Flat rooflights for Cambridge: the essentials
Thinking about flat rooflights in Cambridge? The short answer: fixed double or triple glazed rooflights for flat roofs and extensions. The longer answer depends on your roof, which is why we survey before we price.
Flat, open landscape in much of the East means roofs take the wind, so upstand and seal details matter more than the brand of glass. In Cambridge, as anywhere, flat rooflights are the usual choice for landings, bathrooms and rear extensions with flat roofs.
Cambridge is around 48 km from Peterborough, and we survey and fit throughout that part of Cambridgeshire, including the CB1 district.
Choices for your Cambridge project
- Insulated kerb or timber upstand built to suit
- Plastered or lined internal reveal
- Rain sensor if paired with an opening unit
- Frame colours: anthracite, black, white or RAL
- Integral or fitted blinds
- Inner pane laminated for safety overhead
- Fixed units are simple, quiet and low-maintenance
Things we check at survey
- Needs a properly formed upstand — usually at least 150 mm above the finished roof surface (check the manufacturer's figure)
- The roof membrane must be dressed up the upstand before the unit goes on
Planning, building control and Cambridge
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. A rooflight on a side-facing slope must be obscure-glazed, and fixed shut unless the opening part is more than 1.7 m above the floor.
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. 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 Cambridge
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 |
How the job runs
- Send the details. Postcode, rough size and a photo of the roof and room.
- Survey. We measure the opening, check the roof build-up and agree the options.
- Fixed quote. Product, work and price in writing — nothing is ordered until you agree.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Nearby towns
Other services in Cambridge
Flat rooflights in Cambridge: questions
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.
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.
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.
Is the survey in Cambridge free?
Yes for new installations. Repair visits are charged, and we tell you the price before we book.
How do I book a survey in Cambridge?
Send your postcode and, if you can, a photo of the roof and the room. We offer a survey date when we reply.
