Flat rooflights for Caernarfon: the essentials
We handle flat rooflights across Gwynedd, including Caernarfon. In short: fixed double or triple glazed rooflights for flat roofs and extensions. The survey checks structure, weathering and orientation, so the quote reflects your actual roof.
Welsh planning rules exclude rooflights from permitted development in conservation areas and National Parks, so we check the designation before quoting. Flat rooflights suit kitchen extensions, side returns and flat-roofed back rooms.
Caernarfon is around 13 km from Bangor, Gwynedd, and we survey and fit throughout that part of Gwynedd, including the LL55 district.
Specification options
- Rain sensor if paired with an opening unit
- Plastered or lined internal reveal
- Double or triple glazing
- Square, rectangular or long-format sizes
- Frame colours: anthracite, black, white or RAL
- Fixed units are simple, quiet and low-maintenance
- Pairs with an opening unit where you also need ventilation
Things we check at survey
- The roof membrane must be dressed up the upstand before the unit goes on
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
Planning, building control and Caernarfon
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. 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.
Welsh Building Regulations expect new or replacement rooflights to reach 2.2 W/m²K and roof windows 1.4 W/m²K or a Band B rating. A revised Welsh Approved Document L takes effect on 4 March 2027; rooflights in new dwellings stay at 2.2 W/m²K.
Read the planning permission guide before you commit to a design.
Flat rooflights prices in Caernarfon
These are typical supply-and-fit ranges. For an address in Caernarfon, 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 |
What happens next
- 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.
- Installation day. Usually one day into a prepared opening, longer for new openings.
Flat rooflights near Caernarfon
More we do in Caernarfon
Flat rooflights in Caernarfon: 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.
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.
Do you fit flat rooflights in Caernarfon?
Yes. We survey and fit flat rooflights in Caernarfon and across Gwynedd. Send your postcode and we will offer a survey date when we reply.
How do I book a survey in Caernarfon?
Send your postcode and, if you can, a photo of the roof and the room. We offer a survey date when we reply.
