Sash windows · County Londonderry
Triple glazed sash windows in Derry
Triple glazed sash windows for homes in Derry: measured on a free survey, made to order and fitted by installation teams working for us across County Londonderry.
Vertical sliding sashes, made triple glazed where the design allows. A sash window has one or two sashes that slide up and down in a box frame.
Winter light and glass choice in Derry
On the shortest day, Derry gets about 7 h 10 min of daylight and the midday sun reaches only about 12° above the horizon. Low winter sun means north-facing rooms here gain little solar heat, which is where triple glazing’s lower heat loss helps most.
Guide prices in Derry
| Guide | Supply and fit, inc VAT |
|---|---|
| Small window about 600 x 1000 mm (bathroom, landing) | £1,295 – £1,595 |
| Medium window about 1200 x 1200 mm (bedroom) | £1,695 – £2,095 |
| Large window about 1800 x 1200 mm (lounge) | £2,595 – £3,195 |
Guide prices. Your written quote after the free survey fixes the price for the specification shown.
Rules for sash windows in Northern Ireland
The rules for replacement windows in Northern Ireland are set by Technical Booklet F1 (2022): 1.6 W/m²K, or a Window Energy Rating of band C or better. Replacing windows or external doors does not need full plans or a building notice, but the work must still comply; enlarging an opening or other structural change needs building control approval.
Before ordering: Check with your council planning office before changing the style, material or size of windows or doors, and always for listed buildings, conservation areas and flats.
How it works
We start with a survey, not a sales pitch: measurements, the structure above any bays, trickle-vent needs and escape windows. The quote that follows fixes the price, and anything unexpected on the day is agreed with you first.
- Guide prices published, not hidden
- No pressure: the quote is yours to keep
- Frames, glass and fitting in one contract
- Advice on planning and consents before you order
Questions from Derry
Can I keep my original sash boxes?
Sometimes. A timber specialist can fit new sashes into sound original boxes, but the glass thickness is limited by the sash depth.
How much do triple glazed sash windows cost?
Our guide starts at £1,295 for a small uPVC sash, fitted and inc VAT. Timber sashes cost more; UK quotes for timber triple sashes run past £3,000 each.
Do I need permission for triple glazed sash windows in Derry?
In Northern Ireland, check with your council planning office before changing the style, material or size of windows, and always for listed buildings and flats. Check whether your street is in a conservation area or covered by an Article 4 direction before changing the style.
Do you fit triple glazed sash windows in Derry?
Yes. We arrange surveys and fitting in Derry and across County Londonderry. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
Nearby
Nearby towns on our list include Strabane (22 km), Limavady (24 km), Coleraine (44 km) and Omagh (44 km).
Other products in Derry
- uPVC windows
- Aluminium windows
- Timber windows
- Alu-clad timber windows
- Casement windows
- Flush casement windows
- Tilt and turn 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
Sash windows in Derry: book your free survey
Written quote fixed for the specification, after a free survey. No building notice is needed for a straight replacement in Northern Ireland; we fit to the regulations and give you a written handover pack.