A modern classic — sitting perfectly flush with the frame.
Flush casement windows are one of the most sought-after window styles in the UK right now, and for good reason. The sash sits completely flush within the outer frame when closed — giving the clean, square-edged appearance traditionally associated with timber cottage and farmhouse windows, but with all the performance and low-maintenance benefits of modern UPVC.
Whether you’re restoring a period property in Chester, finishing a new-build in Broughton, or simply replacing tired old windows on a family home in Deeside, flush casement windows are the style most homeowners are asking us for. They suit almost any property — traditional or contemporary.
What makes a flush casement window different?
On a standard casement window, the opening sash sits proud of the frame — it sticks out slightly when closed. On a flush casement, the sash sits perfectly level with the outer frame, creating a smooth, flat, almost timber-like finish from the outside.
That single design change gives you:
- A heritage, timber-effect appearance without the upkeep of real wood
- Clean, square sightlines that suit both period and modern homes
- A premium, considered finish that genuinely lifts a property’s kerb appeal
- Full compatibility with conservation areas and sensitive locations (check with your local planning office for guidance)
We supply flush casement windows in UPVC and they can be made to your exact sizes, colours and configurations.
Built to perform — not just to look good.
A flush casement window from Design Trade Windows is engineered for the same high standards as every other window we install:
- Energy efficient — A-rated as standard, with the option to specify higher ratings or low U-values down to 0.8 W/m²K
- Secure — multi-point locking, internally beaded glazing and high-security hardware fitted as standard
- Weather-tight — fully gasketed seals to keep out wind, rain and noise
- Low maintenance — no painting, no warping, no sticking; a wipe with warm soapy water is all they ever need
- Made to measure — every window is built to your exact opening, never off-the-shelf
Colour, finish and hardware — your choice.
This is where flush casement windows really come into their own. We offer a full range of woodgrain finishes — Anthracite Grey, Painswick, Cream, Chartwell Green, Agate Grey, Black, Irish Oak and many more — including authentic timber-effect foils that genuinely look like painted wood from the street.
Hardware can be specified to match the period of the property:
- Monkey-tail handles for a traditional, cottage feel
- Pear-drop handles for a refined, country-house look
- Modern straight handles for new-builds and contemporary homes
We’ll talk you through the options when we come out to measure up — there’s no pressure, and we’ll show you samples so you can see and feel the finish before you commit.
Where flush casement windows work best.
We fit flush casement windows across Deeside, Flintshire, Chester, Wrexham and the Wirral, and they suit a huge range of property styles:
- Period cottages and farmhouses where timber windows have come to the end of their life
- Victorian and Edwardian terraces where homeowners want a heritage look
- New-build properties where the developer’s standard windows are letting the house down
- Barn conversions and rural properties where a clean, traditional sightline is essential
- Conservation areas where the appearance of timber is desirable
If you’re not sure whether flush casement is the right style for your home, just give Karl a call — happy to pop out, take a look and give honest advice.
Get a Quote for Your Flush Casement Windows
Our Flush Casement Windows make the Grade
Window Energy Ratings are a simple way to compare how energy-efficient a window is, on an ‘A++’ to ‘E’ scale — the same kind of label you’ll see on fridges and washing machines.
Current building regulations require a ‘C’ rating. Our flush casement windows can be specified to achieve any rating on the scale, right up to A++, with U-values as low as 0.8 W/m²K. (Building Regulations require a U-value of 1.6 W/m²K, so we’re comfortably ahead of the standard.)
We’re also FENSA registered (number 44772), meaning every installation we carry out is signed off as compliant with current building regulations — and registered with your local authority on your behalf.
Why Choose Design Trade Windows?
Expert installation — from one local team. We don't sub-contract. When you book in with Design Trade Windows you'll deal directly with Karl from the first call through to the final fit. We're a local family business based in Connahs Quay, we're FENSA registered, and we've spent years building our reputation across North Wales and Cheshire on the simple basis of doing the job properly. Take a look at our reviews from genuine local customers — we're very proud of them.
Frequently Asked Questions about Flush Casement Windows
Find answers to commonly asked questions about our services.
Are flush casement windows more expensive than standard casement windows?
Typically yes — there’s a small premium over a standard casement window because of the extra engineering involved in making the sash sit perfectly flush. The exact cost depends on size, colour, glazing spec and quantity. We don’t charge for estimates, and Karl can normally come out within 24 hours.
Can flush casement windows be used in a conservation area?
Often yes. Because the flush finish so closely mimics traditional timber windows, they’re frequently approved in conservation areas where standard UPVC casements wouldn’t be. We always recommend checking with your local conservation officer before ordering, and we’re happy to help with the conversation if needed.
What's the difference between flush casement and flush sash?
Nothing — they’re two names for the same style of window. “Flush sash” is the term used more often in the trade and “flush casement” is the term most homeowners search for. Both refer to a casement window where the sash sits level with the outer frame.
Are flush casement windows available in aluminium as well as UPVC?
Yes. Aluminium flush casement windows give you even slimmer sightlines and a contemporary edge, while UPVC is the more cost-effective option and now comes in genuinely impressive timber-effect finishes. We’ll talk you through both when we visit.
How long does it take to install flush casement windows?
A typical full-house replacement takes between one and three days depending on the number of windows and access. We’ll give you a clear timeline upfront when we quote.
Do you offer a warranty on flush casement windows?
Yes — every window comes with a manufacturer’s warranty, and our workmanship is guaranteed too. We’ll go through the details with you in writing before any work starts.