Solar panels on a house: limits and listed buildings

Solar panels on a house usually need no planning permission, because Class A of Schedule 2, Part 14 to the General Permitted Development Order 2015 covers roof-mounted solar photovoltaic and solar thermal equipment on a dwellinghouse. Two numbers do most of the work: the equipment must not stick out more than 0.2 metres from the roof slope or wall, and no part of it may sit higher than the highest part of the roof, chimneys excluded. Listed buildings are the exception that catches people out, and it is a serious one.

Everything below assumes England. Check whether an Article 4 direction applies to your street before relying on any of it, because those directions remove permitted development rights and they are common in conservation areas.

What Class A of Part 14 permits

Class A covers installing, altering or replacing solar equipment on a dwellinghouse or a block of flats, and on a building within the curtilage of one. That last limb is what lets panels go on a detached garage roof.

The Order has been amended more than once to widen solar rights, so work from the current text rather than a guide written a few years ago. The limits that have stayed constant are the ones below.

Flats need care. The right applies to the block, and the person with the legal ability to install on a shared roof is usually the freeholder rather than a leaseholder, which is a different obstacle from planning but just as final. The same split between the building and the individual unit is what makes householder rights inapplicable to flats for extensions.

The 0.2 metre projection and the ridge line

Measure the projection at right angles to the surface the panels sit on, not vertically. On a pitched roof, panels on standard rails sit comfortably inside 0.2 metres, so the limit rarely bites.

Flat roofs are the problem. A tilted frame that lifts panels to 20 or 30 degrees for better yield almost always projects more than 0.2 metres above the roof surface, which takes the installation outside Class A. Options are to lay panels close to flat and accept the lower output, or to apply for planning permission. Plenty of councils grant it on a flat roof that is not visible from the street.

The ridge rule is simpler. Nothing may rise above the highest part of the roof. Chimneys do not count as part of the roof for this purpose, so a panel cannot be justified by reference to a chimney stack.

Siting to minimise the effect on appearance

The siting requirement in Class A is a condition, not advice. Panels must be positioned, so far as practicable, to minimise the effect on the external appearance of the building and on the amenity of the area.

In practice that means choosing the rear or a side slope over the front where the yield difference is tolerable, keeping the array as a single rectangle rather than scattering panels around rooflights, aligning the edges with the roof edges, and using all-black panels with black frames on a slate roof. None of that is legally prescribed. All of it reduces the chance of an enforcement enquiry, because the complaint that triggers one is almost always about appearance.

Where the array cannot avoid a prominent slope, take a photograph of the proposed layout overlaid on the elevation before ordering. It costs nothing and it settles most neighbour arguments before they start.

Conservation areas and walls fronting a highway

In a conservation area or a World Heritage Site, Class A does not permit solar equipment on a wall which fronts a highway. Note the wording: a wall, not a roof. Roof-mounted panels on a front roof slope in a conservation area are not excluded by that limb, although the siting condition still applies and an Article 4 direction may have removed the right altogether.

Article 4 directions are the real variable. Many councils have made them over conservation areas, and their scope differs from one authority to the next. Check the council's Article 4 register or ask before you order equipment, using the same discipline set out for replacement windows in an Article 4 area.

If permission does turn out to be needed, a short Planning Statement explaining the energy case, the siting alternatives considered and the visual effect usually carries a householder application without further documents.

Listed buildings and the separate consent

This is the part that goes wrong most often. Permitted development rights and listed building consent are separate regimes, and satisfying one does nothing for the other.

Works to a listed building which affect its character as a building of special architectural or historic interest need listed building consent under section 7 of the Planning (Listed Buildings and Conservation Areas) Act 1990. Carrying out those works without consent is a criminal offence, not merely a breach of planning control, and there is no time limit that makes it lawful later. Fixing panels through a historic roof covering, adding rails to a listed roof, or running cabling through historic fabric all fall within that.

Consent is not automatic and it is not impossible either. Applications succeed more often where the array sits on a later, lower or rear roof slope, on an outbuilding within the curtilage, or on a ground mounted frame away from the main house. Reversibility helps: fixings into existing batten lines rather than through historic timbers, and a cable route that can be removed without trace.

A Heritage Statement setting out the significance of the building, the effect of the proposal and the alternatives considered is the document that decides these applications. Historic England publishes advice on energy efficiency and renewables in historic buildings, and quoting it accurately is worth more than any amount of argument about carbon.

Ground mounted arrays under Class B

Class B of Part 14 covers standalone solar within the curtilage of a dwellinghouse, and the limits are tighter than most people expect. Only one standalone installation is permitted. It must not exceed 4 metres in height, must not sit within 5 metres of the boundary of the curtilage, and the panel surface area must not exceed 9 m², with no dimension of the array including its housing exceeding 3 metres.

Class B does not apply within the curtilage of a listed building at all. In a conservation area or World Heritage Site, a standalone installation must not be visible from the highway.

Nine square metres is roughly four or five domestic panels. Anyone planning a meaningful ground array on a large garden is applying for planning permission, and should budget for a design that is screened from public view.

Removal when no longer needed

Both classes carry a condition requiring the equipment to be removed as soon as reasonably practicable when it is no longer needed. Dead panels left on a roof for years are a breach of condition, and they are one of the few solar issues that generates enforcement action.

Keep the installation paperwork with the house deeds. A buyer's solicitor will ask, and an installation certificate plus a note of the roof slope and array dimensions answers the question in one page.

To see which documents a project is likely to need if permission turns out to be required, enter your postcode on PlanScope and answer the guided questions.

This is general guidance, not legal advice, so check the position with your local planning authority or a qualified professional before relying on it. A Lawful Development Certificate is the only formal way to confirm that works are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.