Casement windows · County Londonderry
Triple glazed casement windows in Derry
We arrange surveys and fitting of triple glazed casement windows in Derry and the BT47 area, with a written, fixed quote after a free survey.

The familiar outward-opening window, made triple glazed. A casement window has sashes hinged at the side or top that open outwards, the most common window style in UK homes.
Winter light and glass choice in Derry
In Derry, midday sun in late December sits around 12° high, with roughly 7 h 10 min of daylight. For windows facing north or shaded by neighbours, cutting heat loss matters more than solar gain; on open south-facing glass, ask about a higher solar-gain unit.
Guide prices in Derry
| Guide | Supply and fit, inc VAT |
|---|---|
| Small window about 600 x 1000 mm (bathroom, landing) | £695 – £845 |
| Medium window about 1200 x 1200 mm (bedroom) | £895 – £1,095 |
| Large window about 1800 x 1200 mm (lounge) | £1,395 – £1,695 |
Guide prices. Your written quote after the free survey fixes the price for the specification shown.
Rules for casement windows in Northern Ireland
In Northern Ireland, replacement windows must meet 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.
- 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 from Derry
Can my existing casement layout stay the same?
Yes. We match the existing layout unless you ask for a change, which can matter for planning in conservation areas.
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.
Do I need permission for triple glazed casement 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.
How long does it take to get triple glazed casement windows fitted in Derry?
After the survey, typical manufacture time is 4 to 6 weeks in uPVC, and most homes are fitted in 1 to 4 days.
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
- 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 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.
