be permitted to be battery operated where installed in buildings without commercial

    power. 2. Carbon monoxide alarms installed in accordance with Section R311.2.2 shall be permitted to be battery powered.

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    BUILDING PLANNING

    3. Carbon monoxide alarms in Group R occupancies shall be permitted to receive their primary power from other power sources recognized for use by NFPA 72. 4. Carbon monoxide alarms in Group R occupancies shall be permitted to be battery-powered or plug-in with a battery backup in existing buildings built prior to January 1, 2011, under any of the following conditions: 4.1. No construction is taking place. 4.2. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4.3. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 4.4. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.

    R311.7 Carbon monoxide detection systems. Carbon monoxide detection systems shall be permitted to be used in lieu of carbon monoxide alarms and shall comply with Sections R311.7.1 through R311.7.4.

    R311.7.1 General. Household carbon monoxide detection systems shall comply with NFPA 72. Carbon monoxide detectors shall be listed in accordance with UL 2075.

    R311.7.2 Location. Carbon monoxide detectors shall be installed and maintained in the locations specified in Section R311.3 or NFPA 72.

    R311.7.3 Permanent fixture. Where a household carbon monoxide detection system is installed, it shall become a permanent fixture of the occupancy and owned by the homeowner.

    R311.7.4 Combination detectors. Combination carbon monoxide and smoke detectors installed in carbon monoxide detection systems in lieu of carbon monoxide detectors shall be listed in accordance with UL 268 and UL 2075.

    Combination carbon monoxide/smoke detectors shall comply with all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.

    SECTION R312—MINIMUM ROOM AREAS

    R312.1 Minimum area. Habitable rooms shall have a floor area of not less than 70 square feet (6.5 m [2] ).

    Exception: Kitchens.

    R312.2 Minimum dimensions. Habitable rooms shall be not less than 7 feet (2134 mm) in any horizontal dimension.

    Exceptions:

    1. Kitchens.

    2. Limited-density owner-built rural dwellings. See Section R301.1.1.1.

Frequently asked questions

When does a small interior remodel require new smoke alarms?

If the remodel is more than a Level 1 Alteration (i.e., not the minimal exterior or cosmetic work exempted), § 307.1 applies and smoke alarms must be provided per the referenced codes.

Do I always need CO alarms when I add a gas appliance?

Yes — adding a fuel‑burning appliance to an existing dwelling typically triggers CO alarm installation per R311.2.2 and CEBC § 308.1; place alarms per R311 / Fire Code § 915.

Can I use battery‑only CO alarms in an older building?

There are limited exceptions for existing buildings built before January 1, 2011 where battery or plug‑in devices may be permitted if the work scope qualifies (no removal of interior finishes, limited exterior work, etc.). See Fire Code § 915 and CRC R311 exceptions.

Are combination smoke/CO alarms acceptable?

Yes — the codes allow combination smoke/CO alarms if they are listed for both functions and meet the listing/OSFM requirements referenced in the Fire Code and Residential Code.

If I only replace siding or roofing, do I need to add CO alarms?

Generally no — CRC R311.2.2 and Fire Code exceptions exclude limited exterior work (roofing, siding, windows/doors, porch/deck) from the CO alarm trigger when no fuel appliance or other trigger condition is added.

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California Existing Building Code