Solar Panel Planning Permission in Cornwall: Conservation Areas, AONB and Listed Buildings

The permitted development default

The starting point for solar panels on a house in Cornwall is permitted development — you do not need to apply for planning permission. Under Class A of Part 14 of the General Permitted Development Order (as amended in August 2026), panels on a house must not protrude more than 0.2 metres from a pitched roof slope and must not sit higher than the highest part of the roof, excluding chimneys. On a flat roof they can stand no more than 0.6 metres above the highest part of the roof. Wall-mounted panels can protrude up to 0.2 metres where the wall abuts a highway and 0.4 metres otherwise. Permitted development does not apply to a listed building.

Free-standing panels in a garden are a separate class (Class B), with a maximum panel area of 9 square metres, height limits that depend on how close the array is to the boundary and to the highway, and no permitted development within the curtilage of a listed building. Check the height limit for your chosen position before ordering a ground-mount kit.

Conservation areas

Cornwall has many conservation areas — central Truro, Penzance, the Charlestown and Falmouth harbours, many mining heritage areas and dozens of villages and town centres. The rule inside a conservation area (and a World Heritage Site) is narrower than many people expect: panels lose permitted development only if they are installed on a wall, balcony or roof enclosure which fronts a highway. Panels on a roof slope — including a street-facing slope — keep permitted development, provided they meet the height and protrusion limits above.

The condition that does bite is on flat roofs: a flat-roof array on land in a conservation area needs an application to the council for a prior approval decision before work starts. In Penzance, for example, the town's conservation area covers much of the historic centre, yet most roof-slope installations there remain permitted development — our page on solar panels in Penzance shows how that works alongside the listed buildings on Chapel Street.

Cornwall National Landscape (formerly AONB)

The Cornwall National Landscape, the area formerly called the Cornwall Area of Outstanding Natural Beauty, covers large parts of the coast and moors. For rooftop solar on a house it does not add the conservation-area wall restriction, so the general Class A limits apply. It does count as protected land for the flat-roof rule, so a flat-roof array inside the National Landscape needs a prior approval application before installation, just as it would in a conservation area.

Listed buildings

Permitted development for solar does not apply to listed buildings. Any solar installation on a listed property — regardless of which roof surface, and whether or not it is in a conservation area — requires listed building consent in addition to any planning permission. Listed building consent applications are assessed on heritage impact grounds. The key factors are visibility from public vantage points, reversibility of fixing methods, and whether the installation would harm the special interest of the building.

Cornwall has a very high density of listed buildings, particularly granite vernacular houses, mining heritage structures, and coastal properties. Our surveyors can advise on whether listed building consent is needed and what a successful application typically looks like.

Flat roofs and ground-mount

Outside protected land, flat-roof panels are permitted development if they stay within 0.6 metres of the highest part of the roof. In a conservation area, a World Heritage Site or the National Landscape, a flat-roof array needs a prior approval decision from Cornwall Council first — keeping panels below a parapet does not remove that requirement. Ground-mounted arrays in a garden follow Class B: up to 9 square metres of panels, with height limits that tighten near the boundary and near the highway, and no permitted development within the curtilage of a listed building.

Practical next steps

Our survey process includes a planning check as standard. We will advise you at the survey visit whether your installation falls within permitted development, whether a prior notification is advisable, or whether a planning application is needed. We handle planning applications on your behalf where required. There is no additional charge for the planning advice during the survey.

See our solar panel installation service or book a free survey.