Flat rooflights for Swanley: the essentials
Our flat rooflights service in Swanley covers fixed double or triple glazed rooflights for flat roofs and extensions. Every job starts with a survey of the opening, the roof covering and the room below, and a fixed written price.
Larger gardens in much of the South East mean deeper rear extensions, and deeper rooms need light from above rather than only from the doors. In Swanley, as anywhere, flat rooflights are the usual choice for landings, bathrooms and rear extensions with flat roofs.
Jobs in Swanley are planned around access: whether the roof can be reached from the garden, whether a hoist or crane is needed, and where we can park. We check this when we measure.
What you can choose
- Frame colours: anthracite, black, white or RAL
- Double or triple glazing
- Solar-control or self-cleaning outer pane
- Square, rectangular or long-format sizes
- Insulated kerb or timber upstand built to suit
- Slim sightlines from inside — mostly glass, little frame
- Pairs with an opening unit where you also need ventilation
What to check first
- New openings in an existing roof need a structural check on joists
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
Planning and building rules for Swanley
Most rooflights on English houses do not need planning permission, provided they keep within 150 mm of the roof surface and below the ridge line. Listed buildings need listed building consent, flats have no householder permitted development rights, and an Article 4 direction can remove the rights in some conservation areas.
Building Regulations Approved Document L sets a limiting U-value of 2.2 W/m²K for new or replacement rooflights in existing homes, measured in the horizontal plane; roof windows need 1.4 W/m²K or a Band B energy rating. The Future Homes and Buildings Standards, published in March 2026, apply from 24 March 2027 and keep the 2.2 W/m²K limit for rooflights.
See our building regulations guide for U-values, glazing limits and self-certification.
Guide prices for Swanley
The ranges below are typical for straightforward jobs; your fixed price follows a survey of your roof.
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Large or triple glazed (1500 × 2500 mm and up) | £2,395 – £4,195 | £1,995 – £3,495 |
| Mid-size double glazed (1000 × 2000 mm) Typical | £1,675 – £2,395 | £1,395 – £1,995 |
| Small double glazed (up to 1000 × 1000 mm) | £1,195 – £1,795 | £995 – £1,495 |
From enquiry to finished job
- Get in touch. Use the form, WhatsApp or the guide-price tool with your Swanley address.
- Free site visit. For new installs we survey free, measure and confirm the roof detail.
- Agree the quote. You approve the specification and price before anything is ordered.
- Installation day. Usually one day into a prepared opening, longer for new openings.
Nearby towns
Other services in Swanley
Common questions
Double or triple glazing?
Double glazing suits most domestic jobs. Triple glazing improves thermal performance and cuts noise from rain, which is worth it over bedrooms or where the energy calculation is tight.
Will it make the room too hot?
A big unglazed-to-sky area can add solar gain in summer. Solar-control glass, a blind, or pairing a fixed unit with an opening one keeps it comfortable.
Do flat rooflights leak?
A well-fitted flat rooflight should not leak. Leaks almost always come from the upstand or membrane detailing, not the glass unit, which is why the upstand height and the way the roof covering is dressed up and under the frame matter more than the brand.
Will I need planning permission in Swanley?
In England a rooflight on a house is usually permitted development under Class C if it projects no more than 150 mm beyond the roof slope and sits no higher than the ridge.
Is the survey in Swanley free?
Yes for new installations. Repair visits are charged, and we tell you the price before we book.
