Casement windows · Wales
Triple glazed casement windows in Gwynedd
We survey and fit triple glazed casement windows across Gwynedd, from Bangor and Holyhead to smaller towns such as Porthmadog.

Like-for-like replacement for most post-war homes. A casement window has sashes hinged at the side or top that open outwards, the most common window style in UK homes.
Guide prices across Gwynedd
Small window
about 600 x 1000 mm (bathroom, landing)
£695 – £845inc VAT · £580 – £705 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Medium window
about 1200 x 1200 mm (bedroom)
£895 – £1,095inc VAT · £745 – £910 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Large window
about 1800 x 1200 mm (lounge)
£1,395 – £1,695inc VAT · £1,160 – £1,410 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Guide prices, supply and fit. The written quote after your survey fixes the price for the specification shown; anything extra is agreed with you first.
Towns in Gwynedd
Rules in Wales
Wales requires replacement windows to achieve 1.4 W/m²K, or a Window Energy Rating of band B or better, which good triple glazing passes comfortably. As in England, replacement windows are a controlled fitting: a competent person scheme installer self-certifies the work, or building control approves it.
Before ordering: Householder permitted development rules do not cover flats, and councils can remove rights with Article 4 directions. Listed buildings need listed building consent. Check with your council before changing the style or material.
How it works
The surveyor measures every opening, checks ventilation, escape windows and safety-glass zones, and talks through styles. Your written quote lists each item with its glass build-up and U-value, and the price is fixed for that specification.
- Every opening measured, including escape and vent needs
- Frames rated for the weight of triple glass
- Old windows removed and taken away
- Each opening closed up the same day
Questions
Are triple glazed casements harder to open?
They are a little heavier, but with correctly sized hinges they open and close smoothly.
Do casement windows need trickle vents?
If the old windows had them, yes, and at least as large. If not, ventilation must be no worse than before. We size this on survey.
What is an egress hinge?
A hinge that lets the sash open wide enough to climb out in a fire. It is used where a bedroom window is also the escape route.
Do you cover all of Gwynedd?
We arrange surveys and fitting across Gwynedd.
Do I need permission for triple glazed casement windows in Wales?
In Wales, householder rules do not cover flats, councils can use Article 4 directions, and listed buildings need consent.
Casement windows in nearby areas of Wales
Other products in Gwynedd
- uPVC windows
- Aluminium windows
- Timber windows
- Alu-clad timber windows
- Flush casement windows
- Tilt and turn windows
- Sash windows
- Bay and bow windows
- Fixed and picture windows
- Composite front doors
- French doors
- Sliding patio doors
- Bifold doors
- Glass-only replacement
- Acoustic triple glazing
- Security glazing
- Whole-house replacement
- New builds and self-builds
- Period homes and conservation areas
- Flats and apartments
- Passivhaus and EnerPHit
Casement windows across Gwynedd
Written quote fixed for the specification, after a free survey. Building Regulations sign-off by a competent person scheme installer or building control, as the law requires in Wales.
