In brief
It depends on where the lantern goes. A lantern on an extension that is being built is part of that extension, so it is covered by the extension's planning permission or its permitted development rights. A lantern added to an existing roof falls under the rules for rooflights on that house. The position at your address is looked up by us and reported back, and the council decides.
- On a new extension, the lantern is part of the extension's own permission
- On an existing roof, the permitted development rules for rooflights apply
- Listed buildings, conservation areas and Article 4 directions change the answer
- A planning condition on your house can remove permitted development
- The council gives the answer, and a lawful development certificate can confirm it
A lantern on an extension that is being built
When a flat-roofed extension is designed with a lantern, the lantern is drawn into the scheme. If the extension goes through a planning application, the lantern is on the approved drawings, and the roof as shown is what the council has agreed. If the extension is built under permitted development, the lantern is part of the roof the rules were applied to.
For that reason, the best moment to settle a lantern is at design stage, before the application or the notification. The architect can draw it with its true height and footprint, and the council sees the whole roof at once. Adding a lantern after approval can mean going back to the council for an amendment.
Extensions have their own limits on height, depth and position, and a lantern rising above a flat roof adds to the overall height. Your architect or planning consultant checks that the extension plus lantern stays within whatever route has been chosen.
A lantern on an existing roof
Where a lantern is added to a roof that already exists, it is judged as a change to the house. Many rooflight changes can be made under permitted development, which is set out in Class C of Part 1, Schedule 2 of the General Permitted Development Order. Our guide to rooflight planning permission and permitted development lists the conditions in full, so they are not repeated here.
A lantern stands up from the roof more than a flat rooflight does, and that is the point to look at closely. Because the conditions limit how far a rooflight may project from the roof and how high it may rise, a lantern needs a careful check against them before it is ordered. A low-profile flat rooflight may sit within the limits where a tall lantern does not.
If the lantern would not fit within the permitted development limits, a planning application is the route, and the council decides it on its merits.
What can remove permitted development
Permitted development is a default that can be taken away. It does not apply to listed buildings, which need listed building consent for changes that affect their character. It can be withdrawn by an Article 4 direction, which a council makes for a defined area, commonly a conservation area. It can also be removed by a condition on the original planning permission, which is often attached to newer estates.
Land inside a National Park has reduced permitted development rights, so the check matters more there. In our area that means the New Forest National Park Authority or the South Downs National Park Authority, depending on the address, and each is the planning authority for land inside its boundary.
None of these is guessed at. You are shown how to check each one for your address, and where the answer stays unclear, the council is the body to ask. Putting the question in writing and keeping the reply gives your builder something firm to work from, and gives the architect a record to attach to the drawings.
How to check your own address
- Find your council's planning pages and look for any Article 4 direction that covers your street.
- Read the decision notice for your house, or for the estate, for conditions that remove permitted development.
- Check whether the house is listed or in a conservation area through the council or Historic England.
- Ask the council, or use the Planning Portal, if a lantern or rooflight is something you can do without an application.
The Planning Portal explains the application routes and has an interactive guide to permitted development. If you want written certainty, you can apply to the council for a lawful development certificate, which confirms that the proposal is lawful for planning purposes.
Planning and Building Regulations are separate
A lantern may need no planning application and still be subject to Building Regulations, which cover structure, thermal performance and safety. The two systems are separate, and satisfying one does not satisfy the other. We fit rooflights to current requirements, and where the job is notifiable, the Building Control notice is sent by us before work starts, so the sign-off is not left to the end.
Part L sets performance limits that apply to rooflights in existing homes, and the glazing named in your quote is chosen to meet them. Our guide to Building Regulations for skylights and rooflights covers the detail.
What we do before you order
At the survey we note the roof, the lantern height you are considering and anything that suggests a restriction, such as a conservation area or a listed neighbour. We tell you what the checks suggest, and recommend whether to ask the council before ordering.
A lantern is made to measure, so it should not be ordered until the position is settled, because a unit already in production is hard to change. We can then give the builder the kerb sizes in writing and place the order against the programme. If you are weighing a lantern against a flat rooflight, which sits lower, read our comparison of a roof lantern or a flat rooflight. For the other half of the project, see how we handle roof lantern installation, and for the price, what a lantern costs to fit.
