Do conservation rooflights need planning permission?

For a dwelling house, the General Permitted Development Order deals with rooflights under Class C, in Part 1 of Schedule 2. It sets out three limits. Nothing may stand more than 150mm out from the existing roof slope. Nothing may rise above the roof's highest point. And in a side-facing slope the glass has to be obscure and the unit fixed, unless its opening section is over 1.7m above floor level.

Conservation rooflights are made to sit low for exactly this reason. Their frames are slim and set nearly flush with the slates or tiles, so they meet the 150mm limit comfortably. That is a point in their favour even before heritage comes into it.

A conservation area does not by itself stop you fitting a rooflight. Class C still applies in most of them. The catch is the Article 4 direction, which a council can make to withdraw permitted development rights in an area, usually for the roof slope facing a street. Where one is in force, a rooflight on that slope needs planning permission even though the same rooflight elsewhere would not.

So the answer in a conservation area is to check, not to assume. Your local planning authority can tell you whether an Article 4 direction covers your street. In Devon, that means Exeter City Council in the city and Topsham, East Devon District Council for the coast and the Otter valley, and the relevant district council elsewhere. Our guide to conservation rooflights in Devon conservation areas goes through how this plays out in practice.

A listed building is a different case. Any alteration that affects its character, which includes cutting a hole in a roof, needs listed building consent. That is separate from planning permission, and permitted development rights do not remove the need for it. Doing the work without consent is a criminal offence, and the responsibility sits with the owner, not the installer.

Consent applications are judged on how the proposal affects the building's significance. Slim, flush, traditional-looking rooflights stand a better chance than modern domes, which is partly why the conservation type exists. Where the roof is slate, the position on the slope, the size and the way the flashing is dressed all count. Our guide to conservation rooflights for listed buildings covers what the application usually needs to show.

Dartmoor and Exmoor are national parks, which are classed as Article 2(3) land. Some permitted development rights are restricted there, and the planning authority is the national park authority, not the district council. Many homes on the moorland edge sit close to the boundary, so check where the line falls for your address instead of guessing. Our answer on rooflights in Dartmoor National Park goes into this.

Householder permitted development rights are not available to flats and maisonettes. A rooflight in the flat roof of a flat, or in a converted house split into units, generally needs planning permission, and the lease may need the freeholder's agreement too. A building with a planning condition removing permitted development, which is common on newer estates, is another case where the usual rights may not apply.

If an application is needed, the owner submits it to the local planning authority, normally through the Planning Portal. For a simple rooflight on a house, a householder application is the usual route, with a location plan, a drawing of the roof showing the position and size of the rooflight, and a short description of the product. For a listed building, expect to add a heritage statement explaining what is significant about the building and why the new rooflight does not harm it.

Councils set their own timescales, and listed building consent can take longer than a householder application, so it is wise to settle the planning question before you agree a start date. If you are unsure whether permission is needed, you can apply for a lawful development certificate, which gives written confirmation that the work is lawful. It is a sensible step on a roof where the answer is not obvious, and it can help when you come to sell. The Planning Portal explains each route.

We can supply the product details and a scaled drawing of the rooflight for your application, and the finish schedule shows how the opening will look from inside. We do not make the application for you, since the owner is responsible for consent.

Planning permission and Building Regulations are different systems, and clearing one does not clear the other. Cutting a new rooflight into a roof that is already built is building work: the rafters are trimmed, which alters the structure, and the window must satisfy Part L on heat loss. A replacement of the full unit, frame and glass, is notifiable as well. A fresh sealed glass unit in a frame that stays put is not.

Listed buildings and conservation areas are not exempt, though the way Part L is applied to a historic building can allow some flexibility. We handle the Building Control notification as part of the job, so you do not have to arrange it yourself.

Three steps cover most situations:

1. Find out whether the building is listed, in a conservation area or in a national park. The local authority's website maps all three, and the National Heritage List for England is searchable on the Historic England site.
2. If any of those applies, ask the planning authority whether an Article 4 direction or listed building consent is relevant to your roof slope.
3. Ask us to note the planning position in your quote, along with the rooflight position, size and lining.

Our conservation rooflights page covers the products themselves. When you are ready, ask for a quote and tell us the address, so we can raise the planning question at the survey.