CRC · California Residential Code

What fire detection and alarm provisions apply when ESS are installed in dwellings?

If you install an energy storage system (ESS) inside your home—such as in a garage, basement, or other room—the California Residential Code requires that the area be protected by smoke alarms; if a smoke alarm cannot be installed in that specific location because of its listing, you must install a listed heat detector that is interconnected to the home’s smoke alarms (see § R330.7).

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

When an energy storage system (ESS) is installed inside a dwelling, the dwelling rooms and areas where the ESS is located must be protected by smoke alarms and, where smoke alarms cannot be installed per their listing, a listed heat detector that is interconnected to the smoke alarms must be provided. The controlling California Residential Code provision is § R330.7.

The single most important rule: protect every room or area in the dwelling that contains an ESS with smoke alarms, and where smoke alarms cannot be installed per their listing, provide a listed, interconnected heat detector. § R330.7.

Requirements in detail

Scope and where the detection is required

  • Locations specifically named: rooms and areas within dwelling units, basements, and attached garages that contain ESS. See § R330.7.
  • State Fire Marshal (SFM) note: for Group R-3 and townhomes the CRC reiterates the requirement and points to Section R314 for smoke-alarm specifics; heat alarms likewise where smoke alarms cannot be installed. § R330.7 (SFM text).

What type of detector is required

  • Primary: smoke alarms in accordance with Section R310 (or R314 for R-3/townhomes as noted). § R330.7.
  • Alternate where smoke alarms cannot be installed based on their listing: a listed heat detector/heat alarm that is interconnected to the smoke alarms. § R330.7.

Interconnection

  • The code requires the heat detector to be interconnected to the smoke alarms so activation of the heat alarm will also activate the dwelling smoke alarms. § R330.7.

Decision‑relevant dimensions / values (quick reference table)

Decision dimension Value / requirement Code Reference
Required device in ESS-containing dwelling areas Smoke alarms (primary); listed heat detector where smoke alarms cannot be installed per listing § R330.7
Interconnection Heat detector must be listed and interconnected to the smoke alarms § R330.7
Where to apply Rooms/areas within dwelling units, basements, attached garages § R330.7
Individual ESS unit maximum rating (context for applicability) 20 kWh (individual unit limit under R330.5) § R330.5
Total aggregate on property (context) 600 kWh (aggregate cap; above that, follow CFC §1207) § R330.5
If ESS installation exceeds CRC limits Install per California Fire Code Section 1207 (more extensive detection & suppression requirements) § R330.5 and CFC § 1207

Notes on referenced alarm standards

  • R330.7 points to the smoke‑alarm installation requirements in the residential code (Section R310 or R314 for SFM text). The CRC text requires compliance with those sections for the type, placement and power source of smoke alarms. § R330.7.

Exceptions & special cases

  • Small ESS exemption: ESS less than 1 kWh are an installation exception in R330.1; if that exception applies the ESS-specific detection rule in R330.7 may not be triggered. § R330.1.
  • Larger or non‑residential‑scale ESS: where installed capacity or location exceed the CRC limits (see § R330.5), installations must follow the California Fire Code (CFC) requirements (Section 1207), which include more prescriptive automatic detection and transmission requirements. § R330.5 and CFC § 1207.5.4.
  • SFM wording: For Group R-3 and townhomes, CRC text points specifically to Section R314 for the smoke alarm standard and requires a listed heat alarm where smoke alarms cannot be installed (SFM note inside § R330.7).

If a specific scenario or technology isn’t addressed in the CRC excerpts available here (for example, special listing conditions of an ESS product or non‑electrochemical technologies), the CFC’s Section 1207 and product listings / manufacturer instructions are the next authoritative references; those CFC provisions are available and were considered for related requirements.

Common mistakes

  • Assuming any detector qualifies: installing a non‑listed heat detector or a heat detector that is not interconnected is noncompliant. The code requires a listed heat detector that is interconnected to the smoke alarms. § R330.7.
  • Missing the location list: omitting protection in basements or attached garages that contain an ESS. R330.7 explicitly lists these locations. § R330.7.
  • Treating garage installations as “outside” and skipping detection: attached garages are inside the R330.7 scope and must be protected. § R330.7.
  • Relying only on general home smoke‑alarm spacing rules without checking the referenced residential sections (R310/R314) and the ESS-specific requirement to add a heat detector where smoke alarms are not permitted by their listing. § R330.7.
  • Ignoring aggregate/individual capacity limits: installing large-capacity ESS without moving to CFC §1207 requirements (which add more stringent detection and alarm obligations). § R330.5 and CFC § 1207.

Worked example — concrete scenario

Scenario: A homeowner installs a listed 10 kWh wall-mounted ESS inside an attached garage of a single‑family dwelling.

Step-by-step application of CRC provisions:

  1. Applicability: a 10 kWh unit is below the CRC individual unit cap of 20 kWh and the property aggregate is below 600 kWh, so CRC § R330 applies (not automatically escalated to CFC §1207). § R330.5.
  2. Detection requirement: because the ESS is in an attached garage, smoke alarms must protect the room/area in accordance with Section R310 (or R314 if Group R-3/townhome language applies). Install smoke alarms per the residential section. § R330.7.
  3. If the chosen smoke alarm model’s listing specifically prohibits installation in the garage location (for example, the alarm listing may limit use to living spaces), then the code allows a listed heat detector to be installed in that location, but it must be interconnected to the dwelling smoke alarms so that activation of the heat alarm notifies the whole unit. § R330.7.
  4. Verification: confirm detectors are listed, power/interconnection meet the residential sections’ requirements, and the ESS manufacturer listing and installation instructions are followed. If the installation exceeded CRC capacity limits or the ESS listing requires different protection, follow CFC §1207. § R330.5 and CFC § 1207.

Related provisions

  • § R330.1 — General ESS scope and exceptions (including the <1 kWh exception).
  • § R330.3 — ESS installation per manufacturer instructions and listing.
  • § R330.4 — Allowed locations; ESS shall not be installed in sleeping rooms (location limits relevant to detection application).
  • § R330.5 — Energy ratings: 20 kWh individual limit and 600 kWh aggregate limit (triggers for CFC).
  • § R330.8 — Protection from vehicle impact (garage installations). (Not detection, but often relevant in garage ESS siting.)
  • Section R310 / Section R314 — Residential smoke alarm installation standards referenced by § R330.7.
  • California Fire Code § 1207 (Energy Storage Systems) — additional detection and alarm requirements for larger or non‑residential ESS installations (see CFC §1207.5.4 and related).

Code references

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

  • CRC § 1207.1.5 High relevance — show source text

    A minimum of 1 foot vertically below the bottom edge of the ESS._
    3. A minimum of 8 feet vertically above the ESS, or to a non-combustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5 of the California Fire Code.|For SI: 1 foot = 304.8 mm.
    a. Noncombustible wall surface shall extend in accordance with all the following:
    1. A minimum of 5 feet horizontally from the edge of the ESS.
    2. A minimum of 1 foot vertically below the bottom edge of the ESS.
    3. A minimum of 8 feet vertically above the ESS, or to a non-combustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5 of the California Fire Code.|For SI: 1 foot = 304.8 mm.
    a. Noncombustible wall surface shall extend in accordance with all the following:
    1. A minimum of 5 feet horizontally from the edge of the ESS.
    2. A minimum of 1 foot vertically below the bottom edge of the ESS.
    3. A minimum of 8 feet vertically above the ESS, or to a non-combustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5 of the California Fire Code.|

    R330.6 Electrical installation. ESS shall be installed in accordance with the California Electrical Code. Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing. Systems connected to the utility grid shall use inverters listed for utility interaction.

    R330.7 Fire detection. Rooms and areas within dwelling units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R310. A heat detector, listed and interconnected to the smoke alarms, shall be installed in locations within dwelling units and attached garages where smoke alarms cannot be installed based on their listing.

    [SFM] ESS installed in Group R-3 and townhomes shall comply with the following: 1. Rooms and areas within dwellings units, sleeping units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R314. 2. A listed heat alarm interconnected to the smoke alarms shall be installed in locations within dwelling units, sleeping units and attached garages where smoke alarms cannot be installed based on their listing.

    R330.8 Protection from impact. ESS installed in a location subject to vehicle damage in accordance with Section R330.8.1 or R330.8.2 shall be provided with impact protection in accordance with Section R328.8.3.

    R330.8.1 Garages. Where an ESS is installed in the normal driving path of vehicle travel within a garage, impact protection complying with Section R330.8.3 shall be provided. The normal driving path is a space between the garage vehicle opening and the interior face of the back wall to a height of 48 inches (1219 mm) above the finished floor.

  • CRC § 1207.5.4 High relevance — show source text

    1. Where approved, installations shall be permitted in underground vaults complying with the California Electrical Code, Article 450, Part III.

    2. Where approved by the fire code official, installations shall be permitted on higher and lower floors. 1207.5.4 Fire detection. An approved automatic smoke detection system or radiant energy-sensing fire detection system complying with Section 907.2 shall be installed in rooms, indoor areas and walk-in units containing electrochemical ESS. An approved radiant energy-sensing fire detection system shall be installed to protect open parking garage and rooftop installations. Alarm signals from detection systems shall be transmitted to a central station, proprietary or remote station service in accordance with NFPA 72, or where approved to a constantly attended location. Exception: Normally unoccupied, remote stand-alone telecommunications structures with a gross floor area of less than 1,500 square feet (139 m [2] ) utilizing lead-acid or nickel-cadmium batteries shall not be required to have a fire detection system installed. (Material based on NFPA 855 2023 Ed.)

    1207.5.4.1 System status. Lead-acid and nickel-cadmium battery systems that are used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations, shall be allowed to use the process control system to monitor the smoke or radiant energy-sensing fire detectors required in Section 1207.5.4. (Material based on NFPA 855 2023 Ed.) 1207.5.5 Fire suppression systems. Rooms and areas within buildings and walk-in units containing electrochemical ESS shall be protected by an automatic fire suppression system designed and installed in accordance with one of the following:

    1. Automatic sprinkler systems designed and installed in accordance with Section 903.3.1.1 for ESS units (groups) with a maximum stored energy capacity of 50 kWh, as described in Section 1207.5.1, shall be designed with a minimum density of 0.3 gpm/ft [2] (1.14 L/min) based over the area of the room or 2,500 square-foot (232 m [2] ) design area, whichever is smaller, unless a lower density is approved based on large-scale fire testing in accordance with Section 1207.1.7.
    2. Automatic sprinkler systems designed and installed in accordance with Section 903.3.1.1 for ESS units (groups) exceeding 50 kWh shall use a density based on large-scale fire testing complying with Section 1207.1.7.
    3. The following alternative automatic fire-extinguishing systems designed and installed in accordance with Section 904, provided that the installation is approved by the fire code official based on large-scale fire testing complying with Section 1207.1.7:

    3.1. NFPA 12, Standard on Carbon Dioxide Extinguishing Systems . 3.2. NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection . 3.3. NFPA 750, Standard on Water Mist Fire Protection Systems . 3.4. NFPA 2001, Standard on Clean Agent Fire-Extinguishing Systems . 3.5. NFPA 2010, Standard for Fixed Aerosol Fire-Extinguishing Systems . Exceptions: 1.

  • CRC § 8.1 High relevance — show source text

    R330.7 Fire detection. Rooms and areas within dwelling units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R310. A heat detector, listed and interconnected to the smoke alarms, shall be installed in locations within dwelling units and attached garages where smoke alarms cannot be installed based on their listing.

    [SFM] ESS installed in Group R-3 and townhomes shall comply with the following: 1. Rooms and areas within dwellings units, sleeping units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R314. 2. A listed heat alarm interconnected to the smoke alarms shall be installed in locations within dwelling units, sleeping units and attached garages where smoke alarms cannot be installed based on their listing.

    R330.8 Protection from impact. ESS installed in a location subject to vehicle damage in accordance with Section R330.8.1 or R330.8.2 shall be provided with impact protection in accordance with Section R328.8.3.

    R330.8.1 Garages. Where an ESS is installed in the normal driving path of vehicle travel within a garage, impact protection complying with Section R330.8.3 shall be provided. The normal driving path is a space between the garage vehicle opening and the interior face of the back wall to a height of 48 inches (1219 mm) above the finished floor. The width of the normal driving path shall be equal to the width of the garage door opening. Impact protection shall also be provided for an ESS installed at either of the following locations (see Figure R330.8.1):

    1. On the interior face of the back wall and located within 36 inches (914 mm) to the left or to the right of the normal driving path.
    2. On the interior face of a side wall and located within 24 inches (610 mm) from the back wall and 36 inches (914 mm) of the normal driving path.

    Exception: Where the clear height of the vehicle garage opening is 7 feet 6 inches (2286 mm) or less, ESS installed not less than 36 inches (914 mm) above finished floor are not subject to vehicle impact protection requirements.

    2025 CALIFORNIA RESIDENTIAL CODE 3-77

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

    BUILDING PLANNING

    FIGURE R330.8.1—ESS VEHICLE IMPACT PROTECTION

    For SI: 1 inch = 25.4 mm.

    R330.8.2 Other locations subject to vehicle impact. Where an ESS is installed in a location other than as defined in Section R330.8.1 and is subject to vehicle damage, impact protection shall be provided in accordance with Section R330.8.3.

    R330.8.3 Impact protection options. ESS protection shall comply with one of the following:

    1. Bollards constructed in accordance with one of the following: 1.1. Minimum 48 inches (1219 mm) in length by 3 inches (76 mm) in diameter Schedule 80 steel pipe embedded in a concrete pier not less than 12 inches (305 mm) deep and 6 inches (152 mm) in diameter, with not less than 36 inches (914 mm) of pipe exposed, filled with concrete and spaced at a maximum interval of 5 feet (1524 mm).
  • CRC § 304.8 High relevance — show source text

    a_| |In detached garages and detached accessory structures|200|| |In detached garages and detached accessory structures|600|Detached garage or detached accessory structure is
    a minimum 10 feet away from property lines and
    dwellings.| |Outdoors on the ground|200|ESS is a minimum 3 feet away from property lines
    and dwellings.| |Outdoors on the ground|600|ESS is a minimum 10 feet away from property lines
    and dwellings.| |For SI: 1 foot = 304.8 mm
    a. Noncombustible wall surface shall extend in accordance with all the following:
    1. A minimum of 5 feet horizontally from the edge of the ESS.
    2. A minimum of 1 foot vertically below the bottom edge of the ESS.
    3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5.|For SI: 1 foot = 304.8 mm
    a. Noncombustible wall surface shall extend in accordance with all the following:
    1. A minimum of 5 feet horizontally from the edge of the ESS.
    2. A minimum of 1 foot vertically below the bottom edge of the ESS.
    3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5.|For SI: 1 foot = 304.8 mm
    a. Noncombustible wall surface shall extend in accordance with all the following:
    1. A minimum of 5 feet horizontally from the edge of the ESS.
    2. A minimum of 1 foot vertically below the bottom edge of the ESS.
    3. A minimum of 8 feet vertically above the ESS, or to a noncombustible eave, whichever is less.
    The code official is authorized to approve reductions of installation requirements based on large-scale fire testing complying with Section 1207.1.5.|

    12-24 2025 CALIFORNIA FIRE CODE

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

    ENERGY SYSTEMS

    1207.11.5 Electrical installation. ESS shall be installed in accordance with the California Electrical Code. Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing. Systems connected to the utility grid shall use inverters listed for utility interaction. (Material based on NFPA 855 2023 Ed.)

    1207.11.6 Fire detection. ESS installed in Group R-3 and R-4 occupancies shall comply with the following:

    1. Rooms and areas within dwelling units, sleeping units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section 907.2.11.
    2. A listed heat alarm shall be installed in locations where smoke alarms cannot be installed based on their listing.
  • CRC § 12-15 High relevance — show source text

    2025 CALIFORNIA FIRE CODE 12-15

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

    ENERGY SYSTEMS

    1. Dedicated-use buildings in compliance with Section 1207.7.1.

    1207.5.2.1 Mixed electrochemical energy systems. Where rooms, areas and walk-in units contain different types of electrochemical energy technologies, the total aggregate quantities of the systems shall be determined based on the sum of percentages of each technology-type quantity divided by the maximum allowable quantity of each technology type. The sum of the percentages shall not exceed 100 percent of the maximum allowable quantity.

    1207.5.3 Elevation. Electrochemical ESS shall not be located in the following areas:

    1. Where the floor is located more than 75 feet (22 860 mm) above the lowest level of fire department vehicle access.
    2. Where the floor is located below the lowest level of exit discharge.

    Exceptions: (Material based on NFPA 855 2023 Ed.)

    1. Lead-acid and nickel-cadmium battery systems less than 50 VAC and 60 VDC installed in facilities under the exclusive control of communications utilities in accordance with NFPA 76.

    2. Lead-acid and nickel-cadmium systems that are used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations.

    3. Lead-acid battery systems in uninterruptable power supplies listed and labeled in accordance with UL 1778, utilized for standby power applications, which is limited to not more than 10 percent of the floor area on the floor on which the ESS is located.

    4. Where approved, installations shall be permitted in underground vaults complying with the California Electrical Code, Article 450, Part III.

    5. Where approved by the fire code official, installations shall be permitted on higher and lower floors. 1207.5.4 Fire detection. An approved automatic smoke detection system or radiant energy-sensing fire detection system complying with Section 907.2 shall be installed in rooms, indoor areas and walk-in units containing electrochemical ESS. An approved radiant energy-sensing fire detection system shall be installed to protect open parking garage and rooftop installations. Alarm signals from detection systems shall be transmitted to a central station, proprietary or remote station service in accordance with NFPA 72, or where approved to a constantly attended location. Exception: Normally unoccupied, remote stand-alone telecommunications structures with a gross floor area of less than 1,500 square feet (139 m [2] ) utilizing lead-acid or nickel-cadmium batteries shall not be required to have a fire detection system installed. (Material based on NFPA 855 2023 Ed.)

    1207.5.4.1 System status. Lead-acid and nickel-cadmium battery systems that are used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations, shall be allowed to use the process control system to monitor the smoke or radiant energy-sensing fire detectors required in Section 1207.5.4. (Material based on NFPA 855 2023 Ed.) 1207.5.5 Fire suppression systems. Rooms and areas within buildings and walk-in units containing electrochemical ESS shall be protected by an automatic fire suppression system designed and installed in accordance with one of the following: 1.

  • CRC § 1207.7.1. High relevance — show source text

    Lead-acid and nickel-cadmium battery systems installed in Group U buildings and structures less than 1,500 square feet (139 m2) under the exclusive control of communi-
    cations utilities, and operating at less than 50 VAC and 60 VDC in accordance with NFPA 76, are not required to have an approved automatic smoke or fire detection
    system.|NA = Not Allowed.
    a. See Section 1207.7.1.
    b. See Section 1207.7.2.
    c. Where approved by the fire code official, fire suppression systems are permitted to be omitted in dedicated-use buildings located more than 100 feet (30.5 m) from buildings,
    lot lines, public ways, stored combustible materials, hazardous materials, high-piled stock and other exposure hazards.
    d. Where approved by the fire code official, alarm signals are not required to be transmitted to a central station, proprietary or remote station service in accordance with NFPA
    72, or a constantly attended location where local fire alarm annunciation is provided and trained personnel are always present.
    e. Lead-acid and nickel-cadmium battery systems installed in Group U buildings and structures less than 1,500 square feet (139 m2) under the exclusive control of communi-
    cations utilities, and operating at less than 50 VAC and 60 VDC in accordance with NFPA 76, are not required to have an approved automatic smoke or fire detection
    system.|

    1207.7.1 Dedicated-use buildings. For the purpose of Table 1207.7, dedicated-use ESS buildings shall be classified as Group F-1 occupancies and comply with all the following:

    1. The building shall only be used for ESS, electrical energy generation and other electrical grid-related operations.
    2. Occupants in the rooms and areas containing ESS are limited to personnel that operate, maintain, service, test and repair the ESS and other energy systems.
    3. No other occupancy types shall be permitted in the building.
    4. Administrative and support personnel shall be permitted in areas within the buildings that do not contain ESS, provided that: 4.1. The areas do not occupy more than 10 percent of the building area of the story in which they are located. 4.2. A means of egress is provided from the incidental use areas to the public way that does not require occupants to traverse through areas containing ESS or other energy system equipment. (Material based on NFPA 855 2023 Ed.)

    1207.7.2 Nondedicated-use buildings. For the purpose of Table 1207.7, nondedicated-use buildings include all buildings that contain ESS and do not comply with Section 1207.7.1 dedicated-use building requirements. (Material based on NFPA 855 2023 Ed.)

    1207.7.3 Dwelling units and sleeping units. ESS shall not be installed in sleeping units or in habitable spaces of dwelling units. (Material based on NFPA 855 2023 Ed.)

    1207.7.4 Fire-resistance-rated separations. Rooms and areas containing ESS shall include fire-resistance-rated separations as follows:

    1. In dedicated-use buildings, rooms and areas containing ESS shall be separated from areas in which administrative and support personnel are located.
    2. In nondedicated-use buildings, rooms and areas containing ESS shall be separated from other areas in the building.
  • CRC § 1207.2.1. High relevance — show source text

    The quantities and types of ESS to be installed. 4. Manufacturer’s specifications, ratings and listings of each ESS. 5. Description of energy (battery) management systems and their operation. 6. Location and content of required signage. 7. Details on fire suppression, smoke or fire detection, thermal management, ventilation, exhaust and deflagration venting systems, if provided. 8. Support arrangement associated with the installation, including any required seismic restraint. 9. A commissioning plan complying with Section 1207.2.1. 10. A decommissioning plan complying with Section 1207.2.3. 11. A fire safety and evacuation plan in accordance with Section 404.

    1207.1.5.1 Utilities applicability. Plans and specifications associated with ESS owned and operated by electric utilities as a component of the electric grid that are considered critical infrastructure documents in accordance with the provisions of the North American Electric Reliability Corporation and other applicable governmental laws and regulations shall be made available to the fire code official for viewing based on the requirements of the applicable governmental laws and regulations. (Material based on NFPA 855 2023 Ed.)

    1207.1.6 Hazard mitigation analysis. A failure modes and effects analysis (FMEA) or other approved hazard mitigation analysis shall be provided in accordance with Section 104.2.2 under any of the following conditions:

    1. Where ESS technologies not specifically identified in Table 1207.1.3 are provided.
    2. More than one ESS technology is provided in a single fire area where there is a potential for adverse interaction between technologies.
    3. Where allowed as a basis for increasing maximum allowable quantities. See Section 1207.5.2.
    4. Where required by the fire code official to address a potential hazard with an ESS installation that is not addressed by existing requirements.

    1207.1.6.1 Fault condition. The hazard mitigation analysis shall evaluate the consequences of the following failure modes. Only single failure modes shall be considered.

    1. A thermal runaway condition in a single electrochemical ESS unit.

    2. A mechanical failure of a nonelectrochemical ESS unit.

    3. Failure of any battery (energy) management system or fire protection system within the ESS equipment that is not covered by the product listing failure mode effects analysis (FMEA).

    4. Failure of any required protection system external to the ESS, including but not limited to ventilation (HVAC), exhaust ventilation, smoke detection, fire detection, gas detection or fire suppression system. (Material based on NFPA 855 2023 Ed.)

    1207.1.6.2 Analysis approval. The fire code official is authorized to approve the hazardous mitigation analysis provided that the consequences of the hazard mitigation analysis demonstrate:

    1. Fires will be contained within unoccupied ESS rooms or areas for the minimum duration of the fire-resistance-rated separations identified in Section 1207.7.4.
    2. Fires involving the ESS will allow occupants or the general public to evacuate to a safe location. (Material based on NFPA 855 2023 Ed.)

    1207.1.6.3 Additional protection measures. Construction, equipment and systems that are required for the ESS to comply with the hazardous mitigation analysis, including but not limited to those specifically described in Section 1207, shall be installed, maintained and tested in accordance with nationally recognized standards and specified design parameters.

  • CRC § 435.6.2 High relevance — show source text

    435.6.2 Safety padding. Padding material used on walls, floors and ceilings in Group I and R-2.1 occupancies shall be of an approved type tested in accordance with the procedures established by State Fire Marshal Standard 12-8-100, Room Fire Test for Wall and Ceil- ing Materials, California Code of Regulations, Title 24, Part 12.

    435.7 Fire protection system provisions.

    435.7.1 Automatic sprinkler systems in Group R-2.1, R-3.1 and R-4 occupancies. An automatic sprinkler system shall be installed where required in Section 903.

    435.7.2 Fire alarm systems in Group R-2.1 and R-4 occupancies. An approved fire alarm system shall be installed where required in Section 907.

    435.7.3 Smoke alarms in Groups R-2.1, R-3.1 and R-4 occupancies. Smoke alarms shall be installed where required in Section 907.2.11.2.

    435.7.4 Hearing impaired. See Section 907.5.2.3.4.

    435.8 Means of egress provisions.

    435.8.1 General. In addition to the general means of egress requirements of Chapter 10, this section shall apply to Group R-2.1, R-3.1 and R-4 occupancies.

    435.8.2 Number of exits.

    435.8.2.1 Group R-2.1, R-3.1 and R-4 occupancies shall have a minimum of two exits.

    Exception: Ancillary use areas or occupancies shall have egress as required by Section 1021.

    435.8.3 Egress arrangements.

    435.8.3.1 Egress through adjoining dwelling units shall not be permitted.

    435.8.3.2 Group R-3.1 occupancies housing non- ambulatory clients. In a Group R-3.1 occupancy, bedrooms used by nonambu- latory clients shall have access to at least one of the required exits which shall conform to one of the following: 1. Egress through a hallway or area into a bedroom in the immediate area which has an exit directly to the exterior and the corridor/hallway is constructed consistent with the dwelling unit interior walls. The hallway shall be separated from common areas by a solid wood door not less than 1 [3] / 8 inch (35 mm) in thickness, maintained self-closing or shall be auto- matic closing by actuation of a smoke detector installed in accordance with Section 716.2.6. 2. Egress through a hallway which has an exit directly to the exterior. The hallway shall be separated from the rest of the house by a wall constructed consistent with the dwelling unit interior walls and opening protected by a solid wood door not less than 1 [3] / 8 inch (35 mm) in thickness, maintained self-closing or shall be automatic closing by actuation of a smoke detector installed in accordance with Section 716.2.6.

  • CRC § 3.6 High relevance — show source text

    DC wiring shall be installed in_ metallic conduit or raceways when located within enclosed spaces in a building. Conduit shall run along the bottom of load bearing members.

    SECTION R330—ENERGY STORAGE SYSTEMS

    R330.1 General. Energy storage systems (ESS) shall comply with the provisions of this section.

    Exceptions:

    1. ESS listed and labeled for use in habitable spaces, in accordance with UL 9540 and where installed in accordance with the listing, the manufacturer’s instructions and the California Electrical Code.
    2. ESS less than 1 kWh (3.6 megajoules).

    R330.2 Equipment listings. Energy storage systems (ESS) shall be listed and labeled in accordance with UL 9540.

    Exception: Where approved, repurposed unlisted battery systems from electric vehicles are allowed to be installed outdoors or in detached sheds located not less than 5 feet (1524 mm) from exterior walls, property lines and public ways.

    R330.3 Installation. ESS shall be installed in accordance with the manufacturer’s instructions and their listing.

    R330.3.1 Spacing. Individual units shall be separated from each other by not less than 3 feet (914 mm) except where other separation distances are specified by the ESS listing and the manufacturer’s installation instructions.

    R330.4 Locations. ESS shall be installed only in the following locations:

    1. Detached garages and detached accessory structures.

    2. Attached garages separated from the dwelling unit living space in accordance with Section R302.6.

    3. Outdoors or on the exterior side of exterior walls located not less than 3 feet (914 mm) from doors and windows directly entering the dwelling unit, except where smaller separation distances are permitted by the UL 9540 listing and manufacturer’s installation instructions.

    4. Enclosed utility closets, basements, storage or utility spaces within dwelling units with finished or noncombustible walls and ceilings. Walls and ceilings of unfinished wood-framed construction shall be provided with not less than [5] / 8 -inch (15.9 mm) Type X gypsum wallboard. Openings into the dwelling shall be equipped with solid wood doors not less than 1 [3] / 8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 1 [3] / 8 inches (35 mm) in thickness, or doors with a 20-minute fire protection rating. Doors shall be self-latching and equipped with a self-closing or an automatic-closing device. Penetrations through the required gypsum wallboard into the dwelling shall be protected as required by Section R302.11, Item 4.

    � ESS shall not be installed in sleeping rooms, or closets or spaces opening directly into sleeping rooms.

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    BUILDING PLANNING

    R330.5 Energy ratings. Individual ESS units shall have a maximum rating of 20 kWh. The ratings of the ESS in each location shall not exceed the ratings in Table R330.5. The total aggregate ratings of ESS on the property shall not exceed 600 kWh.

    ESS installations exceeding the permitted individual or aggregate ratings shall be installed in accordance with Section 1207 of the California Fire Code.

    |TABLE R330.

  • CRC § 1207.9.6 High relevance — show source text

    1207.9.6 Open parking garages. ESS and associated equipment that are located in open parking garages shall comply with all of the following:

    1. ESS shall not be located within 50 feet (15 240 mm) of air inlets for building HVAC systems.

    Exception: This distance shall be permitted to be reduced to 25 feet (7620 mm) if the automatic fire alarm system monitoring the radiant-energy sensing detectors de-energizes the ventilation system connected to the air intakes upon detection of fire.

    1. ESS shall not be located within 25 feet (7620 mm) of exits leading from the attached building where located on a covered level of the parking structure not directly open to the sky above.
    2. An approved fence with a locked gate or other approved barrier shall be provided to keep the general public at least 5 feet (1524 mm) from the outer enclosure of the ESS. (Material based on NFPA 855 2023 Ed.)

    1207.10 Mobile ESS equipment and operations. Mobile ESS equipment and operations shall comply with Sections 1207.10.1 through 1207.10.7.7. (Material based on NFPA 855 2023 Ed.)

    TABLE 1207.10—MOBILE ENERGY STORAGE SYSTEMS (ESS) Col2 Col3
    COMPLIANCE REQUIRED COMPLIANCE REQUIRED DEPLOYMENTa
    Feature Section Section
    All ESS installations 1207.4 Yesb
    Fire suppression systems 1207.5.5 Yesc
    Maximum allowable quantities 1207.5.2 Yes
    Maximum enclosure size 1207.5.6 Yes
    Means of egress separation 1207.5.8 Yes
    Size and separation 1207.5.1 Yesd
    Smoke and automatic fire detection 1207.5.4 Yese
    Technology-specific protection 1207.6 Yes
    Vegetation control 1207.5.7 Yes
    a. See Section 1207.10.2.
    b. Mobile operations on wheeled vehicles and trailers shall not be required to comply with Section 1207.4.4 seismic and structural load requirements.
    c. Fire suppression system connections to the water supply shall be permitted to use approved temporary connections.
    d. In walk-in units, spacing is not required between ESS units and the walls of the enclosure.
    e. Alarm signals are not required to be transmitted to an approved location for mobile ESS deployed 30 days or less.    		 a. See Section 1207.10.2.
    b. Mobile operations on wheeled vehicles and trailers shall not be required to comply with Section 1207.4.4 seismic and structural load requirements.
    c. Fire suppression system connections to the water supply shall be permitted to use approved temporary connections.
    d. In walk-in units, spacing is not required between ESS units and the walls of the enclosure.
    e. Alarm signals are not required to be transmitted to an approved location for mobile ESS deployed 30 days or less.    		 a. See Section 1207.10.2.
    b. Mobile operations on wheeled vehicles and trailers shall not be required to comply with Section 1207.4.4 seismic and structural load requirements.
    c. Fire suppression system connections to the water supply shall be permitted to use approved temporary connections.
    d.
  • CRC § 907.2.8.2 High relevance — show source text

    907.2.8.2 Automatic smoke detection system. An automatic smoke detection system that activates the occupant notification system in accordance with Section 907.5 shall be installed throughout all interior corridors serving sleeping units.

    Exception: An automatic smoke detection system is not required in buildings that do not have interior corridors serving sleeping units and where each sleeping unit has a means of egress door opening directly to an exit or to an exterior exit access that leads directly to an exit.

    907.2.8.3 Smoke alarms. Single- and multiple-station smoke alarms shall be installed in accordance with Section 907.2.11.

    907.2.9 Groups R-2, R-2.1 and R-2.2 . Fire alarm systems and smoke alarms shall be installed in Group R-2 and R-2.1 occupancies as required in Sections 907.2.9.1 through 907.2.10.2.1.1. Group R-2.2 shall be equipped throughout with an automatic fire alarm system and shall have a manual fire alarm pull station at the 24-hour staff watch office.

    907.2.9.1 Manual fire alarm system. A manual fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group R-2 occupancies where any of the following conditions apply:

    1. Any dwelling unit or sleeping unit is located three or more stories above the lowest level of exit discharge.
    2. Any dwelling unit or sleeping unit is located more than one story below the highest level of exit discharge of exits serving the dwelling unit or sleeping unit.
    3. The building contains more than 16 dwelling units or sleeping units. 4. Congregate residences with more than 16 occupants.

    Exceptions:

    1. A fire alarm system is not required in buildings not more than two stories in height where all dwelling units or sleeping units and contiguous attic and crawl spaces are separated from each other and public or common areas by not less than 1-hour fire partitions and each dwelling unit or sleeping unit has an exit directly to a public way, egress court or yard.
    2. Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2 and the occupant notification appliances will automatically activate throughout the notification zones upon a sprinkler water flow.

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    1. A fire alarm system is not required in buildings that do not have interior corridors serving dwelling units and are protected by an approved automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2, provided that dwelling units either have a means of egress door opening directly to an exterior exit access that leads directly to the exits or are served by open-ended corridors designed in accordance with Section 1027.6, Exception 3.

    907.2.9.2 Smoke alarms. Single- and multiple-station smoke alarms shall be installed in accordance with Section 907.2.11.

  • CRC § 907.4.2.1 High relevance — show source text

    Exceptions: 1. Large family day-care. 2. Manual fire alarm boxes in sleeping units of Group I-2 occupancies shall not be required at exits if located at all care providers’ control stations or other constantly attended staff locations, provided that such manual fire alarm boxes are visible and provided with ready access, and the distances of travel required in Section 907.4.2.1 are not exceeded. 3. Occupant notification systems are not required to be activated where private mode signaling installed in accordance with NFPA 72 is approved by the fire code official and staff evacuation responsibilities are included in the fire safety and evacuation plan required by Section 404 of the California Fire Code .

    [F] 907.2.6.1 Reserved.

    [F] 907.2.6.2 Group I-2. A manual and automatic fire alarm system shall be installed in Group I-2 occupancies. Where automatic fire suppression systems or smoke detectors are installed, such systems or detectors shall be connected to the building fire alarm system.

    Exception: Where an entire facility is used for the housing of persons, none of whom are physically or mentally handicapped or nonambulatory, and are between the ages of 18 and 64, the buildings or structures comprising such facility shall be exempt from the provisions of this subsection relating to the installation of an automatic fire alarm system.

    907.2.6.2.1 Notification. The fire alarm notification system shall be in accordance with Section 907.5.2.5.

    907.2.6.2.2 Automatic fire detection. Smoke detectors shall be provided in accordance with this section. 1. In patient and client sleeping rooms. Actuation of such detectors shall cause a visual display on the corridor side of the room in which the detector is located and shall cause an audible and visual alarm at the respective nurse station. A nurse call system listed for this function is an acceptable means of providing the audible and visual alarm at the respective nurse station and corridor room display. Operation of the smoke detector shall not include any alarm veri- fication feature.

    Exception: In patient and client rooms equipped with existing automatic door closers having integral smoke detec- tor, the integral detector is allowed to substitute for the room smoke detector, provided it meets all the required alerting functions. 2. Group I-2 nurse stations. A minimum of one (1) smoke detector shall be installed at the nurse station and centrally located.

    3. In waiting areas and corridors onto which they open, in the same smoke compartment, in accordance with Section 407.2.1.

    1. In areas where patients are restrained, smoke detectors shall be installed at ceilings throughout all occupied areas and mechanical/electrical spaces of smoke compartments and in adjacent smoke compartments where occupants of those compartments utilize the same means of egress.

    [F] 907.2.6.3 Group I-3 occupancies. Group I-3 occupancies shall be equipped with a manual fire alarm system and automatic smoke detection system installed for alerting staff.

    Exception: An automatic smoke detection system is not required within temporary holding cells.

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    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

Frequently asked questions

Do I have to add detectors if my ESS is outdoors or on an exterior wall?

If the ESS is installed outdoors or on the exterior side of an exterior wall in an allowed location, § R330.7 applies to rooms/areas within the dwelling where ESS are installed. Outdoor or exterior installations are addressed elsewhere in R330 (locations and clearances) and in the CFC when larger—consult § R330.4 and CFC §1207 for those scenarios.

What if the smoke alarm manufacturer’s listing allows installation in the garage?

Install the smoke alarm per its listing and the residential smoke‑alarm rules (R310/R314). If the smoke alarm is permitted by listing in that garage location, you do not need a separate heat detector. § R330.7.

Are there special monitoring or central‑station requirements for these alarms?

The CRC's R330.7 requires smoke alarms (or listed heat alarms where appropriate) and interconnection; it does not add a central‑station transmission requirement for residential alarms. Larger ESS or installations requiring CFC §1207 treatment may have more stringent detection and notification rules; consult CFC §1207.5.4 for those cases.

Is a listed combination smoke/CO alarm acceptable?

R330.7 specifies smoke alarms (and heat alarms where smoke alarms can't be installed). Combination alarms are addressed elsewhere in the residential sections; use smoke‑listed devices per the referenced residential section and the device listing. § R330.7.

What if my ESS is repurposed (EV battery) and not UL 9540‑listed?

CRC allows certain repurposed unlisted EV battery systems outdoors or in detached sheds under limitations; however, if located inside the dwelling or attached garage, the code’s detection requirements per § R330.7 and the ESS listing/manufacturer instructions still control—consult R330.2 and R330.3 for listing/installation guidance.

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