What actually changed on 15 April 2026
The UK's wiring regulations are set out in BS 7671, also known as the IET Wiring Regulations. Before this year, home batteries lived in a slightly awkward space inside that document. There was no dedicated chapter for them, so installers worked from a mix of manufacturer instructions, general electrical safety rules, and the standalone fire safety specification, PAS 63100:2024.
That changed on 15 April 2026, when the IET and BSI published Amendment 4 to BS 7671:2018. The headline addition is a new dedicated section for stationary secondary batteries, covering domestic and commercial energy storage. For the first time, UK homeowners and installers have a single, named chapter in the wiring regulations that says exactly what is required of a home battery installation.
Where you cannot install a home battery
The combined effect of the new BS 7671 chapter and PAS 63100:2024 is to formally rule out a number of locations that were already considered bad practice, but were sometimes used in older installations. The list below is consistent across both standards.
| Location | Allowed? | Why not |
|---|---|---|
| Loft, roof space or void | No | Extreme temperature swings, poor ventilation, hard to access, fire would spread to bedrooms below |
| Bedroom, or cupboard opening into a bedroom | No | Sleeping occupants must not be exposed to a battery thermal event |
| Stairs, landings, hallways used for escape | No | A battery fire here would block the route out of the building |
| Tight internal cupboard with no ventilation | No | Off-gassing during normal operation needs somewhere to go |
| Outdoors, within 1 metre of a door, window, vent or escape route | No | Smoke and gases must not be able to enter the home |
Two of these are genuinely new for UK practice. The explicit ban on loft installations is the biggest one, and is the change most homeowners will hear about. The other practical change is the formal 1 metre external clearance from windows and doors, which some older installations did not always observe.
Where you can install a home battery
The good news is that for the great majority of UK homes, the new rules just confirm what installers already do. PAS 63100 starts from the assumption that outdoor or outdoor-equivalent locations are best, and works inwards from there.
Compliant locations for a UK home battery in 2026:
- Attached garage, separated from the rest of the house by a fire-rated wall
- Detached garage or outbuilding, treated as outdoors for fire safety purposes
- External wall mount, in a weatherproof enclosure, at least 1 metre from doors, windows and vents
- Utility room or plant room, with adequate fire separation (typically REI 30 walls, ceiling and floor)
- Purpose-built battery enclosure, ground-mounted in a garden or yard
Most UK homes have at least one of these options. A typical Habo Energy install puts the battery on an external wall or inside a garage, and that pattern works just as well under the new rules as it did under the old ones. If you have already used our savings calculator and are weighing up a system, your existing site survey is almost certainly still valid.
Clearance, ventilation and detection
The new chapter in BS 7671 sets out the practical detail your installer will need to follow. Three areas matter most for homeowners.
Clearance around the unit
Most manufacturers already specify a minimum 30 cm of clear space on every side of the battery, and the same around the inverter. The new rules formalise the principle: the unit must not be boxed in by combustible materials, and there must be enough room around it to inspect, isolate and, if needed, fight a fire. Practically, that rules out tight under-stair cupboards and shelving units that sit flush against the battery.
Ventilation
Lithium iron phosphate (LFP) batteries, the chemistry used in nearly every modern UK home battery, off-gas a small amount of vapour during normal operation, and significantly more during a thermal event. The new chapter requires installations to consider both. In practice, this means a vented enclosure outdoors, or a room with passive ventilation indoors. Sealed cupboards are not acceptable.
Fire detection
PAS 63100 requires a smoke or multi-sensor alarm in any space where a battery is installed, with extra emphasis on infrequently visited locations like garages and plant rooms. Most newer UK homes already have interlinked alarms under building regulations, but if your battery is going into a garage that does not, your installer will likely need to add one.
What this means if you already own a home battery
Amendment 4 is not retrospective. If your system was installed legally and to the standard in force at the time, you do not have to move it. That said, if your battery is in one of the locations the new rules consider unsuitable, particularly a loft, it is worth a conversation with your installer.
- Check whether your manufacturer warranty still covers a loft install. Several major brands have quietly tightened temperature and location terms over the past two years.
- Make sure there is a working interlinked smoke alarm in the space.
- If the loft is poorly ventilated, ask whether a passive vent or louvre would be a sensible upgrade.
- Insurance is the unknown. Some home insurers are starting to ask where a battery is sited, so it is worth checking your policy schedule.
What this means if you are buying a battery in 2026
If you are ordering a battery between now and October 2026, ask your installer to confirm in writing that the design complies with BS 7671 Amendment 4 and PAS 63100:2024. A reputable MCS-certified installer will do this as a matter of course, but it is worth being explicit.
Three practical questions to ask:
- Where exactly will the battery be sited, and which clause of PAS 63100 covers that location?
- What fire separation, ventilation and detection are being added, if any?
- Will the installation paperwork list the design as compliant with BS 7671:2018+A4:2026, or with the previous amendment?
Beyond the location question, nothing else about choosing a battery has changed. The same rules of thumb apply: get the right capacity for your usage, pair it with a time-of-use tariff, and check the all-in cost rather than the headline price.
The bigger picture
The 2026 update is part of a multi-year tightening of the rules around home energy storage. Battery numbers in UK homes have grown roughly tenfold in five years, and the regulator and standards bodies are catching up. Expect further refinement to PAS 63100 over the next two years, particularly around external enclosure design and grid-edge cybersecurity.
For homeowners, the direction of travel is reassuring rather than restrictive. The basic shape of a sensible install (garage or external wall, with proper clearance and detection) has not changed, and the few locations now ruled out were never good ideas. If you are buying a battery in 2026, you have more confidence than ever that the installation will be safe, well-documented, and comparable across suppliers.
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