Sash windows · County Down
Triple glazed sash windows in Castlereagh
From the first measure to the handover pack, we handle triple glazed sash windows for homes in Castlereagh and the rest of County Down.
Honest advice on which sashes can take a full triple unit. A sash window has one or two sashes that slide up and down in a box frame.
Winter light and glass choice in Castlereagh
Winter days in Castlereagh are short: about 7 h 15 min of daylight on 21 December, with the sun peaking near 12°. That low angle reaches deep into south-facing rooms, so we match the glass to each elevation rather than using one spec for the whole house.
Guide prices in Castlereagh
| 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
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.
Planning: 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
The surveyor measures every opening, checks ventilation, escape windows and safety-glass zones, and talks through styles. Your written quote lists each item with its glass build-up and U-value, and the price is fixed for that specification.
- 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 Castlereagh
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.
Are uPVC sashes allowed in conservation areas?
It depends on the council and any Article 4 direction. Timber is often expected on front elevations. Check before ordering.
Do you fit triple glazed sash windows in Castlereagh?
Yes. We arrange surveys and fitting in Castlereagh and across County Down. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
Do I need permission for triple glazed sash windows in Castlereagh?
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.
Nearby
Also near Castlereagh: Belfast (4 km), Holywood (8 km), Newtownabbey (10 km) and Lisburn (11 km).
Other products in Castlereagh
- 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 Castlereagh: 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.