Slimline Aluminium styles

The Ultimate Sleek & Slimline

Flush Casement Windows

Designed to replicate the appearance of timber with sleek, slimline frames and authentic colours, our uPVC flush casement windows are ideal for any property. The sash fits flush into the frame for seamless sightlines.

#SternFensterAt50

spinning wheel image

The Ultimate Sleek & Slimline

Flush Casement Windows

Designed to replicate the appearance of timber with sleek, slimline frames and authentic colours. Our uPVC flush casement windows are ideal for any property. The sash fits flush into the frame for seamless sightlines.

#SternFensterAt50

spinning wheel image

Flush Casement Windows Key Features

Our flush sash windows look fantastic in any surrounding, with their flush external contours and elegant style. Georgian duplex bars can be incorporated into the design for further authenticity, transforming a modern townhouse into the archetypal country house many people dream of.

Offering superior weather resistance, our uPVC flush casement windows have a high performance multifunctional weatherseal. This continuous seal is welded at the corners, maintaining air tightness with no loss of comfort inside the home.

The Deceuninck flush sash window has a night vent locking position. This bespoke locking keep allows for secure ventilation as well as full hardware compatibility, giving the Heritage flush sash window unrivalled security.

Our flush casement windows are available in our standard grooved welded finish and our seamless StyleLine graf welded finish.

Flush Casement Windows Key Features

Our attractive flush casement windows are available in our standard welded grooved finish and our unique StyleLine seamless graf welded finish.

Our flush casement windows provide a U-value of 1.4 W/m2K and are A Energy Rated for superior thermal efficiency.

Optional PAS 24 accredited. These windows are built with night vent locking for secure ventilation. Give your customers peace of mind with flush casement windows from a multi-award winning manufacturer.

Choose from colour customisable inline, monkey tail and tear drop handles to offer your customers plenty of choices.

Our uPVC flush casement windows have a high performance multifunctional weatherseal. This continuous seal is welded at the corners, maintaining air tightness.

The StyleLine difference

StyleLine – the revolutionary welding process that eliminates the grooving stage. Use the slider below to see the StyleLine difference for yourself.

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non graf welded frame

The StyleLine difference

StyleLine – the revolutionary welding process that eliminates the grooving stage. Use the slider below to see the StyleLine difference for yourself.

LEARN MORE

non graf welded frame

High grade uPVC

To ensure performance and aesthetic are maintained over an extensive period, all materials used in the manufacture of our flush casement windows will require minimal input to ensure they operate to an ‘as new’ standard.

Due to the inherent qualities of high grade uPVC, these flush casement windows won’t rot, warp, rust, bow, crack or discolour over the years. This stands true even in the face of extensive use and prolonged exposure to the elements.

High grade uPVC

To ensure performance and aesthetic are maintained over an extensive period, all materials used to manufacture of our flush casement windows will require minimal input to ensure they operate to an ‘as new’ standard.

Due to the inherent qualities of high grade uPVC, these flush casement windows won’t rot, warp, rust, bow, crack or discolour over the years. This stands true even in the face of extensive use and prolonged exposure to the elements.

Transform Your Home's Look: Explore Our Window / Door Configurator - Preview Our Extensive Range of Interior and Exterior Shades With The “Turn Around” Icon.

Single Colours

Our single colours are readily stocked and available with quick turnarounds.

white white
White / White
deceuninck colour swatches casement windows
White Grain / White Grain
deceuninck colour swatches casement windows
Anthracite Grained / Anthracite Grained
deceuninck colour swatches casement windows
Classic Cream / Classic Cream
deceuninck colour swatches casement windows
Chartwell Green / Chartwell Green
deceuninck colour swatches casement windows
Rosewood / Rosewood
deceuninck colour swatches casement windows
Nut Tree / Nut Tree
deceuninck colour swatches casement windows
Irish Oak / Irish Oak
deceuninck colour swatches casement windows
Golden Oak / Golden Oak
deceuninck colour swatches casement windows
Black Ash / Black Ash
deceuninck colour swatches casement windows
Anthracite / Anthracite

Dual Colours

Enjoy interior and exterior customisation, as well as shorter delivery times with our stunning dual colour options.

Heritage Colours

Available for fast dispatch, our heritage colours offer shorter delivery times.

Premium Colours

Providing exceptional quality and individuality, our non stocked premium colour are available at an additional cost with extended lead times.

TURN AROUND

Unlimited Colours

The Deceuninck flush casement window is available in a wide range of foiled colours, helping you choose the perfect colour combination for your home. We also offer colour matching ancillaries, trims and accessories.

Transform Your Home's Look: Explore Our Window / Door Configurator - Preview Our Extensive Range of Interior and Exterior Shades With The “Turn Around” Icon.

Single Colours

Our single colours are readily stocked and available with quick turnarounds.

white white
White / White
deceuninck colour swatches casement windows
White Grain / White Grain
deceuninck colour swatches casement windows
Anthracite Grained / Anthracite Grained
deceuninck colour swatches casement windows
Classic Cream / Classic Cream
deceuninck colour swatches casement windows
Chartwell Green / Chartwell Green
deceuninck colour swatches casement windows
Rosewood / Rosewood
deceuninck colour swatches casement windows
Nut Tree / Nut Tree
deceuninck colour swatches casement windows
Irish Oak / Irish Oak
deceuninck colour swatches casement windows
Golden Oak / Golden Oak
deceuninck colour swatches casement windows
Black Ash / Black Ash
deceuninck colour swatches casement windows
Anthracite / Anthracite

Dual Colours

Enjoy interior and exterior customisation, as well as shorter delivery times with our stunning dual colour options.

Heritage Colours

Available for fast dispatch, our heritage colours offer shorter delivery times.

Premium Colours

Providing exceptional quality and individuality, our non stocked premium colour are available at an additional cost with extended lead times.

TURN AROUND

Unlimited Colours

These flush sash windows are available in a wide range of high quality colours, which will allow you to increase your customer base. You won’t have to turn business away as you accommodate all tastes and preferences. All of our colours are finished with a highly durable finish to reduce any required after sales.

Click through our showroom to explore our products in greater detail

Explore Our Virtual Showroom

Click through our showroom to explore our products in greater detail

Explore Our Virtual Showroom

The Ultimate Flush Casement Windows

Flush casement windows are a smart way of adding style to your home. No matter the home, whether it’s a new build, traditional, modern, period or even heritage property, these windows are perfectly suited to match all property types.

We offer a wide selection of configuration options, opening styles and panel counts, allowing you to find the perfect flush casement window for your home. Available in a range of colours and finishes, we’re flexible in ensuring that your demands are met with our comprehensive selection, spanning from high quality standard colours to traditional woodgrain foils.

open flush casement windows

State-Of-The-Art-Machinery

We are proud to have more than 50 years of manufacturing at Sternfenster and are fully committed to UK homeowners and offering sustainable products and services wherever possible. Working closely within the trade and retail industry, we offer nationwide delivery across our comprehensive portfolio.

Our state of the art machinery allows us to produce unique products that stand apart from the competition. Our attractive flush casement windows are no exception.

The Ultimate Flush Casement Windows

It doesn’t matter if your customers require new windows for a new build, traditional, modern, period, heritage or traditional home; these windows are perfectly suited.

Promote yourself as a reliable, efficient and professional installer with flush sash windows that are designed to last. We only offer our trade customers premium products because we know your customers won’t settle for anything less. Find out how to become a Sternfenster Approved Installer today.

State-Of-The-Art-Machinery

Inspired by traditional timber joinery, Deceuninck uPVC flush casement windows can be either fully grooved welded or StyleLine graff seamless finish for a more authentic appearance. This allows them to offer a traditional charm to new builds or an enhancing feature to traditional or conservation properties.

Partner with us for access to our state-of-the-art technology. At Sternfenster, we supply unique products at competitive trade prices.

Frequently Asked Questions

What is a flush sash window?

Are flush sash windows worth it?

How fast are your lead times?

Who is Sternfenster?

Frequently Asked Questions

How fast are your lead times?

Are your flush casement windows easy to install?

What advantages do Sternfenster offer?

How do I become a Sternfenster approved installer?

Who is Sternfenster?

Energy Savings Calculator

Use our energy savings calculator to find out how much upgrading your windows can save you in the long run.

Energy Savings Calculator

Use our energy savings calculator to find out how much your customers can save in the long run.

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