Where can a home battery go in a UK house? A garage, an outside wall or ground enclosure, or an indoor utility or plant room with proper fire separation are the compliant options. A loft, a bedroom, and any escape route, meaning a hallway, staircase or landing, are ruled out, and that ban covers protected fire-rated escape routes as well as ordinary ones. The rules come from PAS 63100:2024, the fire-safety specification for home batteries, and BS 7671 Amendment 4, whose new Chapter 57 becomes the wiring standard for new battery work once the current edition is withdrawn on 15 October 2026.
Get this right before you sign, not after the installer has picked the cheapest cable run. Where the battery sits drives fire safety, your warranty, your home insurance, winter performance and whether the work passes building control. I fitted my own system and have run a 15 kWh Fogstar rack battery every day since 2023, so I know from the install itself that moving a commissioned battery is not a small job: it means disconnecting a live unit, remounting it and paying for more electrical work. The location is the part that is most expensive to undo.
Jump to the question you have:
- The full location matrix
- Can it go in the loft?
- Can it go in the garage?
- Can it go outside?
- Utility room, cupboard or hallway?
- Already got one in the wrong place?
- What to demand from your installer
Where can a home battery actually go? The location matrix
This guide covers a typical UK home. PAS 63100 draws its own boundary: it applies to dwellings up to 200 square metres of floor area, and it does not cover high-risk residential buildings such as tall blocks of flats, second-life batteries built from used cells, or any system wired in before your meter. A larger house or one of those cases needs project-specific advice from a fire-safety competent designer.
Six questions screen most locations quickly. Does the spot block an escape route? Is it separated from the rest of the house by fire-resisting construction? Can it ventilate to outside air? Does the temperature stay inside the battery’s rated window? Can water or flooding reach it? Can a person, or a firefighter, safely get to it? Run a candidate spot past those six and the answer usually falls out. They are a homeowner’s first filter, not the whole test: your installer still has to complete the full PAS 63100 checks, which include the manufacturer’s arc-flash assessment, the stored-energy limits, impact protection, fire detection and clearance from stored fuel.
| Location | Compliant? | What the rules require | Practical note |
|---|---|---|---|
| Detached garage or outbuilding | Usually yes | Counts as outdoors; also applies to an outbuilding joined to the house by a wall rated to about 120 minutes of fire resistance (REI 120); impact protection to IK10 where a vehicle could strike it | Often the easiest compliant spot; up to 80 kWh total allowed here |
| Attached or integral garage | Often yes, with conditions | Fire-resisting separation of at least about 60 minutes (REI 60) from the living space; must not block an internal door used as an escape route; fresh-air ventilation; IK10 impact protection near vehicles | Common real-world location |
| External wall or garden enclosure | Usually yes, often preferred | Weatherproof rated enclosure; at least 1 m from windows, doors, vents and escape routes; at least 2 m from stored fuel or flammables; the wall’s fire performance kept intact; out of flood reach | Lowest risk to occupants; watch cold-weather performance |
| Utility or plant room | Yes, with conditions | Fire-resisting separation of at least about 30 minutes (REI 30) from sleeping rooms and escape routes; fresh-air ventilation to outside; interlinked fire detection | Fine when built properly; not a sealed cupboard |
| Kitchen | Possible, rarely chosen | Not a sleeping room or escape route, so not banned, but needs ventilation, fire separation and at least 2 m from any gas cylinder or stored fuel | Habitable and usually cramped; a utility room is normally the better call |
| Basement or cellar | Only with outside access | Prohibited if it has no route to the outside of the building; otherwise needs fire separation, fresh-air ventilation and detection | Damp and flood risk often rule it out anyway |
| Loft or attic | No | Expressly excluded, along with voids and roof spaces | Heat, access and joist loading are extra problems on top |
| Bedroom or any room used for sleeping | No | Prohibited, including any cupboard that opens into one | Fire and smoke risk to sleepers |
| Hallway, stairs or landing | No | Prohibited on any escape route, protected or not | The way out has to stay clear |
| Under-stairs or sealed cupboard | Usually no | An escape-route cupboard is banned; a sealed one fails the fresh-air ventilation rule | Works only if it ventilates outside, is fire-separated and has detection, which is rare under stairs |
The two rulebooks behind every siting decision
PAS 63100:2024 is the BSI specification titled Protection against fire of battery energy storage systems for use in dwellings, published on 20 March 2024 and sponsored by the UK government. It is free to download from BSI Knowledge. It sets out where a domestic battery can and cannot go, what fire separation an indoor spot needs, and how influences such as temperature and water affect the choice. It is a specification, not a law, but it is the fire-safety benchmark the industry works to.
BS 7671 Amendment 4 was published on 15 April 2026, and it adds a dedicated Chapter 57 that brings together and expands the wiring requirements for stationary battery installations. Installers can work to Amendment 4 now. From 15 October 2026 the previous edition is withdrawn, so from that date new work claiming to conform to the current wiring standard has to meet it. BS 7671 is not itself a law, and it lets a designer justify a departure, but it is the standard building control, insurers and certification schemes expect a fixed electrical installation to follow. Its battery siting rules are aligned with PAS 63100.
Falling short of these standards is not in itself a criminal offence. The cost lands elsewhere, and it helps to separate the pieces, because installers and blogs often blur them:
- A manufacturer can decline a warranty claim if the unit was installed outside its stated conditions.
- A home insurer can question a fire claim if the installation did not meet the recognised standard.
- The electrical work needs a BS 7671 Electrical Installation Certificate, plus the MCS battery-standard paperwork where the installer is MCS-certified.
- Adding the battery has to be notified to your DNO under G98, or applied for under G99 where the total capacity is larger, at or before connection.
- Building control runs under building regulations that differ by UK nation, so the evidence you need depends on where you live.
Can a solar battery be installed in a loft in the UK?
No. PAS 63100 expressly excludes voids, roof spaces and lofts, and BS 7671 Chapter 57 aligns with that. The standard states the exclusion plainly rather than giving its reasons, but the practical case against a loft is strong: summer temperatures well above a lithium battery’s rated range, little or no fresh-air ventilation to outside, combustible timber close by, and awkward access for anyone maintaining it or fighting a fire above where people sleep.
Weight is a separate practical problem. A domestic battery is a heavy, concentrated point load, and most loft joists were never sized to carry one. Any proposed load has to be assessed against the actual structure, so even where the fire rules did not already exclude the loft, the joists often would.
If the loft is the only space you think you have, that points to the battery belonging outside or in the garage instead. An outdoor wall unit or a garage install answers the heat, ventilation, access and loading problems in one move, and it keeps the battery away from the bedrooms.
Can a home battery go in the garage?
A garage is a common compliant location, but an attached garage and a detached garage are treated differently. A detached garage or outbuilding counts as an outdoor location. So does an outbuilding joined to the house by a wall rated to about 120 minutes of fire resistance (REI 120). An attached or integral garage is indoors, so it is allowed only where fire-resisting construction of at least about 60 minutes (REI 60) separates it from the living space, and where the battery does not sit on or block an internal door used as an escape route.
The trap with an integral garage is that door into the house. If it is part of your escape route, the battery cannot compromise it, so a competent installer positions the unit to keep a fire contained in the garage and the route out usable.
Two extra garage requirements catch people out. Anywhere a vehicle could strike the battery, it needs impact protection to IK10 or a physical barrier that does the same job. An attached garage also needs fresh-air ventilation to outside. The battery’s own enclosure has to be non-combustible, and the unit still has to sit inside its rated temperature range, which matters because garages run cold and damp in winter.
Can a battery be installed outside?
Yes, and outdoors is where PAS 63100 tells installers to put the battery where practicable, because keeping it off the living space lowers the risk to the people inside. An external wall mount or a ground enclosure holds a fire outside the occupied rooms. The conditions are a weatherproof enclosure rated for the job, a position at least 1 metre from any window, door, vent or escape route, at least 2 metres from stored fuel or flammable materials, and clear of any credible flood line.
An external-wall mount is still fixed to the building, so it is not risk-free. PAS 63100 requires the installation to keep the wall’s fire performance intact: any holes made for cables are fire-stopped, combustible material behind the unit is not left exposed, and cavity barriers are kept in place where the wall has a cavity. A good installer treats the wall as part of the fire design, not just a fixing point.
The honest trade-off outdoors is temperature. Lithium batteries lose usable capacity in the cold and many will not charge at full rate near freezing, so a unit on a north-facing wall through a UK winter can behave differently from the datasheet figure measured at 25 degrees. Check the manufacturer’s rated operating and charging window for your exact model and confirm the spot stays inside it all year. Some outdoor-rated units add heaters or a wider temperature tolerance for this reason.
Flood risk is the other outdoor factor to weigh. If your property sits in a flood-risk area, a ground enclosure at low level is the wrong choice. Raise it, or mount on a wall above any credible flood line.
Utility rooms, cupboards, hallways and bedrooms
Indoors works only in the right kind of room. A utility or plant room can take a battery if fire-resisting construction of at least about 30 minutes (REI 30) separates it from sleeping rooms and escape routes, it has fresh-air ventilation to outside, and it has interlinked fire detection. Those three conditions are the test, and a quote that skips any of them is not compliant.
Two indoor locations are off the list outright. A battery must not go in a bedroom or any room used for sleeping, nor in a cupboard that opens into one, because a fire or its smoke would reach sleepers first. It must not go on a hallway, staircase or landing that forms an escape route, and PAS 63100 bans that whether the route is a protected fire-rated one or an ordinary one, because a battery fire there could block the way out.
That does not ban every cupboard, but it rules out the two spots people suggest most, the spare-room corner and the under-stairs cupboard off the hallway. A cupboard away from bedrooms and clear of the escape route can in principle hold a battery, but only if it still meets the same rules: fresh-air ventilation to outside, fire-resisting separation, and detection. A sealed under-stairs cupboard fails on the ventilation rule alone, which is why it so rarely works.
Fire detection has two levels worth knowing. In an infrequently visited location such as a store cupboard, PAS 63100 makes an interlinked smoke or multi-sensor alarm mandatory. More broadly, it recommends that any home with a battery has fire detection to at least Grade D2, Category LD2, which is the spec to quote back to an installer. Detection is easy to leave out of a quote, so confirm it is in the design.
Already have a battery in the wrong place?
The 15 October 2026 date is a deadline for new work, not a retrofit order. Neither PAS 63100 nor BS 7671 is applied retrospectively, so a battery installed to the rules in force at the time does not automatically have to be moved. If yours was signed off correctly, it stays valid.
A genuinely unsafe location is a different matter. A battery in a loft, a bedroom or across an escape route is a safety problem regardless of when it went in, and it is worth raising with a competent installer and with your insurer rather than leaving it. Moving a commissioned battery means disconnecting a live unit, remounting it and further electrical work, so price that in, but treat a dangerous position as worth undoing.
What to demand from your installer before you sign
The location is the one part of a battery quote where a homeowner can hold an installer to a written standard. Ask for these, on the quote, before you commit:
- The exact room or wall the battery will sit on, and a plain statement of why it complies with PAS 63100 and BS 7671 Chapter 57.
- For any indoor position, the fire separation being provided, in minutes, and the interlinked fire detection being added.
- Confirmation the location has fresh-air ventilation to outside and is not a sealed cupboard.
- The clearances measured: at least 1 metre from windows, doors, vents and escape routes, and at least 2 metres from stored fuel or flammables.
- The manufacturer’s own siting and temperature limits for your specific model, and confirmation the spot stays inside them all year.
- The paperwork you will receive: a BS 7671 Electrical Installation Certificate, the DNO notification under G98 or G99, MCS documentation if the installer is MCS-certified, and whatever building regulations require where you live.
If an installer cannot say where the battery goes and why it complies, that is the answer. PAS 63100 is free to read, so you can check any claim against clauses 6.5.1 to 6.5.7 yourself. The location is not a detail to leave to whoever turns up on the day.
Insurance, warranty and building control
A non-compliant battery location does not usually make you a criminal, but it puts three things at risk. A manufacturer can decline a warranty claim if the unit was installed outside its stated conditions. A home insurer can question a fire claim if the installation did not meet the recognised standard. And because BS 7671 is the standard building control and MCS certification work to, a battery placed against Chapter 57 once it is the current edition is not a job a compliant installer can sign off.
Warranty and insurance terms are specific to your product and your policy, so check them rather than assume. It is worth asking your home insurer whether they need to be told you have a battery and where it sits. That is a cheap question now against an expensive argument after a claim.
The next move
Walk your house with the six questions in mind: escape route, fire separation, ventilation, temperature, flood and access. In most UK homes that points at an outside wall, a garage, or a properly separated utility room, and away from the loft, the bedrooms and the hallway. Download PAS 63100 free from BSI so you can quote it back, then make your installer put the location and its justification in writing before you sign.
Get the position right first and everything downstream, from the wiring certificate to the insurance line to how the battery performs next January, gets easier.
Sources
- BSI, PAS 63100:2024 Electrical installations. Protection against fire of battery energy storage systems for use in dwellings. Specification (published 20 March 2024, free to download). Prohibited locations, clearances and separation ratings are in clauses 6.5.1 to 6.5.7.
- IET, BS 7671:2018+A4:2026 (Amendment 4) and its new Chapter 57 on stationary secondary battery installations (published 15 April 2026, previous edition withdrawn 15 October 2026).
- MCS, Battery Installation Standard (MIS 3012:2025), the certification standard for MCS-registered battery installs.
- MCS, Update on PAS 63100 and the IET Code of Practice for Electrical Energy Storage Systems, on how PAS 63100 applies to certified installs.
