Whole-house replacement · Wales
Whole-house triple glazing in Gwynedd
We survey and fit whole-house triple glazing across Gwynedd, from Bangor and Holyhead to smaller towns such as Porthmadog.

Whole-house guide prices for 2-, 3- and 4-bed homes. Whole-house triple glazing means replacing every window, and usually the external doors, in one job.
Guide prices across Gwynedd
2-bed terrace
5 windows + front door
£5,695 – £7,195inc VAT · £4,745 – £5,995 ex VAT
- White uPVC, triple glazed
- All old frames removed and taken away
- One fitting team, usually 1 to 2 days
3-bed semi
9 windows + front door
£9,395 – £11,795inc VAT · £7,830 – £9,830 ex VAT
- White uPVC, triple glazed
- All old frames removed and taken away
- Usually 2 to 3 days on site
4-bed detached
12 windows + front door + French doors
£13,595 – £16,995inc VAT · £11,330 – £14,160 ex VAT
- White uPVC, triple glazed
- All old frames removed and taken away
- Usually 3 to 4 days on site
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
In Wales, replacement windows must meet 1.4 W/m²K, or a Window Energy Rating of band B or better. 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
You will know exactly what you are buying: the quote states the unit build-up, frame, finish, fitting work and how Building Regulations compliance is handled. On fitting day each opening is replaced and closed up before the team moves on.
- Free survey and a written quote fixed for the specification
- Glass build-up and whole-window U-value on every quote
- Written handover pack at the end of the job
- Guarantees on frames, units and fitting in writing
Questions
How much does it cost to triple glaze a 3-bed semi?
Our guide is £9,395 to £11,795 for 9 uPVC windows and a front door, fitted and inc VAT. UK quotes typically range from about £6,500 to £11,000 for windows only.
Do I need to move out?
No. We work room by room and make each opening weathertight the same day.
Will I need scaffolding?
Most two-storey homes can be done from ladders or towers. Where scaffolding is needed, it is quoted separately.
Do you cover all of Gwynedd?
We arrange surveys and fitting across Gwynedd.
Do I need permission for whole-house triple glazing in Wales?
In Wales, householder rules do not cover flats, councils can use Article 4 directions, and listed buildings need consent.
Whole-house replacement in nearby areas of Wales
Other products in Gwynedd
- uPVC windows
- Aluminium windows
- Timber windows
- Alu-clad timber windows
- Casement 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
- New builds and self-builds
- Period homes and conservation areas
- Flats and apartments
- Passivhaus and EnerPHit
Whole-house replacement 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.
