Regulation

From 15 October, a new battery storage chapter in the wiring regulations bans loft installs and puts a metre of clearance around anything sited outside

BS 7671:2018+A4:2026's new Chapter 57 is the first dedicated regulatory framework for stationary battery storage, requiring domestic systems to meet PAS 63100 on location, ventilation, fire protection, isolation and testing. It bans loft installs, bans siting in hallways or stairwells, and requires a metre of clearance from windows, doors and vents outside. It is not retroactive, but any alteration or addition to an existing system after 15 October has to meet the new rules.

12 September 2026 · Source: Cool Power

This is the electrical backdrop the Anker Solarbank 4 Pro piece on this site referenced without naming a specific date: batteries in the UK are already an electrician-installed, Part P job, wired to the consumer unit rather than plugged in, and from 15 October that installation has a dedicated compliance chapter to meet rather than general wiring regulations applied by inference. BS 7671:2018+A4:2026's Chapter 57 is the first time stationary battery storage gets its own named section in the wiring regs, and it does what MCS 3002 issue 6.0 did for solar mounting hardware in the same 2026 cycle: it turns what installers were already doing as best practice into a documented, checkable standard.

The specific restrictions matter for anyone in Sandwich, Deal or Ash planning a battery alongside a roof install. Lofts are out entirely, on the reasoning that they run too hot in summer and too cold in winter for a battery's safe operating range, and are usually poorly ventilated besides. Hallways, stairwells and anywhere that counts as an escape route are out too, on straightforward fire-safety grounds: a battery fault is not something you want between a household and the front door. Anything sited outside needs a full metre of clearance from windows, doors and vents. None of these are exotic requirements, most competent installers were already avoiding lofts and escape routes as a matter of common sense, but from 15 October they stop being a judgement call and start being a design certification requirement, backed by an installer's written confirmation of PAS 63100 compliance.

The rule is not retroactive: a battery already installed and compliant with the standard in force at the time stays compliant. The catch is in what counts as an alteration. Adding a second battery module to an existing system, or resiting an outdoor unit during other electrical work, after 15 October pulls the whole job into Chapter 57, even if the original install predates it. That is worth raising directly with an installer for anyone planning to expand a battery system already in place rather than starting from scratch, since "we're just adding capacity" does not exempt the addition from the new siting rules.

For anyone getting quotes now, ahead of the deadline, the practical question is the same one this site's MCS 3002 coverage raised for solar mounting: which standard is the installer actually designing against. A job specified and signed off before 15 October under the outgoing rules is fine as installed. A job that slips past that date, or gets varied after it, needs to meet Chapter 57, loft and escape-route exclusions and metre clearances included. Getting that answer in writing before work starts costs nothing and avoids a compliance argument after the battery is already on the wall.

Read the original: Cool Power. Commentary is Sandwich Solar's own editorial view; the original reporting is credited to its publisher.

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