CRC · California Residential Code
Where must smoke alarms and carbon monoxide alarms be located and installed?
Homeowners: put a smoke alarm in every bedroom, one just outside the bedrooms, and at least one on every floor (including basements). Put CO alarms outside sleeping areas and on every occupiable level (and inside a bedroom if there’s a fuel‑burning appliance there). Use listed devices, follow manufacturer instructions, and interconnect multiple required alarms unless an existing‑building exception applies (see § R310 and § R311).
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
Smoke alarms are required in specified locations inside dwelling units — in each sleeping room, outside each sleeping area, and on each additional story (including basements) — per § R310.3. Carbon monoxide (CO) alarms are required outside each separate sleeping area and on every occupiable level, and additionally inside a bedroom if a fuel‑burning appliance is located in that bedroom — per § R311.3. Both types of alarms must be installed and listed per their listings and manufacturers’ instructions (see § R310.1.2 and § R311.1.2).
The single most important requirement: install smoke alarms in every sleeping room and immediately outside sleeping areas, and install CO alarms outside sleeping areas and on every occupiable level.
Requirements in detail
What to install (listing & type)
- Alarms must be listed and labeled: smoke alarms per UL 217 and CO alarms per UL 2034; combination units must meet both listings where applicable — § R310.1.1 and § R311.1.1. Install per the device listing and the manufacturer’s instructions — § R310.1.2 and § R311.1.2.
Where to place smoke alarms (high-level)
- In each sleeping room. Outside each separate sleeping area in the immediate vicinity of the bedrooms. On each additional story, including basements and habitable attics (crawl/uninhabitable attics excluded) — § R310.3.
Where to place carbon monoxide alarms (high-level)
- Outside each separate sleeping area in the immediate vicinity of the bedrooms.
- On every occupiable level of the dwelling unit, including basements.
- Inside a bedroom if a fuel‑burning appliance is located in that bedroom (or attached bathroom) — § R311.3.
Interconnection and power
- Where more than one smoke alarm or CO alarm is required in a dwelling unit, they must be interconnected so that activation of one alarm activates all alarms in the unit (physical interconnect or listed wireless) — § R310.4 and § R311.5. Exceptions for existing buildings are provided — see the code text for conditions where interconnection is not required.
- CO alarms must receive primary power from building wiring where commercial power is provided and have battery backup; limited exceptions allow battery‑only in buildings without commercial power or certain existing building conditions — § R311.6.
Specific location restrictions and clearances (decision‑relevant dimensions)
The NFPA requirements adopted by reference set placement exclusions and clearances for smoke alarms. Key distances and limits you must consider:
| Decision factor | Requirement / value | Code Reference |
|---|---|---|
| Required locations (sleeping rooms, outside sleeping areas, each story) | See list of required locations | § R310.3 |
| Distance from bathroom door (tub/shower) | Not less than 3 ft (914 mm) horizontally from bathroom door/opening unless it prevents required placement | § R310.3.3(5) as referenced in § R310.3 |
| Exclusion zone around cooking appliance | 10 ft (3.0 m) radial exclusion along a horizontal flow path (unless listed for close proximity); photoelectric or listed units permitted closer under conditions | NFPA extract adopted by reference (see § R310.3.3) |
| Alternative cooking proximity distances | Photoelectric permitted > 6 ft (1.8 m) or listed units between 10–20 ft (3.0–6.1 m) with nuisance‑resistance or silencing | NFPA extract adopted by reference, cited from § R310.3.3 |
| Distance from HVAC supply registers or ceiling fan blades | Not within 36 in. (910 mm) horizontal path of supply registers or fan blade tip; avoid direct airflow | NFPA extract adopted by reference (see § R310.3.3) |
| Tray/coffered ceilings | Install on highest portion or on sloped portion within 12 in. (300 mm) vertically down from highest point | NFPA extract adopted by reference (see § R310.3.3) |
| Stairs / basements | For stairways to other occupied levels, place alarm so rising smoke can reach it; for stairways up from basement, install on basement ceiling near stair entry | NFPA extract / § R310.3.3 |
(These detailed placement items are adopted from NFPA 72 and are referenced in § R310.3.3 — consult the manufacturer’s installation instructions that accompany the listed alarm for mounting‑height, surface limits, and exact placement.)
Exceptions & special cases
- Combination smoke/CO alarms are allowed in place of separate units if they meet the required listings — § R310.5 and § R311.4.
- Interconnection is not required in certain existing buildings where no construction or limited repairs are made or where access for wiring would require removing finished surfaces; see the exceptions under § R310.4 and § R311.5 for the full list of conditions.
- CO alarms may be battery‑powered where there is no commercial power, and limited battery exceptions apply for alarms installed per § R311.2.2 or in existing buildings under specified conditions — see § R311.6.
- When a fuel‑burning appliance or fireplace is added by alteration, new CO alarms must be installed to meet § R311 requirements (see § R311.2.2).
If a placement rule conflicts with the ability to meet a required location, the code allows listed alarms for close‑proximity locations (for example, near kitchens) or alternate device types (photoelectric) per the NFPA extracts adopted by reference — see § R310.3.3.
Common mistakes
- Assuming a single alarm covers all stories: the code requires alarms on every occupiable level (CO) and additional story alarms (smoke) — § R311.3 and § R310.3.
- Installing alarms too close to cooking appliances or in direct airflow from HVAC registers or ceiling fans — heed the 10 ft / 6 ft / 36 in. distances in the NFPA guidance adopted in § R310.3.3.
- Not interconnecting required alarms (or using non‑listed wireless devices that do not meet the listing) — see § R310.4 and § R311.5.
- Ignoring manufacturer instructions and listing requirements — both smoke and CO alarms must be installed per their listings and instructions — § R310.1.2 and § R311.1.2.
Worked example — a concrete scenario
Scenario: 2‑story single‑family dwelling with a basement, three upstairs bedrooms (a single sleeping area), a gas furnace in an equipment closet on the main level, and an attached garage.
Apply the code:
Smoke alarms (per § R310.3):
- In each sleeping room: 3 smoke alarms (one per bedroom).
- Outside the sleeping area in the immediate vicinity of the bedrooms: 1 (hallway just outside the bedrooms).
- On each additional story (including basement and main level): the hallway alarm serves the upstairs story; you still need at least 1 alarm on the main floor (e.g., living room) and 1 in the basement near the stairs — so total smoke alarms = 3 (bedrooms) + 1 (upstairs hallway) + 1 (main) + 1 (basement) = 6. Note: if layout connects levels without intervening doors and meets the split‑level rules, some alarms may cover adjacent levels per the code exception — check § R310.3 for split‑level details.
Carbon monoxide alarms (per § R311.3):
- Because the dwelling contains a fuel‑fired appliance (gas furnace) and has an attached garage, CO alarms are required. Place 1 outside the sleeping area (hallway) and 1 on every occupiable level (main floor, upstairs, basement). If the upstairs hallway CO alarm is the one outside the sleeping area, it can satisfy both requirements for that level. Minimum CO alarms in this layout: 3 (one per occupiable level), with at least one located outside the bedrooms — § R311.2.1 and § R311.3.
Interconnection & power: Because multiple smoke and CO alarms are required in the dwelling, they must be interconnected so one alarm actuates all — § R310.4 and § R311.5 — and CO alarms should be wired with battery backup where commercial power is present unless an exception applies (§ R311.6).
Related provisions
- § R310.1.1 — Listings for smoke alarms (UL 217) and combination units.
- § R310.1.2 — Installation per listing and manufacturer instructions.
- § R310.4 — Interconnection requirements for smoke alarms.
- § R310.3.3 — Specific NFPA 72 location requirements (cooking proximity, HVAC, fans, ceilings).
- § R311.1.1 / § R311.1.2 — Listings and installation instructions for CO alarms.
- § R311.2.1 / § R311.2.2 — Where CO alarms are required for new and existing construction and where additions/alterations trigger new CO alarm installation.
- § R311.5 / § R311.6 — CO alarm interconnectivity and power source requirements.
(When planning installations, always confirm device mounting heights, surface limits and manufacturer‑supplied guidance — the code requires following the listing and instructions. See § R310.1.2 and § R311.1.2.)
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 29.8.3.4 High relevance — show source text
This extract has been provided by NFPA as amended by the Office of the State Fire Marshal and adopted by reference as follows:
NFPA 72 29.8.3.4 Specific location requirements. The installation of smoke alarms and smoke detectors shall comply with the following requirements: (1) Smoke alarms and smoke detectors shall not be located where ambient conditions, including humidity and temperature, are outside the limits specified by the manufacturer's published instructions. (2) Smoke alarms and smoke detectors shall not be located within unfinished attics or garages or in other spaces where tempera- tures can fall below 40ºF (4ºC) or exceed 100ºF (38ºC). (3) Where the mounting surface could become considerably warmer or cooler than the room, such as a poorly insulated ceiling below an unfinished attic or an exterior wall, smoke alarms and smoke detectors shall be mounted on an inside wall.
(4) Smoke alarms or smoke detectors shall be installed a minimum of 20 feet horizontal distance from a permanently installed cooking appliance. Exception: Ionization smoke alarms with an alarm-silencing switch or Photoelectric smoke alarms shall be permitted to be installed 10 feet (3 m) or greater from a permanently installed cooking appliance. Photoelectric smoke alarms shall be permitted to be installed greater than 6 feet (1.8 m) from a permanently installed cook- ing appliance where the kitchen or cooking area and adjacent spaces have no clear interior partitions and the 10 ft distances
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would prohibit the placement of a smoke alarm or smoke detector required by other sections of the code. Smoke alarms listed for use in close proximity to a permanently installed cooking appliance. (5) Installation near bathrooms. Smoke alarms shall be installed not less than a 3 foot (0.91 m) horizontal distance from the door or opening of a bathroom that contains a bathtub or shower unless this would prevent placement of a smoke alarm required by other sections of the code.
(6) Smoke alarms and smoke detectors shall not be installed within a 36 in. (910 mm) horizontal path from the supply registers of a forced air heating or cooling system and shall be installed outside of the direct airflow from those registers. (7) Smoke alarms and smoke detectors shall not be installed within a 36 in. (910 mm) horizontal path from the tip of the blade of a ceiling-suspended (paddle) fan. (8) Where stairs lead to other occupied levels, a smoke alarm or smoke detector shall be located so that smoke rising in the stair- way cannot be prevented from reaching the smoke alarm or smoke detector by an intervening door or obstruction. (9) For stairways leading up from a basement, smoke alarms or smoke detectors shall be located on the basement ceiling near the entry to the stairs. (10) For tray-shaped ceilings (coffered ceilings), smoke alarms and smoke detectors shall be installed on the highest portion of the ceiling or on the sloped portion of the ceiling within 12 in. (300 mm) vertically down from the highest point. (11) Smoke alarms and detectors installed in rooms with joists or beams shall comply with the requirements of 17.7.3.2.4. (12) Heat alarms and detectors installed in rooms with joists or beams shall comply with the requirements of 17.6.3.
CRC § 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.
- 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.
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.
CRC § 0.91 High relevance — show source text
would prohibit the placement of a smoke alarm or smoke detector required by other sections of the code. Smoke alarms listed for use in close proximity to a permanently installed cooking appliance. (5) Installation near bathrooms. Smoke alarms shall be installed not less than a 3 foot (0.91 m) horizontal distance from the door or opening of a bathroom that contains a bathtub or shower unless this would prevent placement of a smoke alarm required by other sections of the code.
(6) Smoke alarms and smoke detectors shall not be installed within a 36 in. (910 mm) horizontal path from the supply registers of a forced air heating or cooling system and shall be installed outside of the direct airflow from those registers. (7) Smoke alarms and smoke detectors shall not be installed within a 36 in. (910 mm) horizontal path from the tip of the blade of a ceiling-suspended (paddle) fan. (8) Where stairs lead to other occupied levels, a smoke alarm or smoke detector shall be located so that smoke rising in the stair- way cannot be prevented from reaching the smoke alarm or smoke detector by an intervening door or obstruction. (9) For stairways leading up from a basement, smoke alarms or smoke detectors shall be located on the basement ceiling near the entry to the stairs. (10) For tray-shaped ceilings (coffered ceilings), smoke alarms and smoke detectors shall be installed on the highest portion of the ceiling or on the sloped portion of the ceiling within 12 in. (300 mm) vertically down from the highest point. (11) Smoke alarms and detectors installed in rooms with joists or beams shall comply with the requirements of 17.7.3.2.4. (12) Heat alarms and detectors installed in rooms with joists or beams shall comply with the requirements of 17.6.3.
R310.4 Interconnection. Where more than one smoke alarm is required to be installed within an individual dwelling or sleeping unit, the smoke alarms shall be interconnected in such a manner that the activation of one alarm will activate all of the alarms in the individ- ual unit. The alarm shall be clearly audible in all bedrooms over background noise levels with all intervening doors closed.
Exceptions: 1. Interconnection is not required in buildings that are not undergoing alterations, repairs or construction of any kind. 2. Smoke alarms in existing areas are not required to be interconnected where alterations or repairs do not result in the removal of interior wall or ceiling finishes exposing the structure, unless there is an attic, crawl space or basement available which could provide access for interconnection without the removal of interior finishes. 3. Smoke alarms are not required to be interconnected where 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. Smoke alarms are not required to be interconnected when work is limited to the installation, alteration or repairs of plumb- ing or mechanical systems or the installation, alteration or repair of electrical systems which do not result in the removal of interior wall or ceiling finishes exposing the structure.
R310.5 Combination alarms. Combination smoke and carbon monoxide alarms shall be permitted to be used in lieu of smoke alarms. Systems and components shall be California State Fire Marshal listed and approved in accordance with California Code of Regu- lations, Title 19, Division 1 for the purpose for which they are installed.
CRC § 2.2 High relevance — show source text
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.
2. No construction is taking place. 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. 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.
R311.6 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.
CRC § 3.8.2 High relevance — show source text
- The piping system is tested in accordance with the California Plumbing Code.
R309.3.8.2 Final inspection. The following items shall be verified upon completion of the system:
- Sprinklers are not painted, damaged or otherwise hindered from operation.
- Where a pump is required to provide water to the system, the pump starts automatically upon system water demand.
- Pressure-reducing valves, water softeners, water filters or other impairments to water flow that were not part of the original design have not been installed.
- The sign or valve tag required by Section R309.3.7 is installed and the owner’s manual for the system is present.
SECTION R310—SMOKE ALARMS
R310.1 General. Smoke alarms shall comply with NFPA 72, Section R310 and the manufacturer’s installation instructions.
R310.1.1 Listings. Smoke alarms shall be listed and labeled in accordance with UL 217. Combination smoke and carbon monoxide alarms shall be listed and labeled in accordance with UL 217 and UL 2034. Systems and components shall be California State Fire Marshal listed and approved in accordance with California Code of Regulations, Title 19, Division 1 for the purpose for which they are installed.
R310.1.2 Installation. Smoke alarms and combination smoke and carbon monoxide alarms shall be installed in accordance with their listing and the manufacturer’s instructions.
R310.2 Where required. Smoke alarms shall be provided in accordance with this section.
R310.2.1 New construction. Smoke alarms shall be provided in dwelling units.
R310.2.2 Alterations, repairs and additions. Where alterations, repairs or additions requiring a permit occur, the individual dwelling unit shall be equipped with smoke alarms located as required for new dwellings.
Exceptions: See Section R310.6.
R310.3 Location. Smoke alarms shall be installed in the following locations:
- In each sleeping room.
- Outside each separate sleeping area in the immediate vicinity of the bedrooms.
- On each additional story of the dwelling unit, including basements and habitable attics and not including crawl spaces and uninhabitable attics. In dwelling units with split levels and without an intervening door between the adjacent levels, a smoke alarm installed on the upper level shall suffice for the adjacent lower level provided that the lower level is less than one full story below the upper level.
- Not less than 3 feet (914 mm) horizontally from the door or opening of a bathroom that contains a bathtub or shower unless this would prevent placement of a smoke alarm required by this section.
- In the hallway and in the room open to the hallway in dwelling units where the ceiling height of a room open to a hallway serving bedrooms exceeds that of the hallway by 24 inches (610 mm) or more.
- Within the room to which a sleeping loft is open, in the immediate vicinity of the sleeping loft.
See Section R310.3.3 for specific location requirements.
R310.3.1 Installation near cooking appliances. See Section R310.3.3 for specific location requirements.
R310.3.2 Smoke alarms. Smoke alarms shall be tested and maintained in accordance with the manufacturer’s instructions. Smoke alarms that no longer function shall be replaced.
R310.3.3 Specific location requirements. Extract from NFPA 72 Section 29.8.3.4 Specific Location Requirements.*
CRC § 907.2.11.7 High relevance — show source text
[F] 907.2.11.7 Smoke detection system. Smoke detectors listed in accordance with UL 268 and provided as part of the building fire alarm system shall be an acceptable alternative to single- and multiple-station smoke alarms and shall comply with the following:
- The fire alarm system shall comply with all applicable requirements in Section 907.
- Activation of a smoke detector in a dwelling unit or sleeping unit shall initiate alarm notification in the dwelling unit or sleeping unit in accordance with Section 907.5.2.
- Activation of a smoke detector in a dwelling unit or sleeping unit shall not activate alarm notification appliances outside of the dwelling unit or sleeping unit, provided that a supervisory signal is generated and monitored in accordance with Section 907.6.6.
907.2.11.8 Specific location requirements.
Extract from NFPA 72 Section 29.11.3.4 Specific Location Requirements*.
This extract has been provided by NFPA for the Office of the State Fire Marshal adoption by reference as follows:
29.11.3.4 Specific location requirements. The installation of smoke alarms and smoke detectors shall comply with the following requirements: (1) Smoke alarms and smoke detectors shall not be located where ambient conditions, including humidity and temperature, are outside the limits specified by the manufacturer's published instructions. (2) Smoke alarms and smoke detectors shall not be located within unfinished attics or garages or in other spaces where temperatures can fall below 40ºF (4ºC) or exceed 100ºF (38ºC). (3) Where the mounting surface could become considerably warmer or cooler than the room, such as a poorly insulated ceil- ing below an unfinished attic or an exterior wall, smoke alarms and smoke detectors shall be mounted on an inside wall. (4) Smoke alarms and smoke detectors shall not be installed within an area of exclusion determined by a 10-foot (3.0 m) radial distance along a horizontal flow path from a stationary or fixed cooking appliance, unless listed for installation in close proximity to cooking appliances. Smoke alarms and smoke detectors installed between 10 feet (3.0 m) and 20 feet (6.1 m) along a horizontal flow path from a stationary or fixed appliance shall be equipped with an alarm-silencing means or use photoelectric detection.
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(5) Smoke alarms or smoke detectors that use photoelectric detection shall be permitted for installation at a radial distance greater than 6 feet (1.8 m) from any stationary or fixed cooking appliance when both of the following conditions are met: (a) The kitchen or cooking area and adjacent spaces have no clear partitions or headers. (b) The 10-foot (3.0 m) area of exclusion would prohibit the placement of a smoke alarm or smoke detector required by other sections of this code. (6) Effective January 1, 2022, smoke alarms and smoke detectors installed between 6 feet (1.8 m) and 20 feet (6.1 m) along a horizontal flow path from a stationary or fixed cooking appliance shall be listed for resistance to common nuisance sources from cooking. (7) Smoke alarms and smoke detectors shall not be installed within a 36-inch (910 mm) horizontal path from a door to a _bathroom containing a shower or tub unless listed for installation in close proximity to such locations.
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 § 907.2.11.6 High relevance — show source text
907.2.11.6 Power source. In new construction, and in newly classified Group R-3.1 occupancies, required smoke alarms shall receive their primary power from the building wiring where such wiring is served from a commercial source and shall be equipped with a battery backup. Smoke alarms with integral strobes that are not equipped with battery back-up shall be connected to an emergency electrical system in accordance with Section 1203. Smoke alarms shall emit a signal when the batteries are low. Wiring shall be permanent and without a disconnecting switch other than as required for overcurrent protection.
Exception: Smoke alarms are not required to be equipped with battery backup where they are connected to an emergency electrical system that complies with Section 603.
907.2.11.7 Smoke detection system. Smoke detectors listed in accordance with UL 268 and provided as part of the building fire alarm system shall be an acceptable alternative to single- and multiple-station smoke alarms and shall comply with the following:
- The fire alarm system shall comply with all applicable requirements in Section 907.
- Activation of a smoke detector in a dwelling unit or sleeping unit shall initiate alarm notification in the dwelling unit or sleeping unit in accordance with Section 907.5.2.
- Activation of a smoke detector in a dwelling unit or sleeping unit shall not activate alarm notification appliances outside of the dwelling unit or sleeping unit, provided that a supervisory signal is generated and monitored in accordance with Section 907.6.6.
907.2.11.8 Specific location requirements.
Extract from NFPA 72 Section 29.11.3.4 Specific Location Requirements*.
This extract has been provided by NFPA for the Office of the State Fire Marshal adoption by reference as follows:
29.11.3.4 Specific location requirements. The installation of smoke alarms and smoke detectors shall comply with the follow- ing requirements:
(1) Smoke alarms and smoke detectors shall not be located where ambient conditions, including humidity and temperature, are outside the limits specified by the manufacturer's published instructions.
(2) Smoke alarms and smoke detectors shall not be located within unfinished attics or garages or in other spaces where temperatures can fall below 40ºF (4ºC) or exceed 100ºF (38ºC).
(3) Where the mounting surface could become considerably warmer or cooler than the room, such as a poorly insulated ceil- ing below an unfinished attic or an exterior wall, smoke alarms and smoke detectors shall be mounted on an inside wall.
(4) Smoke alarms and smoke detectors shall not be installed within an area of exclusion determined by a 10-foot (3.0 m) radial distance along a horizontal flow path from a stationary or fixed cooking appliance, unless listed for installation in close proximity to cooking appliances. Smoke alarms and smoke detectors installed between 10 feet (3.0 m) and 20 feet (6.1 m) along a horizontal flow path from a stationary or fixed appliance shall be equipped with an alarm-silencing means or use photoelectric detection.
(5) Smoke alarms or smoke detectors that use photoelectric detection shall be permitted for installation at a radial distance greater than 6 feet (1.8 m) from any stationary or fixed cooking appliance when both of the following conditions are met: (a) The kitchen or cooking area and adjacent spaces have no clear partitions or headers.
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FIRE PROTECTION AND LIFE SAFETY SYSTEMS
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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PROVISIONS FOR ALL COMPLIANCE METHODS
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 § 3.8.1 High relevance — show source text
R309.3.8.1 Preconcealment inspection. The following items shall be verified prior to the concealment of any automatic sprinkler system piping:
- Sprinklers are installed in all areas as required by Section R309.3.1.1.
- Where sprinkler water spray patterns are obstructed by construction features, luminaires or ceiling fans, additional sprinklers are installed as required by Section R309.3.2.4.2.
- Sprinklers are the correct temperature rating and are installed at or beyond the required separation distances from heat sources as required by Sections R309.3.2.1 and R309.3.2.2 .
- The pipe size equals or exceeds the size used in applying Tables R309.3.6.2 (4) through R309.3.6.2 (9) or, if the piping system was hydraulically calculated in accordance with Section R309.3.6.1, the size used in the hydraulic calculation.
- The pipe length does not exceed the length permitted by Tables R309.3.6.2 (4) through R309.3.6.2 (9) or, if the piping system was hydraulically calculated in accordance with Section R309.3.6.1, pipe lengths and fittings do not exceed those used in the hydraulic calculation.
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BUILDING PLANNING
Nonmetallic piping that conveys water to sprinklers is listed for use with fire sprinklers.
Piping is supported in accordance with the pipe manufacturer’s and sprinkler manufacturer’s installation instructions.
The piping system is tested in accordance with the California Plumbing Code.
R309.3.8.2 Final inspection. The following items shall be verified upon completion of the system:
- Sprinklers are not painted, damaged or otherwise hindered from operation.
- Where a pump is required to provide water to the system, the pump starts automatically upon system water demand.
- Pressure-reducing valves, water softeners, water filters or other impairments to water flow that were not part of the original design have not been installed.
- The sign or valve tag required by Section R309.3.7 is installed and the owner’s manual for the system is present.
SECTION R310—SMOKE ALARMS
R310.1 General. Smoke alarms shall comply with NFPA 72, Section R310 and the manufacturer’s installation instructions.
R310.1.1 Listings. Smoke alarms shall be listed and labeled in accordance with UL 217. Combination smoke and carbon monoxide alarms shall be listed and labeled in accordance with UL 217 and UL 2034. Systems and components shall be California State Fire Marshal listed and approved in accordance with California Code of Regulations, Title 19, Division 1 for the purpose for which they are installed.
R310.1.2 Installation. Smoke alarms and combination smoke and carbon monoxide alarms shall be installed in accordance with their listing and the manufacturer’s instructions.
R310.2 Where required. Smoke alarms shall be provided in accordance with this section.
R310.2.1 New construction. Smoke alarms shall be provided in dwelling units.
CRC § 907.3.1 High relevance — show source text
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FIRE PROTECTION AND LIFE SAFETY SYSTEMS
normal electrical service and, upon actuation, perform the intended function. The detectors shall be located in accordance with NFPA 72.
907.3.1 Duct smoke detectors. Smoke detectors installed in ducts shall be listed for the air velocity, temperature and humidity present in the duct. Duct smoke detectors shall be connected to the building’s fire alarm control unit where a fire alarm system is required by Section 907.2. Activation of a duct smoke detector shall initiate a visible and audible supervisory signal at a constantly attended location and shall perform the intended fire safety function in accordance with this code and the California Mechanical Code . In facilities that are required to be monitored by a supervising station, duct smoke detectors shall report only as a supervisory signal and not as a fire alarm. They shall not be used as a substitute for required open area detection.
Exceptions:
- The supervisory signal at a constantly attended location is not required where duct smoke detectors activate the building’s alarm notification appliances.
- In occupancies not required to be equipped with a fire alarm system, actuation of a smoke detector shall activate a visible and an audible signal in an approved location. Smoke detector trouble conditions shall activate a visible or audible signal in an approved location and shall be identified as air duct detector trouble.
907.3.2 Special locking systems. Where special locking systems are installed on means of egress doors in accordance with Section 1010.2.13 or 1010.2.12, an automatic smoke detection system shall be installed as required by those sections and Sections 907.3.2.1 through 907.3.2.5.
907.3.2.1 Delayed egress. In other than Group I, Group R-2.1 and Group R-4, occupancies for single-story building smoke detectors shall be installed at ceilings throughout all occupied areas and mechanical/electrical spaces. For multiple-story buildings, smoke detectors shall be installed throughout all occupied areas and mechanical/electrical spaces for the story where delayed egress devices are installed. Additional detectors are required on adjacent stories where occupants of those stories utilize the same means of
egress.
Exception: Refer to Section 907.3.2.4 for Group A courthouse occupancies.
907.3.2.2 Delayed egress for Group I and R-2.1 occupancies. Smoke detectors shall be installed at ceilings throughout all occupied areas and mechanical/electrical spaces of smoke-compartments where delayed egress devices are installed. Additional detectors are required in adjacent smoke-compartments where occupants of those compartments utilize the same means of egress.
907.3.2.3 Delayed egress for Group R-4 occupancies. In occupancies licensed as residential care facilities for the elderly and housing clients with Alzheimer’s disease or dementia, smoke detectors shall be installed at ceilings throughout all occupiable rooms and areas and mechanical/electrical rooms and spaces.
907.3.2.4 Delayed egress for Group A Courthouse occupancies. Approved automatic smoke detection systems shall be installed at ceilings in all occupied corridors and mechanical/electrical spaces of occupancies where delayed egress devices are installed.
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.
Frequently asked questions
Do combination smoke/CO alarms satisfy both § R310 and § R311 requirements?
Yes. Combination alarms are permitted in lieu of separate units provided they meet the required listings (UL 217 and UL 2034) and are installed per their listing and manufacturer instructions — see § R310.5 and § R311.4.
Are alarms required in existing homes that never had them?
CO alarms are required in existing dwelling units when the dwelling contains a fuel‑fired appliance or an attached garage that communicates with the dwelling — § R311.2.1. Smoke alarms are required when alterations, repairs or additions requiring a permit occur; see § R310.2.2 for alterations.
Must alarms be hard‑wired with battery backup?
CO alarms must receive primary power from building wiring where served from commercial power and have battery backup; exceptions allow battery‑only where no commercial power exists or in certain existing buildings — § R311.6. Smoke alarms in new construction are typically hard‑wired with battery backup per applicable provisions and the referenced NFPA/Fire Code requirements; check local code enforcement for power specifics.
Do alarms have to be interconnected?
Yes — where more than one required smoke or CO alarm is installed within a dwelling unit, they must be interconnected so activation of one triggers all — § R310.4 and § R311.5. Exceptions exist for many existing buildings under limited conditions.
How close can a smoke alarm be to a kitchen or bathroom?
Keep smoke alarms at least 3 ft (914 mm) from a bathroom door containing a tub or shower and respect the cooking appliance exclusion zone (generally 10 ft radial along horizontal flow paths; photoelectric or listed close‑proximity units can be used closer under conditions) — see the NFPA provisions adopted in § R310.3.3.
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