Can I Put a Skylight in My House Without Planning Permission?

Usually, yes — most skylights in UK houses don’t need planning permission. Roof windows fall under permitted development provided they meet a short list of conditions. But “usually” hides three traps — flats, conservation areas and building regulations — that catch people every year. Here’s the full picture.

The permitted development rules for skylights

Under permitted development (Schedule 2, Part 1, Class C of the GPDO — alterations to a roof), a skylight needs all of the following to be true, per the government’s technical guidance for householders:

1. It projects no more than 150mm beyond the plane of the existing roof slope, measured perpendicular to the roof surface. Modern low-profile roof windows and conservation-style units meet this comfortably; chunky older-style dome rooflights on upstands sometimes don’t.
2. It sits no higher than the highest part of the roof (the ridge, on a pitched roof).
3. Side-facing windows are obscure-glazed, and non-opening unless the opening part is more than 1.7 metres above the floor of the room.

Meet all three in an ordinary house and you can fit the skylight without a planning application — whether it’s a VELUX, a Fakro or any other brand; the rules are about the opening, not the logo.

The exceptions that catch people out

• Flats and maisonettes. These householder permitted development rights apply to houses only. In a flat you’ll generally need planning permission — and your lease almost certainly requires the freeholder’s consent too.
• Listed buildings. You need listed building consent for alterations affecting character — effectively always, for a new roof window. Skipping this is a criminal offence, not just a planning breach.
• Conservation areas and Article 4 directions. Class C technically still applies in conservation areas, but many councils remove those rights with an Article 4 direction, and front-elevation rooflights attract attention. A quick call to the local planning authority settles it.
• Homes with conditions attached. New-build estates sometimes have permitted development rights removed by the original planning consent. Check your property’s planning history if the house is recent.

If you’re near any of these lines, a Lawful Development Certificate is the belt-and-braces option: a formal council determination that your skylight is lawful, for a modest fee (current fees are on the Planning Portal). Solicitors ask for these when you sell.

Building regulations: the approval you always need

Planning permission and building regulations are separate systems, and skylights always involve building regs, because a new opening:

• Alters the roof structure — rafters are cut and trimmed, and the work must prove structural adequacy;
• Changes thermal performance — the window must meet current Part L standards for glazing;
• May serve as a fire escape — loft-conversion windows have minimum opening sizes and sill-height rules.

In practice this is painless: use an installer registered with a competent person scheme (such as FENSA or CERTASS) and they self-certify the work and lodge the certificate — no separate building control application. Fitting it yourself or using an unregistered builder means a building control application and inspection instead. Either way, keep the paperwork; buyers’ solicitors ask.

Practical order of operations

1. Check the three permitted development conditions above against your roof and window choice.
2. If you’re in a flat, listed building or conservation area — talk to the council before ordering anything.
3. Choose the window and budget realistically — permission is rarely the expensive part.
4. Use a competent-person-scheme installer so building regs are handled for you.
5. File every certificate with your deeds.

The rules above are the position in England as of July 2026 — Wales, Scotland and Northern Ireland have their own variations of permitted development, so check the national guidance if you’re outside England. When in doubt, twenty minutes with your local planning authority is cheaper than moving a window.