What are flat rooflights?
Across South Glamorgan, our flat rooflights work covers fixed double or triple glazed rooflights for flat roofs and extensions. Survey first, fixed price second, fitting third.
Wales sees a lot of wind-driven rain, particularly in the west, so upstand height and flashing laps matter more than anywhere. Many Welsh homes have older single-storey rear extensions where a glass rooflight brightens a dark kitchen.
Towns in South Glamorgan
What you can choose
- Double or triple glazing
- Frame colours: anthracite, black, white or RAL
- Square, rectangular or long-format sizes
- Plastered or lined internal reveal
- Insulated kerb or timber upstand built to suit
- Even, top-down daylight across the whole room
- Pairs with an opening unit where you also need ventilation
Planning and building rules in Wales
Planning rules in Wales are tighter than in England for rooflights: Class C rights do not apply in conservation areas, National Parks or AONBs, so a rooflight there needs planning permission. Listed buildings need listed building consent from the council, and flats have no householder permitted development rights.
Approved Document L in Wales (2022 edition) sets 2.2 W/m²K for rooflights, measured horizontally, and 1.4 W/m²K or Band B for roof windows in existing homes. A revised Welsh Approved Document L takes effect on 4 March 2027; rooflights in new dwellings stay at 2.2 W/m²K.
Flat rooflights prices in South Glamorgan
These are typical supply-and-fit ranges. For an address in South Glamorgan, scaffold, a hoist for heavy glass, or a new structural opening can move the figure, which is why we survey first.
| 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
- Tell us about the roof. Send the postcode, rough sizes and a photo or two through the form, WhatsApp or the guide-price tool.
- Free survey. For new installations a surveyor measures the opening, checks the roof build-up and talks through glass and options.
- Fixed written quote. You get the product, the work and the price in writing. Nothing is ordered or paid for until you agree.
- Fitting and handover. We fit, seal and make good, then hand over product data, warranties and any certificate paperwork.
Flat rooflights in nearby areas
Common questions
Can a flat rooflight be walked on?
Not unless it is designed as a walk-on unit with structural laminated glass. A standard flat rooflight is for light only — if the roof is used as a terrace, choose a walk-on rooflight instead.
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.
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.
Do I need to be at home for the survey in South Glamorgan?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
