New electrical standards coming into force on 15 April 2026 will change how home battery systems are installed across the UK.
The update to the building regulation BS 7671, published by the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI), introduces tighter rules on where batteries can safely be located.
Lofts and other high-risk areas are now excluded in an effort to improve fire safety and access.
Article continues belowWhat the new rules say
The new electric rules are set out in Amendment 4 to BS 7671:2018, the UK’s main wiring regulations, which are jointly published by the IET and BSI through the national wiring committee JPEL/64.
The updated guidance introduces a new dedicated section on stationary battery storage systems, including solar batteries, and sets out stricter requirements for their installation.
In practical terms, the rules state that home battery systems should not be installed in loft spaces or escape routes, such as stairways or hallways, where risk is considered higher and access for maintenance or emergency isolation is more difficult.
The update also introduces clearer expectations around safe installation conditions, including ventilation, physical access, and safe isolation points for maintenance.
Why the rules are changing
The revisions are largely driven by safety concerns linked to lithium-ion battery technology, which is now widely used in home energy storage systems.
The IET and BSI-backed standard focuses on reducing the risk of thermal runaway, a condition where battery cells overheat and can potentially ignite.
Lofts are considered unsuitable for several reasons highlighted in industry guidance aligned with BS 7671:
- High temperatures in roof spaces can increase battery stress
- Limited access can delay detection of faults or fires
- Escape routes increase the safety risk if a fire occurs
- Fire spread can be faster in loft spaces due to timber structures and insulation materials
Industry guidance accompanying the standard also stresses the need for batteries to be installed in locations where they can be safely isolated, inspected and maintained.
Where batteries can now be installed
While loft installations are no longer acceptable under the updated guidance, home battery systems can still be installed in a range of safer, more accessible locations.
The standards point towards installations in:
- Ground floor utility rooms
- Garages or dedicated plant areas
- External walls in suitable weatherproof enclosures
- Outbuildings where access and ventilation requirements are met
The key requirement is that systems must be installed in accessible, ventilated locations that do not compromise escape routes and allow safe maintenance and isolation.
In practice, this means homeowners and installers will need to plan battery placement more carefully, rather than treating loft spaces as a default storage location.
