Skylight replacement for Llangefni: the essentials
Skylight replacement in Llangefni means replacing tired domes and failed glass with a modern rooflight. We cover the LL77 district and the rest of Gwynedd, with a survey before any price is fixed.
Slate roofs, stone cottages and terraced valleys are typical across Wales, and slim rooflights that sit low in the slates suit them best. Typical uses for skylight replacement include yellowed domes, misted glass and leaking roof windows.
From Llangefni to Bangor, Gwynedd, Caernarfon and Holyhead, the same survey-first process applies: measure, specify, fix the price, then fit.
What you can choose
- Roof window replacement in pitched roofs
- Like-for-like size replacement
- Fixed to electric opening
- Misted glass unit replacement only
- Upstand rebuild and insulation
- Cures most chronic leaks
- Clearer view and more light
Before you order: points to check
- A replacement is a chance to meet current thermal standards
- Upstand and roof condition decide the scope
Planning, building control and Llangefni
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. 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.
See our building regulations guide for U-values, glazing limits and self-certification.
Guide prices for Llangefni
The ranges below are typical for straightforward jobs; your fixed price follows a survey of your roof.
| 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 |
What happens next
- Tell us what you have. Send the LL77 postcode, a rough size and a couple of photos.
- 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.
- Fitting and handover. We install, clean down and leave product and warranty documents.
Neighbouring towns
More we do in Llangefni
Questions about skylight replacement in Llangefni
Will it mess up my ceiling?
We protect the room and make good the reveal. Minor decoration may be needed afterwards.
Do I need building regulations approval to replace a rooflight?
Replacements in existing homes generally need to meet current thermal standards and may need notification or approval. We advise on the route for your job.
Can I go bigger when replacing?
Possibly. Enlarging the opening means trimming joists, so we check the structure first.
Will I need planning permission in Llangefni?
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.
How do I book a survey in Llangefni?
Send your postcode and, if you can, a photo of the roof and the room. We offer a survey date when we reply.
