Flush casement windows · County Londonderry
Triple glazed flush casement windows in Derry
From the first measure to the handover pack, we handle triple glazed flush casement windows for homes in Derry and the rest of County Londonderry.

Traditional flush sashes, a three-pane unit and heritage colours. A flush casement window has sashes that close flush with the outer frame instead of overlapping it, copying the look of traditional timber windows.
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) | £845 – £1,095 |
| Medium window about 1200 x 1200 mm (bedroom) | £1,195 – £1,495 |
| Large window about 1800 x 1200 mm (lounge) | £1,795 – £2,195 |
Guide prices. Your written quote after the free survey fixes the price for the specification shown.
Rules for flush casement windows in Northern Ireland
Northern Ireland requires replacement windows to achieve 1.6 W/m²K, or a Window Energy Rating of band C or better, which good triple glazing passes comfortably. 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
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.
- 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
Will they be accepted in a conservation area?
Flush designs are often the closest match to original timber windows, but each council decides. See our conservation guide and check any Article 4 direction.
Are flush casements more expensive?
Yes. Our guide puts them about 30% above a standard uPVC casement of the same size.
How long does it take to get triple glazed flush casement windows fitted in Derry?
After the survey, typical manufacture time is 5 to 8 weeks, and most homes are fitted in 1 to 4 days.
Do you fit triple glazed flush casement 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
- 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
Flush casement 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.
