Sliding patio doors · Wales
Triple glazed sliding patio doors in Gwynedd
Triple glazed sliding patio doors across Gwynedd: free survey, written fixed quote, and fitting by installation teams working for us. Towns we cover include Bangor, Holyhead and Porthmadog.

More glass, less cold: sliders that stay comfortable in winter. A sliding patio door has large glazed panels that slide past each other on a track, so it opens without swinging into the room.
Guide prices across Gwynedd
uPVC 2-pane slider
about 1.8 m wide
£1,895 – £2,295inc VAT · £1,580 – £1,910 ex VAT
- Triple glazed panels
- Removal of the old door or window
- Fitted, sealed and finished
uPVC 2-pane slider, wide
about 2.4 m wide
£2,295 – £2,895inc VAT · £1,910 – £2,410 ex VAT
- Triple glazed panels
- Removal of the old door or window
- Fitted, sealed and finished
Aluminium slider
about 3 m wide
£3,295 – £4,195inc VAT · £2,745 – £3,495 ex VAT
- Triple glazed panels
- Removal of the old door or window
- Fitted, sealed and finished
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 sets replacement door limits through Approved Document L for Wales (2022 edition, with 2024 amendments): 1.4 W/m²K, or a door set energy rating of band C (more than 60% glazed) or band B (other doors). Replacement external doors fall under the same energy rules as windows: 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 of a front door.
How it works
After the free survey you get a written quote naming the frame system, the glass build-up and the whole-window U-value for every item. Windows are made to order, then fitted, sealed and made good, one opening at a time.
- Free survey and a written quote fixed for the specification
- Glass build-up and door U-value on every quote
- Written handover pack at the end of the job
- Guarantees on frames, units and fitting in writing
Questions
Can I have a level threshold?
Low thresholds are available; they need a suitable drainage detail outside, which we check on survey.
How much does a triple glazed sliding door cost?
Our guide starts at £1,895 fitted for a 1.8 m uPVC slider and £3,295 for a 3 m aluminium slider, inc VAT. UK quotes for triple uPVC sliders run from about £1,600 to £2,600.
Do sliding doors need safety glass?
Yes, all door glass must be safety glass. Triple units in sliders are toughened or laminated.
Do you cover all of Gwynedd?
We arrange surveys and fitting across Gwynedd.
Do I need permission for triple glazed sliding patio doors in Wales?
In Wales, householder rules do not cover flats, councils can use Article 4 directions, and listed buildings need consent.
Sliding patio doors 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
- 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
Sliding patio doors 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.
