New electrical standards coming into force on 15 April 2026 will change how home battery systems are installed across the UK.
Update for Building regulation BS 7671, published by the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI), sets out strict rules on where batteries can be safely located.
Lofts and other high-risk areas are now excluded in an effort to improve fire safety and access.
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What the new rules say
This New Electric Regulations Amendments 4 to BS 7671:2018 are set out in the UK’s main wiring regulations, published jointly by the IET and BSI through National Wiring Committee JPEL/64.
The updated guidance introduces a new dedicated section on stationary battery storage systems, including Solar batteriesand sets strict requirements for their installation.
In practical terms, the regulations state that home battery systems should not be installed in loft spaces or escape routes, such as stairwells or hallways, where the risk is considered greater 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 are the rules changing?
Improvements have largely been motivated by safety concerns associated with lithium-ion battery technology, which is now widely used in home energy storage systems.
The IET and BSI-endorsed standard focuses on reducing the risk of thermal runaway, a condition where battery cells overheat and can potentially ignite.
Lofts are considered unsuitable for a number of reasons published in industry guidance aligned to BS 7671:
- High temperatures in roof spaces can increase battery stress
- Limited access can delay the detection of a fault or fire
- Exit routes increase the safety risk in the event of a fire
- Wood structures and insulation materials can cause fire to spread quickly in loft spaces
Industry guidance accompanying the standard also emphasizes the need to install batteries 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 refer to installation in:
- Ground floor utility room
- Garages or dedicated plant areas
- External walls in a suitable weatherproof enclosure
- Outbuildings where access and ventilation requirements are met
A key requirement is that systems must be installed in accessible, ventilated locations that do not compromise exit routes and allow safe maintenance and isolation.
In practice, this means that homeowners and installers will need to plan battery placement more carefully, rather than treating loft space as the default storage location.
