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Choose where batteries may go (location and code)

Batteries need a protected space that firefighters can reach, away from where people sleep. Many codes now limit where battery systems may go and how much energy each space may hold.

How

  1. Never put a battery system in a bedroom, or in a closet or utility space that opens into a bedroom. Keep it out of living space.
  2. Example (US, 2021 IRC R328.4): allowed places are detached garages and accessory structures, attached garages separated from the home by gypsum board, and outside walls at least 3 ft (about 0.9 m) from doors or windows into the home.
  3. Utility closets, basements and storage spaces may also qualify if they meet the wall and ceiling covering rules. The 2018 and 2021 IRC allow no ESS in habitable space. Newer standards (UL 9540, 3rd edition) define a 'Suitable for Use in Residential Habitable Spaces' marking, but that route applies only where a newer code edition is adopted and the unit carries the marking.
  4. Example (US, 2021 IRC R328 and NFPA 855) for energy limits: each unit up to 20 kWh, up to 40 kWh in utility closets and basements, up to 80 kWh in garages, detached structures or outdoors. Keep about 3 ft between units unless test data allow less. Units must be listed to UL 9540.
  5. Example (Australia and New Zealand, AS/NZS 5139:2019 with Amendment 1, December 2025): rules cover restricted locations, clearances from exits and openings, and building materials within 1 m of the battery.
  6. Under that amendment a battery may sit within 600 mm of an opening only if the opening is wider than 900 mm, such as a garage door. Check the full clearance figures in the standard.
  7. Example (international): IEC 62485-5:2020 sets safety rules for stationary lithium-ion installations up to 1,500 V DC, homes included. Example (UK): the IET Code of Practice for Electrical Energy Storage Systems.
  8. Fire and Rescue NSW advises a cool, ventilated, low-traffic spot away from entries, exits, doors and windows.
  9. In a garage, protect the battery from vehicle impact where it is in the driving path (US example: California Residential Code R330.8).
  10. Keep clear working space in front of the batteries and equipment as the code and maker require.
  11. Plan an outdoor emergency shutdown where required (for example, NEC 706 asks for one at one and two family dwellings).

Safety: Large battery banks can deliver thousands of amps into a short circuit and can start fires. Keep metal tools and jewellery away from terminals. A battery fire next to a bedroom leaves no time to escape.

Do these first

Sources

  1. ESS separation and maximum quantities: 2021 residential requirements. UL Code Authorities, accessed 2026-11
  2. NEC Requirements for Energy Storage Systems. EC&M, accessed 2026-11
  3. Code of Practice for Electrical Energy Storage Systems, 3rd edition. The Institution of Engineering and Technology (IET), accessed 2026-11
  4. Energy Storage Systems (ESS) Installed at Dwellings (2021 IRC R328 locations). IAEI Magazine (International Association of Electrical Inspectors), accessed 2026-11
  5. California Residential Code R330.7 and R330.8: ESS fire detection and impact protection. GoCodeBook (California Residential Code mirror, US example), accessed 2026-11
  6. Changes to the battery standard (AS/NZS 5139:2019 Amendment 1, December 2025). NSW Government, Building Commission NSW (Australia), accessed 2026-11
  7. IEC 62485-5:2020: Safety requirements for stationary lithium-ion battery installations. Battery Design (summary of the IEC standard), accessed 2026-11
  8. Residential Battery Energy Storage Systems (BESS). Fire and Rescue NSW (Australia), accessed 2026-11

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