CFC · California Fire Code

How much ESS energy is allowed per fire area and what separation/fire-resistance is required?

The California Fire Code delegates numeric per‑fire‑area ESS limits to Table 1207.5 (see **§ 1207.5.2**). If you mix battery technologies use the percent‑of‑maximum method in **§ 1207.5.2.1**; electrochemical batteries are grouped ≤ **50 kWh** with **3 ft** spacing, exterior wall units are limited to **20 kWh** each, and ESS rooms generally require **2‑hour** fire‑resistance separations. Exceeding the table values requires an approved hazard mitigation analysis and/or large‑scale fire testing. filefile

Ask a question free See coverage

Last reviewed: July 6, 2026

What the code requires — plain English

The California Fire Code sets the maximum allowable energy per fire area for electrochemical energy storage systems (ESS) in Table 1207.5, and requires procedures to increase limits only with an approved hazard mitigation analysis or large‑scale fire testing. The general rule that limits fire‑area quantities is § 1207.5.2. Where different electrochemical technologies are mixed in one fire area, aggregate quantities must be calculated using the percent‑of‑maximum method in § 1207.5.2.1.

The single most important rule: consult Table 1207.5 for the numeric maximums for each technology and use § 1207.5.2 and § 1207.5.2.1 to determine allowed totals or how to combine technologies; increases require an approved hazard mitigation analysis and/or UL 9540A large‑scale testing.

Requirements in detail

Key, decision‑relevant thresholds and where to find them

Decision‑relevant item Value / rule Code reference
Where the numeric per‑fire‑area limits live Limits are listed in Table 1207.5 (per technology / fire area). § 1207.5.2
How to combine different electrochemical technologies in one fire area Sum the percent of each technology: (installed qty ÷ technology max from Table 1207.5); total percent must be ≤ 100%. § 1207.5.2.1
Allowing quantities above Table 1207.5 Allowed only with fire code official approval based on a hazard mitigation analysis (FMEA) and/or large‑scale fire testing. Exception to § 1207.5.2; see § 1207.1.6 and § 1207.1.7 filefile
Segregation of electrochemical ESS groups Groups ≤ 50 kWh; groups separated a minimum of 3 feet (914 mm) from other groups and walls. § 1207.5.1
Individual exterior‑wall unit maximum (exterior wall installations) Individual ESS units ≤ 20 kWh when mounted on exterior walls per the listed conditions. § 1207.8.4
Fire‑resistance rated separations between ESS rooms/areas and other building areas 2‑hour fire barriers and 2‑hour horizontal assemblies, as appropriate, to separate ESS rooms/areas from other building spaces. § 1207.7.4
Dedicated‑use building nuance In dedicated‑use buildings some Table 1207.5 maximums are handled differently (see indoor ESS table notes); nondedicated buildings must comply with § 1207.5.2. Table 1207.7 / Section notes — see § 1207.7.1 / § 1207.7.2 and Table 1207.7 summary (maximum quantities apply to nondedicated)

Notes:

  • The uploaded code pages reference Table 1207.5 as the controlling numeric table for maximum allowable quantities, but the actual table contents were not included in the provided files. You must consult the full text of Table 1207.5 in the California Fire Code to get the per‑technology numeric kWh limits.

How to increase allowable quantities (the approved paths)

  • Provide a hazard mitigation analysis (FMEA) under § 1207.1.6 demonstrating acceptable failure modes and consequences; the analysis must show fires will be contained for the duration of the fire‑resistance ratings in § 1207.7.4 and that occupants/public can evacuate safely. file
  • Provide large‑scale fire testing (UL 9540A) demonstrating non‑propagation and containment; the fire code official may approve larger capacities or reduced separations based on that testing (see § 1207.1.7). file

Exceptions & special cases

  • Exception permitting approval for rooms/areas that exceed Table 1207.5 amounts when supported by an approved hazard mitigation analysis and large‑scale fire testing. (Exception to § 1207.5.2.)
  • Lead‑acid and nickel‑cadmium battery systems used in certain communications utilities or utility control installations have limited exceptions in several places (see the exceptions listed with § 1207.5.1 and § 1207.5.2).
  • Dedicated‑use ESS buildings (Group F‑1 classification) have different occupancy and some installation rules; consult § 1207.7.1–§ 1207.7.4 and Table 1207.7 for differences (for example, some sprinkler / quantity rules are handled differently). file
  • For outdoor ESS, Table cross‑references in 1207.8 may mean Table 1207.5 limits are applied differently (remote outdoor installations can have different allowances). Also, exterior wall‑mounted units are individually limited to 20 kWh per unit under § 1207.8.4. file

Common mistakes

  • Assuming a fixed kWh per fire area without checking Table 1207.5 — the code delegates numeric limits to that table; the section text alone does not provide all numeric maximums. Always consult the table.
  • Forgetting to apply the mixed‑technology percentage method from § 1207.5.2.1 when more than one electrochemical technology is in the same fire area; simply adding kWh across technologies can produce a noncompliant total.
  • Not segregating ESS into ≤ 50 kWh groups (or not keeping the 3‑ft separation between groups/walls) for electrochemical systems where that requirement applies.
  • Overlooking required 2‑hour fire‑resistance rated separations between ESS rooms/areas and other occupancies in nondedicated buildings.
  • Attempting to rely on local large‑scale testing or manufacturer data without formal approval by the fire code official and documentation as required in §§ 1207.1.6–1207.1.7. file

Worked example — applying the rules (method, not invented table numbers)

The code text provided in the uploaded files does not include the numeric entries of Table 1207.5, so this worked example shows the calculation method you must use rather than giving a fixed kWh limit.

Scenario: a fire area contains:

  • 3 lithium‑ion ESS racks, total nameplate 300 kWh; and
  • 1 flow‑battery ESS rack, total nameplate 200 kWh.

Steps:

  1. Look up the maximum allowable quantities for each technology in Table 1207.5: call them M_Li (for lithium‑ion) and M_Flow (for flow battery). (Table contents must be read from the full code.)
  2. Apply the mixed‑technology aggregation method in § 1207.5.2.1: compute Percent_Li = (Installed_Li ÷ M_Li) × 100; Percent_Flow = (Installed_Flow ÷ M_Flow) × 100. The installation is acceptable if Percent_Li + Percent_Flow ≤ 100%.

Example with variable math (no invented M values):

  • Installed_Li = 300 kWh → Percent_Li = 300 ÷ M_Li × 100.
  • Installed_Flow = 200 kWh → Percent_Flow = 200 ÷ M_Flow × 100.
  • If Percent_Li + Percent_Flow ≤ 100 → compliant; if > 100 → exceedances must be addressed.

Other simultaneous requirements that must be met:

  • Grouping/segregation: electrochemical ESS must be arranged in groups not exceeding 50 kWh and groups separated 3 ft from other groups/walls where that requirement applies. If your physical racks exceed 50 kWh per “group,” you must reconfigure into compliant groups or pursue an approved exception.
  • Fire‑resistance separation: the ESS room or area must meet the required 2‑hour fire‑resistance rated separations to adjacent building areas unless the installation qualifies for a different arrangement under other sections (and that requirement is part of the approval of any hazard mitigation analysis).
  • If your totals exceed Table 1207.5, prepare a hazard mitigation analysis per § 1207.1.6 and, if required by the fire code official, UL 9540A testing per § 1207.1.7 to support an increase. file

Related provisions (quick list)

  • § 1207.5.1 — Size and separation (groups ≤ 50 kWh, 3 ft separation).
  • § 1207.5.2 — Maximum allowable quantities (numeric limits located in Table 1207.5).
  • § 1207.5.2.1 — Mixed electrochemical energy systems aggregation method (percent‑of‑maximum).
  • § 1207.1.6 — Hazard mitigation analysis (FMEA) requirements and acceptance criteria.
  • § 1207.1.7 — Large‑scale fire testing (UL 9540A) requirements for propagation/containment evidence.
  • § 1207.7.4 — Fire‑resistance‑rated separations (2‑hour fire barriers/horizontal assemblies).
  • § 1207.8.4 — Exterior wall installations (individual ESS unit max 20 kWh, separation conditions).

If you want, I can:

  • Pull the actual numeric entries from Table 1207.5 (if you upload the pages that include that table or confirm you want me to search the full code online), or
  • Run a sample compliance calculation using the actual table numbers once you provide the Table 1207.5 content.

Code references

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

  • CFC § 1207.5.1 High relevance — show source text

    For electrochemical ESS units rated in amp-hours, kWh shall equal rated voltage times the amp-hour rating divided by 1,000.
    b. Shall include vanadium, zinc-bromine, polysulfide-bromide and other flowing electrolyte-type technologies.|

    1207.5.1 Size and separation. Electrochemical ESS shall be segregated into groups not exceeding 50 kWh (180 megajoules). Each group shall be separated a minimum of 3 feet (914 mm) from other groups and from walls in the storage room or area. The storage arrangements shall comply with Chapter 10.

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

    1. Lead-acid and nickel-cadmium battery systems in facilities under the exclusive control of communications utilities and operating at less than 50 VAC and 60 VDC 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, and limited to not more than 10 percent of the floor area on the floor on which the ESS is located.

    4. The fire code official is authorized to approve larger capacities or smaller separation distances based on large-scale fire testing complying with Section 1207.1.5.

    1207.5.2 Maximum allowable quantities. Fire areas within rooms, areas and walk-in units containing electrochemical ESS shall not exceed the maximum allowable quantities in Table 1207.5.

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

    1. Where approved by the fire code official, rooms, areas and walk-in units containing electrochemical ESS that exceed the amounts in Table 1207.5 shall be permitted based on a hazardous mitigation analysis in accordance with Section 1207.1.6 and large-scale fire testing complying with Section 1207.1.7.
    2. Lead-acid and nickel-cadmium battery systems installed in facilities under the exclusive control of communications utilities, and operating at less than 50 VAC and 60 VDC in accordance with NFPA 76.

    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.
  • CFC § 4.1. High relevance — show source text

    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.

    Separation shall be provided by 2-hour fire barriers constructed in accordance with Section 707 of the California Building Code and 2-hour horizontal assemblies constructed in accordance with Section 711 of the California Building Code, as appropriate. (Material based on NFPA 855 2023 Ed.)

    1207.8 Outdoor installations. Outdoor installations shall be in accordance with Sections 1207.8.1 through 1207.8.3. Exterior wall installations for individual ESS units not exceeding 20 kWh shall be in accordance with Section 1207.8.4. (Material based on NFPA 855 2023 Ed.)

    2025 CALIFORNIA FIRE CODE 12-19

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

    ENERGY SYSTEMS

  • CFC § 307.1 High relevance — show source text

    Percentages shall be of the maximum allowable quantity per control area shown in Tables 307.1(1) and 307.1(2), with all increases allowed in the notes to those tables.
    b. Separation shall include fire barriers and horizontal assemblies as necessary to provide separation from other portions of the building.|a. Percentages shall be of the maximum allowable quantity per control area shown in Tables 307.1(1) and 307.1(2), with all increases allowed in the notes to those tables.
    b. Separation shall include fire barriers and horizontal assemblies as necessary to provide separation from other portions of the building.|a. Percentages shall be of the maximum allowable quantity per control area shown in Tables 307.1(1) and 307.1(2), with all increases allowed in the notes to those tables.
    b. Separation shall include fire barriers and horizontal assemblies as necessary to provide separation from other portions of the building.|a. Percentages shall be of the maximum allowable quantity per control area shown in Tables 307.1(1) and 307.1(2), with all increases allowed in the notes to those tables.
    b. Separation shall include fire barriers and horizontal assemblies as necessary to provide separation from other portions of the building.|a. Percentages shall be of the maximum allowable quantity per control area shown in Tables 307.1(1) and 307.1(2), with all increases allowed in the notes to those tables.
    b. Separation shall include fire barriers and horizontal assemblies as necessary to provide separation from other portions of the building.|

    [F] 414.2.3 Number. The maximum number of control areas within a building shall be in accordance with Table 414.2.2. For the purposes of determining the number of control areas within a building, each portion of a building separated by one or more fire walls complying with Section 706 shall be considered a separate building.

    [F] 414.2.4 Fire-resistance rating requirements. The required fire-resistance rating for fire barriers shall be in accordance with Table 414.2.2. The floor assembly of the control area and the construction supporting the floor of the control area shall have a fireresistance rating of not less than 2 hours.

    Exception: The floor assembly of the control area and the construction supporting the floor of the control area are allowed to be 1-hour fire-resistance-rated in buildings of Types IIA, IIIA, IV and VA construction, provided that both of the following conditions exist:

    1. The building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    2. The building is three or fewer stories above grade plane.

    [F] 414.2.5 Hazardous material in Group M display and storage areas and in Group S storage areas. Hazardous materials located in Group M and Group S occupancies shall be in accordance with Sections 414.2.5.1 through 414.2.5.4.

  • CFC § 1207.1.7. High relevance — show source text
    1. Clearances to buildings are permitted to be reduced to 3 feet (914 mm) where a weatherproof enclosure constructed of noncombustible materials is provided over the ESS, and it has been demonstrated that a fire within the enclosure will not ignite combustible materials outside the enclosure based on large-scale fire testing complying with Section 1207.1.7.

    1207.8.4 Exterior wall installations. ESS shall be permitted to be installed outdoors on exterior walls of buildings when all of the following conditions are met:

    1. The maximum energy capacity of individual ESS units shall not exceed 20 kWh.
    2. The ESS shall comply with applicable requirements in Section 1207.
    3. The ESS shall be installed in accordance with the manufacturer’s instructions and their listing.
    4. Individual ESS units shall be separated from each other by at least 3 feet (914 mm).
    5. The ESS shall be separated from doors, windows, operable openings into buildings or HVAC inlets by at least 5 feet (1524 mm).

    Exception: Where approved, smaller separation distances in Items 4 and 5 shall be permitted based on large-scale fire testing complying with Section 1207.1.7. (Material based on NFPA 855 2023 Ed.)

    12-20 2025 CALIFORNIA FIRE CODE

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

    ENERGY SYSTEMS

    1207.9 Special installations. Rooftop and open parking garage ESS installations shall comply with Sections 1207.9.1 through 1207.9.6.

    TABLE 1207.9—SPECIAL ESS INSTALLATIONS Col2 Col3 Col4
    COMPLIANCE REQUIRED COMPLIANCE REQUIRED ROOFTOPSa OPEN PARKING GARAGESb
    Feature Section Section Section
    All ESS installations 1207.4 Yes Yes
    Clearance to exposures 1207.9.3 Yes Yes
    Fire suppression systems 1207.9.4 Yes Yes
    Maximum allowable quantities 1207.5.2 Yes Yes
    Maximum enclosure size 1207.5.6 Yes Yes
    Means of egress separation 1207.5.8 Yes Yes
    Open parking garage installations 1207.9.6 No Yes
    Rooftop installations 1207.9.5 Yes No
    Size and separation 1207.5.1 Yes Yes
    Smoke and automatic fire detection 1207.5.4 Yes Yes
    Technology-specific protection 1207.6 Yes Yes
    a. See Section 1207.9.1.
    b. See Section 1207.9.2.    		 a. See Section 1207.9.1.
    b. See Section 1207.9.2.    		 a. See Section 1207.9.1.
    b. See Section 1207.9.2.    		 a. See Section 1207.9.1.
    b. See Section 1207.9.2.

    1207.9.1 Rooftop installations. For the purpose of Table 1207.9, rooftop ESS installations are those located on the roofs of buildings. (Material based on NFPA 855 2023 Ed.)

  • CFC § 1207.7.2 High relevance — show source text

    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.

    Separation shall be provided by 2-hour fire barriers constructed in accordance with Section 707 of the California Building Code and 2-hour horizontal assemblies constructed in accordance with Section 711 of the California Building Code, as appropriate. (Material based on NFPA 855 2023 Ed.)

    1207.8 Outdoor installations. Outdoor installations shall be in accordance with Sections 1207.8.1 through 1207.8.3. Exterior wall installations for individual ESS units not exceeding 20 kWh shall be in accordance with Section 1207.8.4. (Material based on NFPA 855 2023 Ed.)

    2025 CALIFORNIA FIRE CODE 12-19

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

    ENERGY SYSTEMS

    TABLE 1207.8—OUTDOOR ESS INSTALLATIONSa Col2 Col3 Col4
    COMPLIANCE REQUIRED COMPLIANCE REQUIRED REMOTE INSTALLATIONSa INSTALLATIONS NEAR EXPOSURESb
    Feature Section Section Section
    All ESS installations 1207.4 Yes Yes
    Clearance to exposures 1207.8.3 Yes Yes
    Fire suppression systems 1207.5.5 Yesc Yes
    Maximum allowable quantities 1207.5.2 No Yes
    Maximum enclosure size 1207.5.6 Yes Yes
    Means of egress separation 1207.5.8 Yes Yes
    Size and separation 1207.5.1 No Yesd
    Smoke and automatic fire detection 1207.5.4 Yes Yes
    Technology-specific protection 1207.6 Yes Yes
    Vegetation control 1207.5.7 Yes Yes
    a. See Section 1207.8.1.
    b. See Section 1207.8.2.
    c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
    d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.    		 a. See Section 1207.8.1.
    b. See Section 1207.8.2.
    c. Where approved by the fire code official, fire suppression systems are permitted to be omitted.
    d. In outdoor walk-in units, spacing is not required between ESS units and the walls of the enclosure.    		 a.
  • CFC § 1207.6.4 Medium relevance — show source text

    1207.6.4 Safety caps. Where required by Table 1207.6 or elsewhere in this code, vented batteries and other ESS shall be provided with flame-arresting safety caps.

    1207.6.5 Thermal runaway. Where required by Table 1207.6 or elsewhere in this code, batteries and other ESS shall be provided with a listed device or other approved method to prevent, detect and minimize the impact of thermal runaway.

    1207.7 Indoor installations. Indoor ESS installations shall be in accordance with Sections 1207.7.1 through 1207.7.4. (Material based on NFPA 855 2023 Ed.)

    12-18 2025 CALIFORNIA FIRE CODE

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

    ENERGY SYSTEMS

    TABLE 1207.7—INDOOR ESS INSTALLATIONS Col2 Col3 Col4
    COMPLIANCE REQUIRED COMPLIANCE REQUIRED DEDICATED-USE
    BUILDINGSa    		 NONDEDICATED-USE
    BUILDINGSb
    Feature Section Section Section
    Dwelling units and sleeping units 1207.7.3 NA Yes
    COMPLIANCE REQUIRED COMPLIANCE REQUIRED DEDICATED-USE
    BUILDINGSa    		 NONDEDICATED-USE
    BUILDINGSb
    Feature Section Section Section
    Elevation 1207.5.3 Yes Yes
    Fire suppression systems 1207.5.5 Yesc Yes
    Fire-resistance-rated separations 1207.7.4 Yes Yes
    General installation requirements 1207.4 Yes Yes
    Maximum allowable quantities 1207.5.2 No Yes
    Size and separation 1207.5.1 Yes Yes
    Smoke and automatic fire detectione 1207.5.4 Yesd Yes
    Technology specific protection 1207.6 Yes Yes
    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.    		 NA = Not Allowed.
    a. See Section 1207.7.1.
    b. See Section 1207.7.2.
    c.
  • CFC § 1207.7.1. Medium 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.
  • CFC § 1207.2.1. Medium 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.

  • CFC § 1207.9.6 Medium 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.
  • CFC § 1207.1.6.1 Medium relevance — show source text

    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.

    1207.1.7 Large-scale fire test. Where required elsewhere in Section 1207, large-scale fire testing shall be conducted on a representative ESS in accordance with UL 9540A. The testing shall be conducted or witnessed and reported by an approved testing laboratory and show that a fire involving one ESS will not propagate to an adjacent ESS, and where installed within buildings, enclosed areas and walk-in units will be contained within the room, enclosed area or walk-in unit for the duration of the test. The test report shall be provided to the fire code official for review and approval in accordance with Section 104.2.2. (Material based on NFPA 855 2023 Ed.)

    2025 CALIFORNIA FIRE CODE 12-11

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

    ENERGY SYSTEMS

    1207.1.8 Fire remediation. Where a fire or other event has damaged the ESS and ignition or re-ignition of the ESS is possible, the system owner, agent or lessee shall take the following actions, at their expense, to mitigate the hazard or remove damaged equipment from the premises to a safe location.

    1207.1.8.1 Fire mitigation personnel. Where, in the opinion of the fire code official, it is essential for public safety that trained personnel be on-site to respond to possible ignition or re-ignition of a damaged ESS, the system owner, agent or lessee shall dispatch within 15 minutes one or more fire mitigation personnel to the premise, as required and approved, at their expense. These personnel shall remain on duty continuously after the fire department leaves the premise until the damaged energy storage equipment is removed from the premises, or earlier if the fire code official indicates the public safety hazard has been abated. (Material based on NFPA 855 2023 Ed.)

  • CFC § 1207.8.2 Medium relevance — show source text

    1207.8.2 Installations near exposures. For the purpose of Table 1207.8, installations near exposures include all outdoor ESS installations that do not comply with Section 1207.8.1 remote outdoor location requirements. (Material based on NFPA 855 2023 Ed.)

    1207.8.3 Clearance to exposures. ESS located outdoors shall be separated by a minimum of 10 feet (3048 mm) from the following exposures:

    1. Lot lines.

    2. Public ways.

    3. Buildings.

    4. Stored combustible materials.

    5. Hazardous materials.

    6. High-piled stock.

    7. Other exposure hazards.

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

    1. Clearances are permitted to be reduced to 3 feet (914 mm) where a 1-hour free-standing fire barrier suitable for exterior use and extending 5 feet (1524 mm) above and 5 feet (1524 mm) beyond the physical boundary of the ESS installation is provided to protect the exposure.

    2. Clearances to buildings are permitted to be reduced to 3 feet (914 mm) where noncombustible exterior walls with no openings or combustible overhangs are provided on the wall adjacent to the ESS and the fire-resistance rating of the exterior wall is a minimum of 2 hours.

    3. Clearances to buildings are permitted to be reduced to 3 feet (914 mm) where a weatherproof enclosure constructed of noncombustible materials is provided over the ESS, and it has been demonstrated that a fire within the enclosure will not ignite combustible materials outside the enclosure based on large-scale fire testing complying with Section 1207.1.7.

    1207.8.4 Exterior wall installations. ESS shall be permitted to be installed outdoors on exterior walls of buildings when all of the following conditions are met:

    1. The maximum energy capacity of individual ESS units shall not exceed 20 kWh.
    2. The ESS shall comply with applicable requirements in Section 1207.
    3. The ESS shall be installed in accordance with the manufacturer’s instructions and their listing.
    4. Individual ESS units shall be separated from each other by at least 3 feet (914 mm).
    5. The ESS shall be separated from doors, windows, operable openings into buildings or HVAC inlets by at least 5 feet (1524 mm).

    Exception: Where approved, smaller separation distances in Items 4 and 5 shall be permitted based on large-scale fire testing complying with Section 1207.1.7. (Material based on NFPA 855 2023 Ed.)

    12-20 2025 CALIFORNIA FIRE CODE

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

    ENERGY SYSTEMS

    1207.9 Special installations. Rooftop and open parking garage ESS installations shall comply with Sections 1207.9.1 through 1207.9.6.

Frequently asked questions

What is the single place to find the kWh limits for each battery technology?

The numeric limits are published in Table 1207.5; § 1207.5.2 directs you to that table for the per‑technology maximums.

Can I exceed Table 1207.5 if I have good mitigation measures?

Yes — but only with fire code official approval supported by a hazard mitigation analysis (FMEA) and, when required, large‑scale UL 9540A fire testing per §§ 1207.1.6 and 1207.1.7. file

How do I combine different battery types in one room?

Use the percent method in § 1207.5.2.1: installed quantity ÷ technology maximum (from Table 1207.5) for each technology; sum the percentages — must be ≤ 100%.

What is the 50 kWh / 3‑ft rule?

Electrochemical ESS must be segregated into groups not exceeding 50 kWh, with groups separated 3 feet (914 mm) from other groups and from walls where the requirement applies (see § 1207.5.1).

Are there required fire‑ratings for walls between ESS rooms and adjacent spaces?

Yes — rooms/areas containing ESS must include 2‑hour fire barriers and 2‑hour horizontal assemblies, as appropriate, per § 1207.7.4.

More in California Fire Code

Ask about the CFC

Get cited, plain-English answers on the California Fire Code for your project — any code section, any scenario.

Start Free Trial

Related in the CFC

What fire protection, suppression and large-scale fire-test requirements apply to ESS?

What are the rules for ESS cabinets, walk-in units and equipment enclosures?

What are the ventilation, thermal management, deflagration venting and detection requirements?

Design, Fire-Protection Systems & Safety Controls

California Fire Code