Direct answer: Since 27 August 2026 plug-in solar has its own permitted development rights in England — and its own prohibitions. Here is what the General Permitted Development Order actually allows, wall by wall.
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Where a Plug-in Solar Kit Can Legally Go: Planning Permission and Prohibited Surfaces
There are two separate questions about where a plug-in kit can go, and they are decided by different documents. Planning law says whether you are allowed to put panels there at all. The product specification says which surfaces a compliant kit may be installed on, for fire safety. A wall can pass one test and fail the other.
Planning: the new permitted development right
Solar panels on domestic premises have long been permitted development under Class A of Part 14 of the Town and Country Planning (General Permitted Development) (England) Order 2015. On 27 August 2026 the General Permitted Development) (England) (Amendment) Order 2026 (S.I. 2026/896) rewrote Class A and Class B so that they name plug-in solar explicitly.
Class A covers equipment installed on a building — a wall, a roof, a balcony enclosure. Class B covers stand-alone equipment within the curtilage, which is where a ground-mounted frame in a garden or yard falls.
Both are permitted development, which means no planning application, provided the conditions in the Order are met. The conditions are not optional: breaching one takes the installation outside the permission.
The limits for equipment on a building (Class A)
The Order sets different limits for a house and for a block of flats.
On a house, development is not permitted if the equipment:
- protrudes more than 0.2 m beyond the plane of a wall that abuts a highway, or 0.4 m beyond any other wall;
- protrudes more than 0.2 m beyond a balcony enclosure or roof enclosure that abuts a highway, or 0.4 m beyond any other enclosure;
- on a pitched roof, protrudes more than 0.2 m beyond the roof slope or reaches above the ridge;
- on a flat roof, rises more than 0.6 m above the highest part of the roof;
- goes on a wall, balcony or roof enclosure that fronts a highway in a conservation area or World Heritage Site;
- goes on a scheduled monument, or on a listed building.
On a block of flats, the protrusion limit is 0.2 m throughout, and the same conservation-area, scheduled-monument and listed-building restrictions apply — with the listed-building bar covering the whole block, not just your flat.
Timber is prohibited outright. For plug-in solar, development is not permitted where any part of the kit would be installed on a wooden wall, balcony or enclosure, or on any part of the exterior of a house or block of flats that is clad in timber.
That timber bar is the single most common trip hazard for balcony installations, because a great many UK balconies are timber-decked or timber-screened. A metal railing with a timber privacy screen counts: the screen is part of the enclosure the panels would be fixed to.
Stand-alone kits in the garden (Class B)
A ground-mounted frame is permitted development within the curtilage, subject to:
- one stand-alone solar installation in the curtilage;
- panel surface area no more than 9 m², and no dimension of the array — including its housing — longer than 3 m;
- height limits that depend on position: 1 m where the array is within 5 m of the boundary and forward of the principal elevation; 2 m where it is within 5 m of the boundary; 2 m in a conservation area where it sits nearer to a highway than the house does; 4 m otherwise;
- not within the curtilage of a listed building, on a scheduled monument, or — for plug-in solar — on a wooden fence, gate, wall or other means of enclosure.
That last line rules out the cheapest mounting trick there is: hanging panels on a timber fence.
What the product specification adds
Planning permission is not the only gate. Section 5.8 of the Plug-in Solar Device Interim Product Specification, version 2 states that installations are not permitted on:
- aluminium composite material (ACM) or metal composite material (MCM) cladding systems;
- high pressure laminate (HPL) cladding systems;
- timber cladding systems;
- timber balconies;
- buildings subject to external wall remediation works, building safety remediation works, or equivalent restrictions relating to external wall fire safety.
The specification also requires the manufacturer to identify any planning restrictions on installation surfaces or building types that apply to their product, and to include those in the installation instructions. If the instructions do not mention the surface you have in mind, that is a question worth putting to the manufacturer before you buy.
Flats, leaseholds and rented homes
Planning permission and permission to install are different things. If you rent, the tenancy agreement governs; written permission from the landlord is the safe position whatever the planning rules say. If you own a leasehold flat, the lease usually controls alterations to the exterior and the common parts, and a balcony railing is often common property — so the freeholder or managing agent needs to be asked, not told.
Where the block is listed, permitted development does not apply at all, and an application is the only route.
What this means in practice
- A rendered brick or masonry wall on a house, within 0.4 m of protrusion and not fronting a highway in a conservation area: permitted development, and allowed by the specification.
- A metal balcony railing with panels clamped to it, on a modern block: permitted development within the 0.2 m limit, subject to the lease.
- A timber balcony, or panels screwed to a timber fence: not permitted, regardless of the kit.
- A garden frame within 5 m of the boundary: permitted, but keep the top of the array at or below 2 m.
- A building wrapped in ACM cladding or awaiting remediation: not permitted, whatever the planning position.
Sources and limits
- The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 14 — Class A and Class B as amended on 27 August 2026.
- The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2026, S.I. 2026/896.
- Plug-in Solar Device Interim Product Specification, version 2, section 5.8.
This covers England. Scotland, Wales and Northern Ireland have their own permitted development regimes, and the plug-in solar safety regulations apply across Great Britain. Planning law is fact-specific: a conservation area boundary, an article 4 direction or a listed building changes the answer, and a local planning authority is the authority on its own area.