Window styles
Triple glazed casement windows
If your current windows open outwards on friction hinges, they are casements. Replacing them with triple glazed casements keeps the familiar look and operation, while cutting heat loss through the glass by roughly half compared with ageing double glazing.
Summary
A casement window has sashes hinged at the side or top that open outwards, the most common window style in UK homes. A triple glazed casement holds a three-pane sealed unit in each sash and fixed pane, with stronger hinges to carry the extra weight.
What you get
| Opening | Side-hung or top-hung, outward opening |
|---|---|
| Hinges | Heavy-duty friction stays sized to the sash weight |
| Locking | Multi-point espagnolette lock, locking handle |
| Glass | Triple unit, argon filled, two low-e panes |
| Escape | Easy-clean or egress hinges where a fire escape window is needed |
| Typical lead time | 4 to 6 weeks in uPVC |
Guide prices
Guide prices per window, supply and fit, including removal of the old window.
Small window
about 600 x 1000 mm (bathroom, landing)
£695 – £845inc VAT · £580 – £705 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Medium window
about 1200 x 1200 mm (bedroom)
£895 – £1,095inc VAT · £745 – £910 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Large window
about 1800 x 1200 mm (lounge)
£1,395 – £1,695inc VAT · £1,160 – £1,410 ex VAT
- uPVC frame, triple glazed, warm-edge spacers
- Removal and disposal of the old window
- Fitted, sealed and made good inside and out
Guide prices, supply and fit. The written quote after your survey fixes the price for the specification shown; anything extra is agreed with you first.
Is it right for your home?
A good fit for
- Most 1930s to 1990s homes
- Like-for-like replacement of outward-opening windows
- Bedrooms needing an escape window
Think twice if
- Windows opening onto a walkway, where tilt and turn opens inwards
- Period homes that originally had sashes
Options
- uPVC, aluminium, timber or alu-clad
- Egress hinges for escape windows
- Restrictors for children’s rooms
- Georgian bars and leaded designs
- Obscure glass for bathrooms
Escape windows and hinges
In England, a replacement window must give at least the same means of escape as the old one. Where a bedroom or inner room needs an escape window, the clear opening must be at least 450 mm wide and high, at least 0.33 m², with the bottom of the opening no more than 1,100 mm above the floor. We check this on survey and fit egress hinges where they are needed.
Heavier sashes, stronger hinges
A triple glazed sash is heavier, so friction stays and handles are specified for the weight. That keeps the sash from dropping over time and keeps the seals compressed evenly.
Building Regulations by nation
| Nation | Replacement windows | Sign-off |
|---|---|---|
| England | 1.4 W/m²K, or a Window Energy Rating of band B or better | Competent person scheme or building control |
| Wales | 1.4 W/m²K, or a Window Energy Rating of band B or better | Competent person scheme or building control |
| Scotland | 1.6 W/m²K | No building warrant for a straight replacement; must meet the standards |
| Northern Ireland | 1.6 W/m²K, or a Window Energy Rating of band C or better | No building notice for a straight replacement; must comply |
Full regulations guide, with sources →
Questions about casement windows
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.
Are triple glazed casements harder to open?
They are a little heavier, but with correctly sized hinges they open and close smoothly.
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.
Related products
uPVC windows
From £695The lowest-cost way to get three panes of glass, in white or a woodgrain finish.
Learn more →
Flush casement windows
From £845Sashes that sit flush in the frame, like traditional timber windows.
Learn more →
Tilt and turn windows
From £795Inward-opening windows that tilt to vent and turn to clean.
Learn more →
Whole-house replacement
From £5,695Every window and door replaced in one planned visit.
Learn more →Casement windows by area
England
- Bedfordshire
- Berkshire
- Bristol
- Buckinghamshire
- Cambridgeshire
- Cheshire
- Cornwall
- County Durham
- Cumbria
- Derbyshire
- Devon
- Dorset
- East Riding of Yorkshire
- East Sussex
- Essex
- Gloucestershire
- Greater London
- Greater Manchester
- Hampshire
- Herefordshire
- Hertfordshire
- Isle of Wight
- Kent
- Lancashire
- Leicestershire
- Lincolnshire
- Merseyside
- Norfolk
- North Yorkshire
- Northamptonshire
- Northumberland
- Nottinghamshire
- Oxfordshire
- Rutland
- Shropshire
- Somerset
- South Yorkshire
- Staffordshire
- Suffolk
- Surrey
- Tyne and Wear
- Warwickshire
- West Midlands
- West Sussex
- West Yorkshire
- Wiltshire
- Worcestershire
Scotland
Casement windows: get your guide price
Use the guide-price tool, or book a free survey for a written quote that fixes the price.