Flat rooflights for Carmarthen: the essentials
We handle flat rooflights across Dyfed, including Carmarthen. 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.
Many Welsh homes have older single-storey rear extensions where a glass rooflight brightens a dark kitchen. Flat rooflights suit landings, bathrooms and rear extensions with flat roofs.
We work across Dyfed, including Carmarthen, and in neighbouring towns such as Llanelli and Ammanford. Access, parking and how the glass reaches the roof are all checked at the survey.
Specification options
- Double or triple glazing
- Integral or fitted blinds
- Rain sensor if paired with an opening unit
- Plastered or lined internal reveal
- Square, rectangular or long-format sizes
- Double or triple glazed with a warm-edge spacer
- Even, top-down daylight across the whole room
Things we check at survey
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
- New openings in an existing roof need a structural check on joists
Planning, building control and Carmarthen
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.
Guide prices for Carmarthen
Guide prices for flat rooflights in Carmarthen 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 |
What happens next
- Send the details. Postcode, rough size and a photo of the roof and room.
- Measure and check. A surveyor visits Carmarthen, measures and checks structure and access.
- Fixed quote. Product, work and price in writing — nothing is ordered until you agree.
- Fitting and handover. We install, clean down and leave product and warranty documents.
Neighbouring towns
More we do in Carmarthen
Common questions
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.
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.
Will I need planning permission in Carmarthen?
In Wales a rooflight on a house is usually permitted development if it stands no more than 15 cm proud of the roof, except on protected land such as conservation areas and National Parks, where permission is needed.
Do you fit flat rooflights in Carmarthen?
Yes. We survey and fit flat rooflights in Carmarthen and across Dyfed. Send your postcode and we will offer a survey date when we reply.
