Solar panels under permitted development or an application

Most roof mounted domestic solar in England goes ahead without a planning application, under Schedule 2 Part 14 of the Town and Country Planning (General Permitted Development) (England) Order 2015. The solar panel permitted development limits that matter are simple to state: the panels must not stand more than 0.2 metres out from the roof slope or wall when measured perpendicularly, and they must not sit higher than the highest part of the roof, ignoring the chimney. Break either and you need permission.

The complications come from where the building is rather than what the panels are. A conservation area, a World Heritage Site, a listed building or a scheduled monument each changes the answer, and so does an Article 4 direction.

The limits on roof mounted panels

Part 14 Class A covers solar photovoltaic and solar thermal equipment on a dwellinghouse, or on a building inside its curtilage such as a garage or outbuilding. The restrictions are the ones to memorise.

The 0.2 m figure is the one that catches flat roofs. A ballasted frame tilted to 10 or 15 degrees on a flat garage roof will almost always stand more than 200 mm above the roof surface, so a flat roof array is frequently an application even though the same panels on a pitched roof next door are not.

Class A also carries conditions rather than limits. So far as practicable the equipment has to be sited to minimise its effect on the external appearance of the building and on the amenity of the area, and it has to be removed as soon as reasonably practicable once it is no longer needed for microgeneration. Those conditions are enforceable, and an installer who puts an array on the front slope facing a street when the rear slope had the same orientation has arguably breached the first of them.

Part 14 has been amended more than once since 2015. Read the consolidated text on legislation.gov.uk on the day you rely on it rather than a printout from a year ago.

Standalone arrays and their separate limits

Ground mounted solar in a domestic garden falls under Class B, which is considerably tighter. One standalone installation only. Height not more than 4 metres. Nothing within 5 metres of the boundary of the curtilage. Panel surface area not more than 9 m2, and no single dimension of the array, including its housing, more than 3 metres.

In a conservation area or World Heritage Site the array must not be visible from a highway. That is a practical test, judged from the road, and a hedge that is currently 2 metres tall is not a permanent answer.

Nine square metres is roughly 4 to 5 standard panels. Anyone planning a ground array sized for a heat pump and an electric car is going to exceed it, which means an application.

Conservation areas, listed buildings and world heritage sites

Listed buildings are the sharpest trap. Part 14 does not remove the need for listed building consent, and fixing panels to the roof of a listed building involves works affecting its character as a building of special architectural or historic interest. Consent is required under the Planning (Listed Buildings and Conservation Areas) Act 1990 whether or not planning permission is also needed, and carrying out the works without it is a criminal offence.

In practice, listed building applications for solar succeed more often on rear slopes hidden from public view, on outbuildings, and on ground arrays screened by existing planting. They succeed less often on a principal elevation, on plain clay pantile or stone slate roofs where fixings damage historic fabric, and where the array reads as a modern band across a roof visible from the churchyard. Historic England's technical advice on energy efficiency in historic buildings sets out the reasoning that conservation officers apply.

A Heritage Statement is the document that carries the argument. It should describe the significance of the building, identify what the array touches, and explain the alternatives you considered and rejected. Councils in conservation areas frequently refuse solar applications that arrive with a product brochure and no assessment of significance at all.

Flats and non-domestic buildings

The GPDO's definition of a dwellinghouse excludes a building containing flats and a flat within such a building, so a leaseholder cannot assume Class A applies to the roof above them. There are separate classes in Part 14 for solar on non-domestic buildings and for standalone arrays on non-domestic land, with their own limits, and the current text should be checked directly.

For a flat there is usually a prior question anyway. The roof is normally retained by the freeholder, so the lease and the freeholder's consent come before the planning analysis. Plenty of schemes die at that stage without a planning officer ever seeing them.

Siting conditions on visual amenity

The amenity conditions in Class A are where disputes actually happen. A neighbour complaint about glare or about a front-facing array will be assessed against whether the siting minimised the effect on the appearance of the building so far as practicable, and that is a question of fact.

Two habits reduce the risk. Photograph the roof from the street before installation, and keep the installer's written note of why the chosen slope was selected over the alternatives. Both cost nothing at the time and are awkward to reconstruct two years later.

When permission is needed

A householder application is the route where any limit is exceeded. It is a full application in procedural terms, determined in eight weeks for a minor development, and the council will want a location plan, a block plan, elevations showing the array, and a short statement. Where the building is listed, a listed building consent application runs alongside it, and there is no fee for listed building consent.

If the panels are being added to a scheme that already has permission, check whether a variation is a cleaner route than a fresh application. Our comparison of section 73 against section 96A explains which mechanism fits which kind of change. And if an application is refused, the householder appeal route has a 12 week timetable and no need for a full statement of case.

A short Planning Statement is worth including even on a householder application for solar, because it lets you put the national policy support for renewable energy and the local design policy in the same document the case officer reads first.

Recording the position

Permitted development is a legal conclusion you reach yourself, and the council is not bound by your view of it. The only formal way to confirm that works are lawful is a Lawful Development Certificate under section 192 of the Town and Country Planning Act 1990 for proposed works, or section 191 for work already done. It costs a fee and takes eight weeks, and for a straightforward pitched roof array most people reasonably decide not to bother.

Bother when the position is arguable. Flat roof mountings, arrays on outbuildings near a boundary, anything in a conservation area, and any property where an Article 4 direction might have withdrawn Part 14 rights. Ask the council's planning department in writing whether an Article 4 direction applies to the address before you order the panels, because that single question resolves a large share of the genuine disputes.

Keep the manufacturer's data sheet, the installer's siting note, the photographs and any council correspondence in one folder. If a purchaser's solicitor asks in six years, that folder is the answer.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. Enter your postcode on PlanScope to see which reports your site is likely to need. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.