Skylight replacement in Carmarthen: what is involved?
Thinking about skylight replacement in Carmarthen? The short answer: replacing tired domes and failed glass with a modern rooflight. The longer answer depends on your roof, which is why we survey before we price.
Many Welsh homes have older single-storey rear extensions where a glass rooflight brightens a dark kitchen. Skylight replacement suits yellowed domes, misted glass and leaking roof windows.
Carmarthen is around 22 km from Llanelli, and we survey and fit throughout that part of Dyfed, including the SA31 district.
Choices for your Carmarthen project
- Upstand rebuild and insulation
- Misted glass unit replacement only
- Roof window replacement in pitched roofs
- Dome to flat glass upgrade
- Like-for-like size replacement
- Usually done in a day
- Often reuses the existing opening
Things we check at survey
- Enlarging the opening changes the structure and may need approval
- A replacement is a chance to meet current thermal standards
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.
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.
Read the planning permission guide before you commit to a design.
Skylight replacement prices in Carmarthen
Prices below are shown including and excluding VAT. In Carmarthen, as elsewhere, making good inside and access equipment are the main variables.
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Replacement with upstand rebuild and opening unit | £2,995 – £4,795 | £2,495 – £3,995 |
| Dome to flat glass upgrade Typical | £1,915 – £2,995 | £1,595 – £2,495 |
| Like-for-like glass rooflight | £1,555 – £2,155 | £1,295 – £1,795 |
The process, step by step
- Tell us what you have. Send the SA31 postcode, a rough size and a couple of photos.
- Measure and check. A surveyor visits Carmarthen, measures and checks structure and access.
- Agree the quote. You approve the specification and price before anything is ordered.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Nearby towns
Other services in Carmarthen
Common questions
Can I go bigger when replacing?
Possibly. Enlarging the opening means trimming joists, so we check the structure first.
Can you replace only the misted glass?
Sometimes, if the frame is sound and the maker supplies replacement units. Often a complete new rooflight costs little more and performs better.
How long does a replacement take?
Usually a day for a standard rooflight on a sound upstand.
Do I need to be at home for the survey in Carmarthen?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
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.
