How we approach flat rooflights in Coulsdon
Our flat rooflights service in Coulsdon 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.
Mansard and loft conversions are common across London, and roof windows are often set out alongside dormers on the rear slope. In Coulsdon, as anywhere, flat rooflights are the usual choice for landings, bathrooms and rear extensions with flat roofs.
Coulsdon is around 21 km from central London, and we survey and fit throughout that part of Greater London, including the CR5 district.
What you can choose
- Solar-control or self-cleaning outer pane
- Plastered or lined internal reveal
- Frame colours: anthracite, black, white or RAL
- Square, rectangular or long-format sizes
- Integral or fitted blinds
- Fixed units are simple, quiet and low-maintenance
- Even, top-down daylight across the whole room
What to check first
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
- Needs a properly formed upstand — usually at least 150 mm above the finished roof surface (check the manufacturer's figure)
Consents for flat rooflights in Coulsdon
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. 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.
Under Approved Document L, a rooflight added to an English home must achieve at least 2.2 W/m²K (horizontal plane), and a roof window 1.4 W/m²K or Window Energy Rating Band B. In an extension, glazing including rooflights is normally limited to 25% of the new floor area plus any windows or doors the extension covers, unless a whole-house calculation shows otherwise.
See our building regulations guide for U-values, glazing limits and self-certification.
Guide prices for Coulsdon
Guide prices for flat rooflights in Coulsdon are the same as anywhere we work — what changes the price is the job: access, structure, scaffold and finishing.
| 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 |
The process, step by step
- Tell us what you have. Send the CR5 postcode, a rough size and a couple of photos.
- 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.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Flat rooflights near Coulsdon
Other services in Coulsdon
Questions about flat rooflights in Coulsdon
How long does it take?
Fitting into a prepared upstand usually takes a day. Forming a new opening in an existing roof, including making good inside, is often two to three days.
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.
Can you fit into my existing flat roof?
Yes. We form a new opening, trim the joists, build and waterproof an upstand and make good the ceiling. A survey confirms the joist direction and roof build-up first.
Will I need planning permission in Coulsdon?
English householder permitted development (Class C) normally covers rooflights that stand no more than 0.15 m proud of the roof plane and stay below the highest part of the roof.
Do I need to be at home for the survey in Coulsdon?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
