Flush casement windows · County Antrim
Triple glazed flush casement windows in Lisburn
Homes in Lisburn can have triple glazed flush casement windows supplied and fitted, with surveys arranged across County Antrim including BT27.

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 Lisburn
On the shortest day, Lisburn gets about 7 h 16 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 Lisburn
| 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
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
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.
- 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 Lisburn
Are flush casements more expensive?
Yes. Our guide puts them about 30% above a standard uPVC casement of the same size.
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.
How long does it take to get triple glazed flush casement windows fitted in Lisburn?
After the survey, typical manufacture time is 5 to 8 weeks, and most homes are fitted in 1 to 4 days.
Do I need permission for triple glazed flush casement windows in Lisburn?
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
We also cover nearby Belfast (11 km), Castlereagh (11 km), Newtownabbey (17 km) and Holywood (19 km).
Other products in Lisburn
- 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 Lisburn: 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.
