Casement windows · County Down
Triple glazed casement windows in Holywood
We arrange surveys and fitting of triple glazed casement windows in Holywood and the BT18 area, with a written, fixed quote after a free survey.

Side- and top-hung sashes with hinges sized for heavier glass. 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 Holywood
By midsummer Holywood has about 17 h 17 min of daylight, but in December only around 7 h 14 min, with the noon sun at about 12°. Triple glazing keeps more heat in during those long, dark months; big south and west windows may suit solar-control glass for summer.
Guide prices in Holywood
| 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.
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.
- Free survey and a written quote fixed for the specification
- Glass build-up and whole-window U-value on every quote
- Written handover pack at the end of the job
- Guarantees on frames, units and fitting in writing
Questions from Holywood
What is an egress hinge?
A hinge that lets the sash open wide enough to climb out in a fire. It is used where a bedroom window is also the escape route.
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 Holywood?
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 casement windows in Holywood?
Yes. We arrange surveys and fitting in Holywood and across County Down. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
Nearby
Also near Holywood: Newtownabbey (6 km), Belfast (8 km), Castlereagh (8 km) and Carrickfergus (9 km).
Other products in Holywood
- 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 Holywood: 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.
