Casement vs Flush Casement Windows

A small profile difference that changes the whole character of a façade.

Standard and flush casements work the same way. The difference is what happens at the edge of the sash — and on a period property that detail is the difference between a window that looks right and one that does not.

Here is what to look at.

The profile difference

On a standard casement the opening sash sits proud of the frame. On a flush casement the sash closes into the frame so the outer faces sit level, mimicking traditional timber joinery.

Where flush casements are worth it

Cottages, stone properties, period terraces and conservation areas — anywhere the eye expects a traditional flat façade. On a modern semi, a standard casement is perfectly appropriate and costs less.

Performance and cost

Both seal well when correctly fitted; flush systems generally cost more due to the frame design. Neither is harder to clean or maintain than the other.

See the profiles side by side

We'll bring samples to your survey so you can compare the sightlines on your own elevation.

Frequently asked questions

Are flush casements more energy efficient?

Not inherently. Energy performance comes from the glazing unit, spacer bar and frame system rather than whether the sash is flush.

Can I have flush casements at the front only?

Yes, and it's a common way to spend the budget where it shows.

Do flush casements suit modern homes?

They can look excellent on modern homes too, particularly in dark colours with slim sightlines.

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