What do flat rooflights involve?
Flat rooflights in Gwynedd means fixed double or triple glazed rooflights for flat roofs and extensions. Every quote follows a survey of the roof and the room below.
Slate roofs, stone cottages and terraced valleys are typical across Wales, and slim rooflights that sit low in the slates suit them best. Many Welsh homes have older single-storey rear extensions where a glass rooflight brightens a dark kitchen.
Towns in Gwynedd
What you can choose
- Plastered or lined internal reveal
- Frame colours: anthracite, black, white or RAL
- Solar-control or self-cleaning outer pane
- Rain sensor if paired with an opening unit
- Integral or fitted blinds
- Double or triple glazed with a warm-edge spacer
- Even, top-down daylight across the whole room
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. A side-facing rooflight within 10.5 m of the boundary must be obscure-glazed, and non-opening unless the opening part is more than 1.7 m above the floor.
In Wales the limiting values are 2.2 W/m²K for a rooflight and 1.4 W/m²K (or WER Band B) for a roof window in an existing house. Wales also has its own overheating rules (Part O) for new homes, in force since November 2022.
Flat rooflights prices in Gwynedd
These are typical supply-and-fit ranges. For an address in Gwynedd, 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 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.
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.
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.
Will I need planning permission in Gwynedd?
Welsh householder permitted development (Class C) allows rooflights that project no more than 15 cm and sit no higher than the existing roof — but not in conservation areas, National Parks, AONBs or World Heritage Sites.
