What Are Flush And Non-Flush Casement Windows?

What Are Flush And Non-Flush Casement Windows?

If your home is overdue some new windows and you’d like some replacements, 5 Star is the place to come for them.

We have multiple window collections, including suites of flush casement windows and casement windows, two very different window products.

A ‘flush’ casement window gets its name because it’s exactly flush on the outside due to its window sashes sitting flush with the window frame.

Meanwhile, a standard casement window slightly differs as its window sashes slightly stretch past the window frame.

A side-on look at both windows will confirm this, and here’s some additional insight into the two solutions.

How long have flush and non-flush casements been around for?

The first flush casement window can be traced back to the 19th century, making it over 200 years old. Back then, timber was the only material used to build windows, so it had a wood-built construction.

Now you know why so many Georgian, Victorian and Edwardian homes have wooden flush windows.

The UK’s best-selling window, the non-flush casement window, pre-dates the flush casement by a century. In the 18th century, it was blacksmiths that built it and did so using iron, not timber.

A set of casement windows

Why are flush windows so popular again?

Because of companies like 5 Star!

We developed our Envisage collection of flush windows as we identified a growing want amongst customers for windows that are different to the norm to make their homes stand out.

Envisage has the proportions and lines of a traditional timber flush casement window, the window design it’s inspired by, but features a UPVC or aluminium profile to ensure modern thermal and security demands are met.

A close-up of a flush casement window frame

Which of them will complement my property?

Live in a conservation area or listed building? The planning department at your local authority is likely to accept flush UPVC windows as a window replacement as they mimic the styling of an original flush window design and will preserve its appearance.

Flush sash windows also have the pristine symmetry to match the aesthetic of contemporary dwellings. For these types of applications, they will often be finished in Black or Anthracite Grey.

The character of a standard casement window makes it compatible with just about any home, old or new, explaining its unrivalled appeal.

An oak effect flush casement window

Ask for a full product demonstration in your local 5 Star showroom if it will help you decide whether flush casements or standard casements are the right option for your home.


Our made-to-measure windows and doors have the potential to change your home not just on the outside, but the inside too. From the very latest energy saving windows in maintenance free UPVC to a host of replacement doors – all guaranteed to fit perfectly with your home.


Make your home warmer, quieter and more secure by fitting our very latest energy efficient replacement windows.



Our range of replacement doors offer all the advantages of low maintenance and high levels of security for total peace of mind.



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