Window style comparison · 2026
Casement vs Sash Windows Cost
Casement and sash windows are not simply two styles at the same price. A standard uPVC casement is the baseline product in most replacement projects; sash windows use a different frame and operating system and typically carry a much higher fitted cost.
Quick price answer: For a medium window, our model gives £371–£675 for standard uPVC casement, £665–£1,156 for uPVC sash and £1,120–£2,036 for engineered timber sash.
Medium window price comparison
The three examples use the same UK-average model and medium-size assumption.
Figures are modelled UK-average fitted-market estimates from the Window Price Calculator engine, using its 24 September 2026 research refresh. They include ordinary removal, standard fitting, basic making good and VAT; scaffolding, hidden structural repairs and highly bespoke work can sit outside the range.
Price and practical differences
The most important difference is the construction of the window rather than the glass alone.
| Window | Typical fitted range | Best suited to |
|---|---|---|
| uPVC casement | £371–£675 | Lowest-cost mainstream replacement |
| uPVC sash | £665–£1,156 | Traditional appearance without timber pricing |
| Engineered timber sash | £1,120–£2,036 | Period character and real timber specification |
What happens across a whole project?
The difference becomes much larger when the same style is repeated across several openings.
Six standard casements
A six-window standard uPVC example is £2,006–£3,644. Job-size efficiencies are already reflected in the model.
Six sash windows
Six uPVC sash windows model at £3,988–£6,937; six engineered timber sash windows rise to £6,723–£12,214.
Use your own project
Start a replacement estimate.
Use the calculator to price a complete replacement window or door. Choose the closest product and project size and we’ll carry those choices into the full calculator.
Rough sizes are fine. The full personalised result is unlocked after the £2.99 checkout.Related price guides
Use the closest related guide to compare another specification or project type.
Questions people ask
Are sash windows more expensive than casement windows?
Usually, yes. Their frames, balances and traditional proportions make sash systems more expensive than standard uPVC casements in comparable sizes.
How much more is a uPVC sash window?
In our medium examples the centre rises from about £523 for standard casement to about £910 for uPVC sash.
Are timber sash windows much more expensive?
Our medium engineered-timber sash example is £1,120–£2,036, reflecting the material and construction premium.
Compare the style you are actually considering.
Start with casement or sash, then change the material and quantity inside the calculator to see the project-level difference.
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