Solar planning permission in Wales

Many solar panel installations on Welsh homes need no planning application. However, the rules have limits and exceptions, so it pays to check before you sign a contract. This guide sets out the main tests for homes. It then covers listed buildings, conservation areas, national parks and ground arrays.

Solar Cymru is an independent guide and not a planning authority. Your council has the final word on your property.

The common limits

Fixing panels to the roof of a single house is in many cases permitted development. Planning permission is therefore often not needed. The legal tests come from the Welsh planning rules, and the Welsh Government explains them on its solar planning page.

Roof and wall panels must not stick out more than 200 mm from the plane of the wall or roof slope. They must not stand higher than the highest part of the roof, not counting any chimney. As far as practicable, you must also site them to limit the effect on the building and the area. You must remove them when you no longer need them to make power.

Flat roofs

Flat roofs are inside the rules, although they have their own limits. Panels must sit at least 1 m from the outer edge of the roof. They must not rise more than 1 m above the plane of the roof.

Where the rules tighten

Some properties sit outside the simple tests. In a conservation area or a World Heritage Site, panels on a wall that faces a highway need planning permission. This covers the main or side wall of the house, and walls of buildings in the garden. However, the wall rule does not by itself cover roof slopes, so still check for an Article 4 direction.

A listed building is different, because permitted development does not apply. Panels on a listed house, or on a building in its grounds, need planning permission. Listed building consent is likely too. Cadw says an application can require a heritage impact statement. Our post on solar panels on listed buildings and in conservation areas goes through the process.

Panels on a scheduled monument also fall outside the rules. Separately, a council can remove these rights through an Article 4 direction, which is common in conservation areas. It can also do so through a condition on the original planning permission. The council’s planning register shows whether this applies to you.

National parks

Bannau Brycheiniog, Pembrokeshire Coast and Eryri have their own national park authorities. The Welsh domestic solar rules name conservation areas and World Heritage Sites, not national parks. Even so, ask the authority or your council before you commit, because local designations can change the answer.

Business and farm buildings follow different rules, and those do name national parks. Our post on solar panels in Wales’s national parks explains the difference.

Slate roofs and structure

Planning is separate from the roof itself. Building Regulations normally apply to solar on a roof, so the installer must check and prove that the roof can carry the load. MCS says brackets on slate or tiled roofs must not load the slates unless a certified bracket spreads the load. Our post on fitting solar panels on a Welsh slate roof covers the detail.

Flats and leasehold homes

The rules for solar apply to houses. If you live in a flat, ask your local planning authority what applies. A leaseholder may also need permission from the landlord, freeholder or management company.

Ground-mounted solar in a garden

A stand-alone array in a house garden counts as permitted development only if it meets every test. You can have only one array. No part may stand above 4 m, and any part within 5 m of the boundary may rise no higher than 2 m. It must sit at least 5 m from the highway. No side may exceed 3 m, and the panel surface may measure no more than 9 square metres.

The array must also stay out of the grounds of a listed building. In a conservation area or World Heritage Site, it cannot sit between the highway and the house. Larger arrays need an application. Our post on ground-mounted solar and planning in Wales looks at the next steps.

Businesses, farms and community buildings

Roof solar on a business, farm or community building in Wales needs no application if the conditions are met. There is no kilowatt cap, because the old 50 kW figure is out of date. Our page on commercial solar in Wales covers the conditions.

How to check with your council

Start with the official guidance, then confirm any doubtful point with the local planning authority. Ask whether an Article 4 direction or a planning condition removed your rights. Get the answer in writing before work starts.

Your installer should also know the local picture. For example, our page on solar installers in Cardiff shows the council details for one city. When you are ready, use our get quotes page to ask MCS-certified installers for a quote.