Energy Storage System Permits

For state rules on energy storage systems, please refer to Superseding Guidance for Energy Storage Systems on Installations in One and Two-Family Dwellings. 

On December 9, 2022, the Commonwealth of Massachusetts adopted the NFPA 1 with MA Amendments to form 527 CMR 1.00 more formally known as the MA Fire Code. Table refers to Code Section 52.1.2 of NFPA 855.

527 CMR 1.00

Chapter 52 governs installation and operation of energy storage systems having a capacity greater than the those in the Threshold Quantity Table below (Table 1.3 NFPA 855).

  • Issuing Authority: Head of Fire Department.
  • Code Section: 52.1.2

52.1.2 Permits Permits where required, shall comply with Section 1.12 Prior to installation, plans shall be submitted and approved by the AHJ (Fire Department) Construction documentation shall include the documents required in of NFPA 855.

NFPA 855 (2020)

1.3 Application

This standard applies to ESS exceeding the values shown in Table 1.3.

1.3.2 ESS installed in 1 and 2 Family dwellings and townhouses shall comply with NFPA 855 Chapter 15

Table 1.3 Threshold Quantities
ESS TechnologyAggregate Capacity (kWh)*Aggregate Capacity (MJ)
Battery ESS

Lead-Acid, all types70252
Nickel including Ni-Cad, Ni-MH, and Ni-Zn**
Lithium-ion, all types
Sodium nickel chloride
Flow batteries***
Other battery technologies
Batteries in one- and two-family dwellings and townhouse units
Capacitor ESS

Electrochemical double layer capacitors****
Other ESS

All other ESS70252

*For ESS units rated in amp-hrs, kWh equals maximum rated voltage multiplied by amp-hr rating divided by 1000.
**Nickel battery technologies include nickel cadmium (Ni-Cad), nickel metal hydride (Ni-MH), and nickel zinc (Ni-Zn).
***Includes vanadium, zinc-bromine, polysulfide-bromide, and other flowing electrolyte-type technologies.
****Capacitors used for power factor correction, filtering, and reactive power flow are exempt.

The plans and specifications associated with an ESS and its intended installation, replacement or renewal, commissioning, and use shall be submitted to the AHJ for approval and include the following:

  1. Location and layout diagram of the room or area in which the ESS is to be installed
  2. Details on hourly fire-resistant-rated assemblies provided or relied upon in relation to the ESS
  3. The quantities and types of ESS units
  4. Manufacturer's specifications, ratings, and listings of ESS
  5. Description of energy storage management systems and their operation
  6. Location and content of required signage
  7. Details on fire suppression, smoke or fire detection, gas detection, thermal management, ventilation, exhaust, and deflagration venting systems, if provided
  8. Support arrangement associated with the installation, including any required seismic support

Chapter 15 One- and Two-Family Dwellings and Townhouse Units

15.1* General. ESS installations associated with one - or two-family dwellings or townhouse units shall comply with the requirements of this chapter.

15.2 Equipment Listings.

15.2.1 ESS 1 kWh or greater in maximum stored energy shall be listed and labeled in accordance with UL 9540.

15.2.2 ESS listed and labeled solely for utility or commercial use shall not be used for residential applications.

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

15.4 Commissioning.

15.4.1 ESS installed in one- and two-family dwellings and townhouse units shall be commissioned as follows:

  1. Verify that the system is installed in accordance with the approved plans and manufacturer’s instructions and is operating properly
  2. Provide a copy of the manufacturer’s installation, operation, and maintenance instructions provided with the listed system
  3. Provide training on the proper operation and maintenance of the system to the system owner
  4. Provide a label on the installed system containing the contact information for the qualified maintenance and service providers

15.4.2 Where the system is installed in a one- or two-family dwelling or townhouse unit that is owned by the builder and has yet to be sold, commissioning shall be conducted as outlined in Section 15.4, and the builder shall then transfer the required information in Section 15.4 to the home owner when the property is sold.

15.5 ESS Spacing. Individual ESS units shall be separated from each other by a minimum of 3 ft (914 mm) unless smaller separation distances are documented to be adequate as approved by the AHJ, based on large-scale fire testing complying with 4.1.5.

15.6 Location

15.6.1 ESS shall only be installed in the following locations:

  1. In attached garages separated from the dwelling unit living area and sleeping units in accordance with the local building code
  2. In detached garages and detached accessory structures
  3. Outdoors on exterior walls or on the ground located a minimum of 3 ft (914 mm) from doors and windows
  4. In enclosed utility closets and storage or utility spaces If the room or space where the ESS is to be installed is not finished, the walls and ceiling of the room or space shall be protected with not less than 5∕8 in. Type X gypsum board. (A building permit may be required to construct the space)

15.6.2 ESS shall not be installed in living area of dwelling units or in sleeping units other than within utility closets and storage or utility spaces.

15.7 Energy Ratings. Individual ESS units shall have a maximum stored energy of 20 kWh.

15.7.1 The aggregate rating amount within a dwelling, garage, or accessory structure shall not exceed the following:

  1. 40 kWh within utility closets and storage or utility spaces
  2. 80 kWh in attached or detached garages and detached accessory structures
  3. 80 kWh on exterior walls
  4. 80 kWh in outdoor installations

15.7.2 ESS installations with an aggregate energy rating exceeding that allowed by 15.7.1 shall comply with Chapters 4 through 9.

15.7.3* The use of an electric-powered vehicle to power the dwelling while parked shall comply with Section 15.13.

15.8 Electrical Installation. ESS shall be installed in accordance\ with NFPA 70.

15.8.1 Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing.

15.8.2 Systems connected to the utility grid shall use inverters listed for utility interaction.

15.9 Fire Detection.

15.9.1 Interconnected smoke alarms shall be installed throughout the dwelling, including in rooms, attached garages, and areas in which ESS are installed in compliance with local building code. (If system doesn’t already exist, then a floor plan diagram of the house with device locations and device spec sheet. If it is a new system, it must be included as part of the electrical permit)

15.9.2 Where ESS are installed in an attached garage or an area in which smoke alarms cannot be installed in accordance with their listing, an interconnected listed heat alarm shall be installed and be connected to the smoke alarm system required by the local building code.

15.10 Protection from Impact. Stationary storage battery systems installed in a location subject to vehicle damage shall be protected by approved barriers.

15.11 Exhaust Ventilation. Indoor installations of ESS that include batteries that produce hydrogen or other flammable gases during charging shall meet the exhaust ventilation requirements in accordance with Section 4.9.

15.12 Toxic and Highly Toxic Gas. ESS that have the potential to release toxic or highly toxic gas during charging, discharging, and normal use conditions shall be installed outdoors.

15.13 Electric Vehicle Use.

15.13.1 The temporary use of the dwelling unit owner’s or occupant’s electric-powered vehicle to power the dwelling while parked in an attached or detached garage or outside shall comply with the vehicle manufacturer’s instructions and NFPA 70.

15.13.2 The temporary use of the dwelling unit owner’s occupant’s electric-powered vehicle to power the dwelling while parked in an attached or detached garage or outside shall not exceed 30 days.