CRC · California Residential Code
What referenced standards apply to smoke and carbon monoxide detection and alarms?
Homeowners: The California Residential Code requires whole-house carbon monoxide systems to meet **NFPA 72** and individual CO detectors to be **listed to UL 2075**, and it directs you to install those devices where **Section R311.3** (outside bedrooms and on every occupiable level) or NFPA 72 require.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
Household carbon monoxide detection systems used in lieu of standalone alarms must comply with NFPA 72, and individual carbon monoxide detectors must be listed to UL 2075 — § R311.7.1. Placement of those detectors is required as specified in Section R311.3 or NFPA 72 — § R311.7.2. These are the controlling CRC provisions for carbon monoxide detection systems and their location.
The single most important rule: Household carbon monoxide detection systems must meet NFPA 72, and CO detectors must be listed to UL 2075 and installed where Section R311.3 or NFPA 72 require.
Requirements in detail
1) Referenced standards (what the code points to)
- NFPA 72 — required for household carbon monoxide detection systems (performance, system design, interconnection and notification when a detection system is used) — § R311.7.1.
- UL 2075 — required listing standard for carbon monoxide detectors (single-purpose detectors) — § R311.7.1.
Note: Where a CO detector is provided as a combination device, other listing standards apply (see Related provisions). The CRC allows device location per Section R311.3 or NFPA 72 — § R311.7.2.
2) Decision table — which standard applies to which device or system
| Decision dimension | Required value / threshold | Code Reference |
|---|---|---|
| Household CO detection system (whole-house system) | Must comply with NFPA 72 | § R311.7.1 |
| Single-purpose CO detector (standalone alarm) | Must be listed to UL 2075 | § R311.7.1 |
| Combination CO + smoke detector used in a CO detection system | Combination devices must be listed to UL 268 and UL 2075 when used in a system | § R311.7.4 (related) |
| Location of CO detectors | Installed and maintained where Section R311.3 or NFPA 72 specify (e.g., outside each sleeping area, on every occupiable level) | § R311.7.2 and § R311.3 |
| Installation practice | Installed in accordance with the device listing and manufacturer instructions (and NFPA 72 when a system is used) | § R311.1.2 and § R311.7.1 / R311.7.2 |
3) How the standards interact with CRC requirements
- The CRC does not replace testing/listing requirements — it mandates which outside standards the system or device must meet: NFPA 72 for systems and UL 2075 for CO detector listings — § R311.7.1.
- For device placement, the CRC defers to its own Section R311.3 locations (explicit residential locations such as outside each separate sleeping area and on every occupiable level) or to NFPA 72 for system installations — § R311.7.2.
Exceptions & special cases
- The CRC text for R311.7.1 and R311.7.2 provides the referenced standards but does not list exceptions to the referenced standards themselves. Use NFPA 72 and the device listing for any allowed variations. § R311.7.1 and § R311.7.2 are the controlling CRC cross‑references.
- Combination devices and system-level features: combination CO/smoke devices used in a CO detection system must meet the combination listing standards (UL 268 and UL 2075) and comply with Office of the State Fire Marshal approval for smoke alarms — see § R311.7.4 (related).
- The CRC also provides location and interconnection specifics elsewhere (for example, § R311.3 for locations and § R311.5 for interconnection requirements) — consult those sections when applying NFPA 72 locations or system interconnect requirements.
If you need variants or local fire code requirements (for example, when buildings are covered by the California Fire Code rather than just the CRC), those codes contain related but not identical provisions — review the Fire Code Section 915 series for larger or non-residential systems.
Common mistakes
- Assuming any CO alarm will do: CO alarms must be listed to the correct standard (UL 2075 for CO detectors; system devices must comply with NFPA 72) — § R311.7.1.
- Installing devices only where convenient rather than where required: the CRC requires locations per Section R311.3 or NFPA 72 — e.g., outside each sleeping area and on every occupiable level — § R311.7.2 and § R311.3.
- Overlooking combination-device listing differences: combination CO/smoke devices used in systems must meet both CO and smoke listing standards (UL 2075 and UL 268, and Office of the State Fire Marshal approval for smoke alarms) — see § R311.7.4.
- Forgetting manufacturer instructions or listing installation requirements: the CRC requires installation in accordance with the device’s listing and manufacturer’s instructions — § R311.1.2.
Worked example — concrete scenario
Scenario: A two-story single-family dwelling with an attached garage and a fuel-fired furnace in the utility room.
- Does the unit require CO protection? Yes — dwelling contains a fuel-fired appliance and has an attached garage, so CO alarms are required per § R311.2.1.
- What listing/standard is required for devices? Choose carbon monoxide detectors listed to UL 2075 (if you use standalone alarms) or install a household CO detection system that complies with NFPA 72 — § R311.7.1.
- Where to install? Follow Section R311.3: at least one CO alarm outside each separate sleeping area and on every occupiable level, including the basement (if present); additionally, if a fuel-burning appliance is in a bedroom, one must be inside that bedroom — § R311.7.2 referencing § R311.3. For this two-story home with bedrooms upstairs and living space downstairs, install: one CO alarm outside the upstairs bedrooms, one on the ground floor/living area (every occupiable level), and one near the furnace/garage path if required by manufacturer/NFPA 72.
- Interconnection and power: If more than one alarm is required in the dwelling, interconnect so that activation of one alarm triggers all (subject to existing-building exceptions). If hard‑wired, the alarm primary power must be building wiring with battery backup, per CRC interconnection/power rules — see § R311.5 and § R311.6.
Numbers applied: 3 required alarms (one outside sleeping area upstairs, one on the main floor, one in basement/near furnace if basement/utility is an occupiable level), all UL 2075 listed or part of an NFPA 72 system — satisfy § R311.7.1 and § R311.7.2.
Related provisions (CRC sections)
- § R311.3 — Location of carbon monoxide alarms (specific residential locations such as outside sleeping areas and on every occupiable level).
- § R311.1.1 — Listing requirements for carbon monoxide alarms (UL 2034 for alarms; combination device listings) — see this for alarm/listing interplay.
- § R311.1.2 — Installation in accordance with listing and manufacturer instructions.
- § R311.5 — Interconnectivity requirements when multiple CO alarms are required in a dwelling unit.
- § R311.6 — Power source requirements for carbon monoxide alarms.
- § R311.7.4 — Combination CO/smoke detectors used in CO detection systems must meet UL 268 and UL 2075 and Office of the State Fire Marshal requirements.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 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.
CRC § 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:
- 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.
- Water-resistive barriers installed in accordance with Section 1402.6 of the California Building Code .
CRC § 7.1 High relevance — show source text
_
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.
R312.3 Height effect on room area. Portions of a room with a sloping ceiling measuring less than 5 feet (1524 mm) or a furred ceiling measuring less than 7 feet (2134 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required habitable area for that room.
SECTION R313—CEILING HEIGHT
R313.1 Minimum height. Habitable space, hallways and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).
Exceptions:
- For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 7 feet (2134 mm).
- The ceiling height above bathroom and toilet room fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a ceiling height of not less than 6 feet 8 inches (2032 mm) above an area of not less than 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.
- Beams, girders, ducts or other obstructions in basements containing habitable space shall be permitted to project to within 6 feet 4 inches (1931 mm) of the finished floor.
- Beams and girders spaced apart not less than 36 inches (914 mm) in clear finished width shall project not more than 78 inches (1981 mm) from the finished floor.
CRC § 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:
- 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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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.
CRC § 18001.8. High relevance — show source text
and the exclusive remedy for the_ failure to comply with this section is an award of actual damages not to exceed one hundred dollars ($100), exclusive of any court costs and attorney’s fees. h. Local ordinances requiring smoke detectors in single-family dwellings may be enacted or amended. However, the ordi- nances shall satisfy the minimum requirements of this section. i. For the purposes of this section, “single-family dwelling” does not include a manufactured home as defined in Section 18007, a mobilehome as defined in Section 18008, or a commercial coach as defined in Section 18001.8.
j. This section shall not apply to the installation of smoke detectors in dwellings intended for human occupancy, as defined in and regulated by Section 13113.7 of the Health and Safety Code, as added by Senate Bill No. 1448 in the 1983-84 Regular Session.
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SECTION R311—CARBON MONOXIDE ALARMS
R311.1 General. Ca rbon monoxide alarms shall comply with Section R311.
R311.1.1 Listings. Carbon monoxide alarms shall be listed and labeled in accordance with UL 2034. Combination carbon monoxide and smoke alarms shall be listed and labeled in accordance with UL 217 and 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.
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.
- The dwelling unit contains a fuel-fired appliance or fireplace.
- 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:
- 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.
- Installation, alteration or repairs of plumbing systems.
- Installation, alteration or repairs of mechanical systems that are not fuel fired.
CRC § 3-33 High relevance — show source text
R304 Protection of Wood and Wood-Based Products
Against Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
R305 Protection Against Subterranean Termites. . . . . . . 3-35
R306 Flood-Resistant Construction. . . . . . . . . . . . . . . . . . . 3-36
R307 Storm Shelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R308 Site Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R309 Automatic Sprinkler Systems . . . . . . . . . . . . . . . . . . . 3-41
R310 Smoke Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54
R311 Carbon Monoxide Alarms. . . . . . . . . . . . . . . . . . . . . . . 3-58
R312 Minimum Room Areas . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
R313 Ceiling Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
R314 Mezzanines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60
R315 Sleeping Lofts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60
R316 Habitable Attics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-61
R317 Garages and Carports. . . . . . . . . . . . . . . . . . . . . . . . . . 3-61
R318 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62
R319 Emergency Escape and Rescue Openings . . . . . . . . 3-65
R320 Handrails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67
R321 Guards and Window Fall Protection . . . . . . . . . . . . . 3-67
R322 Accessibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-68
R323 Elevators and Platform Lifts . . . . . . . . . . . . . . . . . . . . 3-68
R324 Glazing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-68
CRC § 2-5 High relevance — show source text
Part II—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
CHAPTER 2 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
R201 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
R202 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Part III—Building Planning and Construction . . . . . . . . . . . .3-5
CHAPTER 3 BUILDING PLANNING . . . . . . . . . . . . . . . . . . . . .3-5
R300 Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R301 Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
R302 Fire-Resistant Construction . . . . . . . . . . . . . . . . . . . . 3-23
R303 Foam Plastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
R304 Protection of Wood and Wood-Based Products
Against Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
R305 Protection Against Subterranean Termites. . . . . . . 3-35
R306 Flood-Resistant Construction. . . . . . . . . . . . . . . . . . . 3-36
R307 Storm Shelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R308 Site Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
R309 Automatic Sprinkler Systems . . . . . . . . . . . . . . . . . . . 3-41
R310 Smoke Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54
R311 Carbon Monoxide Alarms. . . . . . . . . . . . . . . . . . . . . . . 3-58
R312 Minimum Room Areas . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
R313 Ceiling Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59
CRC § 11-12 High relevance — show source text
(9) Transfers under the provisions of Chapter 7 (commencing with Section 3691) or Chapter 8 (commencing with Section 3771) of Part 6 of Division 1 of the Revenue and Taxation Code.
(e) No liability shall arise, nor any action be brought or maintained against any agent of any party to a transfer of title, including any person or entity acting in the capacity of an escrow, for any error, inaccuracy or omission relating to the disclosure required to be made by a transferor pursuant to this section.
However, this subdivision does not apply to a licensee, as defined in Section 10011 of the Business and Professions Code, where the licensee participates in the making of the disclosure required to be made pursuant to this section with actual knowl- edge of the falsity of the disclosure.
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(f) Except as otherwise provided in this section, this section shall not be deemed to create or imply a duty upon a licensee, as defined in Section 10011 of the Business and Professions Code, or upon any agent of any party to a transfer of title, including any person or entity acting in the capacity of an escrow, to monitor or ensure compliance with this section.
(g) No transfer of title shall be invalidated on the basis of a failure to comply with this section, and the exclusive remedy for the failure to comply with this section is an award of actual damages not to exceed one hundred dollars ($100), exclusive of any court costs and attorney’s fees.
(h) Local ordinances requiring smoke detectors in single-family dwellings may be enacted or amended. However, the ordinances shall satisfy the minimum requirements of this section.
(i) For the purposes of this section, “single-family dwelling” does not include a manufactured home as defined in Section 18007, a mobilehome as defined in Section 18008, or a commercial coach as defined in Section 18001.8.
(j) This section shall not apply to the installation of smoke detectors in dwellings intended for human occupancy, as defined in and regulated by Section 13113.7 of the Health and Safety Code, as added by Senate Bill No. 1448 in the 1983-84 Regular Session.
1103.9 Carbon monoxide detection. Carbon monoxide detection shall be installed in existing buildings where any of the conditions identified in Section 915.1.1 exist. Carbon monoxide alarms shall be installed in the locations specified in Section 915.2 and the installation shall be in accordance with Section 915.4.
Exceptions:
- Carbon monoxide alarms are permitted to be solely battery operated where the code that was in effect at the time of construction did not require carbon monoxide detectors to be provided.
- Carbon monoxide alarms are permitted to be solely battery operated in dwelling units that are not served from a commercial power source.
- A carbon monoxide detection system in accordance with Section 915.5 shall be an acceptable alternative to carbon monoxide alarms.
1103.9.1 Carbon monoxide detection in existing Group E buildings. For the purposes of carbon monoxide detection, an existing Group E is a building constructed before January 1, 2017. When an existing Group E occupancy has a fossil-fuel-burning furnace located inside the building, the school is encouraged to install carbon monoxide detection in accordance with the California Existing Building Code.
CRC § 5.2 High relevance — show source text
Defined R202 Dwelling-garage wall and ceiling penetration R302.5.2 System, definition R202 Dwelling Unit Separation R302.2, R302.3 Sprinklers (see Automatic Sprinkler System)
Electric Vehicle Charging Stations R317.6 Elevator R323.1, R323.3 Emergency Escape and Rescue Openings R319
Additions R319.6
Area wells R319.4 Bars, grilles, covers and screens R319.4.4
Basements, existing R319.7 Dimensions R319.2
Doors R319.3
Replacement window R319.5 Under decks and porches R319.2.4 Where required R319.1 Window fall protection R321.2 Emergency Housing Appendix CJ Energy Storage Systems R328 ESS vehicle impact protection Figure R330.8.1 Maximum aggregate ratings of ESS Table R330.5 Protection from impact R330.8 Toxic and highly toxic gas R330.12 Entry 1.8.5, R104.4 Existing Buildings Appendix BO Administrative R101.2, R102.6, R105.1, R105.8, R106.2, R113.1, R113.2 Basements R313.1.2, R319.7 Carbon monoxide alarms R311.2.2, R311.5, R311.6 Flood R104.3.1
Smoke alarms R310.2.2, R310.6 Stairways R318.7.9 Windows, replacement R319.5 Exterior Balconies and elevated walking surfaces R106.1.6
Covering R703 Insulation finish systems R703.9 Lath R703.7.1
Plaster R703.7 Exterior Insulation and Finish Systems (EIFS) 703.9
Exterior Wall
Construction R302.1
Fire-resistance rating R302.1
Factory Built Chimneys R1005 Fireplace stoves R1005.3 Fireplaces R1004 Fastening Table R602.3(1) Fees, Permit R108 Finishes Flame spread and smoke density R302.9 For ceilings R805 Interior R302.9, R311, R702 Fire Sprinkler System (see Automatic Sprinkler System) Ceiling configurations R309.3.4.1.1, R309.3.4.1.2, R309.3.4.1.3 Flow rate R309.3.4.1 Fireblocking Barrier between stories R302.11,
R602.8 Chimney R1003.19 Fireplace R1001.12 Fireplaces Chapter 10 Clearance R1001.11 Corbeling R1001.8 Factory-built R1004 Fireblocking R1001.12 Walls R1001.5
Fire-Resistant Construction R302 Draftstopping R302.2 Dwelling-garage fire separation R302.6 Dwelling-garage opening and penetration R302.5 Exterior walls R302.1 Fireblocking R302.11 Floors R302.13
Foam plastics R302.8 Insulation R302.10, R302.14 Penetrations R302.4
CRC § 18001.8. High relevance — show source text
7. Transfers between spouses resulting from a decree of dissolution of a marriage, from a decree of legal separation or from a property settlement agreement incidental to either of those decrees. 8. Transfers by the Controller in the course of administering the Unclaimed Property Law provided for in Chapter 7 (commencing with Section 1500) of Title 10 of Part 3 of the Code of Civil Procedure. 9. Transfers under the provisions of Chapter 7 (commencing with Section 3691) or Chapter 8 (commencing with Section 3771) of Part 6 of Division 1 of the Revenue and Taxation Code. e. No liability shall arise, nor any action be brought or maintained against, any agent of any party to a transfer of title, includ- ing any person or entity acting in the capacity of an escrow, for any error, inaccuracy or omission relating to the disclosure required to be made by a transferor pursuant to this section. However, this subdivision does not apply to a licensee, as defined in Section 10011 of the Business and Professions Code, where the licensee participates in the making of the disclo- sure required to be made pursuant to this section with actual knowledge of the falsity of the disclosure. f. Except as otherwise provided in this section, this section shall not be deemed to create or imply a duty upon a licensee, as defined in Section 10011 of the Business and Professions Code, or upon any agent of any party to a transfer of title, including any person or entity acting in the capacity of an escrow, to monitor or ensure compliance with this section. g. No transfer of title shall be invalidated on the basis of a failure to comply with this section, and the exclusive remedy for the failure to comply with this section is an award of actual damages not to exceed one hundred dollars ($100), exclusive of any court costs and attorney’s fees. h. Local ordinances requiring smoke detectors in single-family dwellings may be enacted or amended. However, the ordi- nances shall satisfy the minimum requirements of this section. i. For the purposes of this section, “single-family dwelling” does not include a manufactured home as defined in Section 18007, a mobilehome as defined in Section 18008, or a commercial coach as defined in Section 18001.8.
j. This section shall not apply to the installation of smoke detectors in dwellings intended for human occupancy, as defined in and regulated by Section 13113.7 of the Health and Safety Code, as added by Senate Bill No. 1448 in the 1983-84 Regular Session.
2025 CALIFORNIA RESIDENTIAL CODE 3-57
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
BUILDING PLANNING
SECTION R311—CARBON MONOXIDE ALARMS
R311.1 General. Ca rbon monoxide alarms shall comply with Section R311.
R311.1.1 Listings. Carbon monoxide alarms shall be listed and labeled in accordance with UL 2034. Combination carbon monoxide and smoke alarms shall be listed and labeled in accordance with UL 217 and 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.
CRC § 904.2 High relevance — show source text
(c) The owner or occupant shall promptly correct or repair deficiencies, damaged parts or impairments found while performing the inspection, test and maintenance requirements of this standard. Recalled products shall be replaced or remedied. Such replacement or remedial product shall be installed in accordance with the listing requirements, the manufacturer’s instructions and the appropri- ate NFPA installation standards. A recalled product is a product subject to a statute or administrative regulation specifically requiring the manufacturer, importer, distributor, wholesaler or retailer of a product, or any combination of such entities, to recall the product, or a product voluntarily recalled by a combination of such entities.
[California Code of Regulations, Title 19, Division 1, §904.2(d)] Testing and Maintenance Requirements.
(d) The building or system owner shall ensure immediate correction of any deficiencies noted during the service. A tag or label shall be affixed to a system only after all deficiencies have been corrected. The owner or occupant shall promptly correct or repair deficien- cies, damaged parts or impairments found while performing the inspection, test and maintenance requirements of this standard. Recalled products shall be replaced or remedied. Such replacement or remedial product shall be installed in accordance with the list- ing requirements, the manufacturer’s instructions and the appropriate NFPA installation standards. A recalled product is a product subject to a statute or administrative regulation specifically requiring the manufacturer, importer, distributor, wholesaler or retailer of a product, or any combination of such entities, to recall the product, or a product voluntarily recalled by a combination of such entities.
[California Code of Regulations, Title 19, Division 1, §904.2(e)] Testing and Maintenance Requirements.
(e) At the time of testing and maintenance, or at any time parts are replaced, an itemized invoice showing work performed and parts replaced shall be provided by the licensee to the system owner. If testing and maintenance is performed more than thirty (30) days prior to the next required testing and maintenance date, the invoice shall bear a statement indicating the system was tested and maintained early.
[California Code of Regulations, Title 19, Division 1, §904.2(f)] Testing and Maintenance Requirements.
(f) The licensee shall offer to return all replaced parts to the system owner or owner’s representative, except those parts that are required to be returned to the manufacturer under conditions of warranty.
901.7.1 Impairment coordinator. The building owner shall assign an impairment coordinator to comply with the requirements of this section. In the absence of a specific designee, the owner shall be considered to be the impairment coordinator.
901.7.2 Tag required. A tag shall be used to indicate that a system, or portion thereof, has been removed from service.
901.7.3 Placement of tag. The tag shall be posted at each fire department connection, system control valve, fire alarm control unit, fire alarm annunciator and fire command center, indicating which system, or part thereof, has been removed from service. The fire code official shall specify where the tag is to be placed.
9-10 2025 CALIFORNIA FIRE CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
FIRE PROTECTION AND LIFE SAFETY SYSTEMS
CRC § 915.5.1 High relevance — show source text
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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.
915.6.1 Enclosed parking garages. Carbon monoxide and nitrogen dioxide detectors installed in enclosed parking garages in accordance 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 720.
SECTION 916—GAS DETECTION SYSTEMS
916.1 Gas detection systems. Gas detection systems required by this code shall comply with Sections 916.2 through 916.11.
916.2 Permits. Permits shall be required as set forth in Section 105.6.11.
916.2.1 Construction documents. Documentation of the gas detection system design and equipment to be used that demonstrates compliance with the requirements of this code shall be provided with the application for permit.
916.3 Equipment. Gas detection system equipment shall be designed for use with the gases being detected and shall be installed in accordance with manufacturer’s instructions.
916.4 Power connections. Gas detection systems shall be permanently connected to the building electrical power supply or shall be permitted to be cord connected to an unswitched receptacle using an approved restraining means that secures the plug to the receptacle.
916.5 Emergency and standby power. Standby or emergency power shall be provided or the gas detection system shall initiate a trouble signal at an approved location if the power supply is interrupted.
916.6 Sensor locations. Sensors shall be installed in approved locations where leaking gases are expected to accumulate.
Frequently asked questions
Do carbon monoxide detection systems have to follow NFPA 72?
Yes. The CRC explicitly requires household carbon monoxide detection systems to comply with NFPA 72 — § R311.7.1.
What listing standard is required for standalone CO detectors?
Standalone carbon monoxide detectors must be listed to UL 2075 per § R311.7.1.
Can I use a combination CO + smoke alarm?
Yes — combination devices are permitted, but when used in a CO detection system they must be listed to UL 268 and UL 2075 and comply with State Fire Marshal requirements for smoke alarms (see § R311.7.4).
Where does the CRC require CO alarms to be placed?
The CRC requires CO detectors to be installed and maintained in the locations specified in Section R311.3 (for residences) or NFPA 72 when a detection system is used — § R311.7.2.
Must CO alarms be interconnected?
When more than one CO alarm is required in a dwelling unit, the alarms must be interconnected so that actuation of one alarm activates all (with limited exceptions for older existing buildings) — see § R311.5.
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