70mm Flush Sash Windows by Flush Windows | High-Performance & Stylish Upgrade

DESIGNED FROM SCRATCH

The introduction of our original 70mm flush sash casement windows represents a pioneering achievement for Flush Windows Direct in the UK. Recognising the desire for a more authentic, heritage-inspired design, our team developed the 70mm flush sash system entirely from the ground up—delivering a window solution that seamlessly marries timeless elegance with modern performance.

STYLISH

These sleek, flush-fitting windows from Flush Windows Direct remove any visible uPVC overlap, combining the energy efficiency of modern materials with the warmth and character of traditional timber aesthetics.

THERMALLY EFFICIENT

For many homeowners, achieving the traditional look of timber frames is essential—often to meet planning regulations or maintain a heritage aesthetic. Flush sash windows from Flush Windows Direct incorporate a patented bubble gasket for exceptional weatherproofing, and can even be mechanically jointed to deliver a truly authentic, timber-inspired finish.

These windows don’t just look great; they also provide A+ energy ratings and U-values as low as 1.2 W/m²K, ensuring year-round comfort and helping to lower your energy costs.

TECHNICAL INFORMATION

MATERIAL

PVCu

STYLING

Sculptured

FRAME DEPTH

70mm

Profile

Standard with EnergyPlus outer frame

GLAZING

28mm IGU

LOWEST U-VALUE

1.2 W/m²K (Whole window)

BEST ACOUSTIC RATING

35 (-1;-4)

Highest Energy Rating

A+

Patented Bubble Gasket

Yes

Contains Recycled Material

Fully Recyclable

Yes

Alternative styles

Georgian / Astragal Bars

Give the illusion that a window is divided into much smaller panes; fitted on either inside or outside or both.

Arched Top

Flush windows direct profiles can be curved by specialists to form arched or even circular shapes.

Bow and Bay Windows

Allows windows to be coupled together to form a bow or bay window configuration.

French Windows

Made from a dual sash opening allowing for better views and increased ventilation.

CORNER WELD OPTIONS

Mechanical Joint

Mechanical joints are typically classed as the traditional style of corner weld options.

Welded joint

A welded joint can be differentiated by its diagonal style joint.

Timberweld®

A Timberweld joint gives the appearance of a mechanical joint on the outside, with a traditional weld on the inside.

Your Windows, Your Way

At Flush Windows Direct, we recognize that every homeowner’s needs are unique. That’s why our 70mm flush sash windows offer extensive customization options. Whether you prefer classic white, authentic woodgrain effects, or modern colour tones, you’ll find a finish that resonates with your personal style. This level of flexibility lets you create windows that perfectly complement your home’s character, delivering a bespoke solution that truly reflects who you are.

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70mm Flush Sash Window FAQs

What are flush sash casement windows?

Flush sash casement windows blend the classic character of pre-1932 timber frames with today’s advanced thermal performance. Flush Windows Direct recreates the authentic timber look using mechanical joints—perfect for homeowners who need traditional-style windows due to planning guidelines or environmental considerations, while still enjoying modern comfort and efficiency.

Do Flush Windows Direct 70mm Flush Sash Windows Require Much Maintenance?

These windows are notably low-maintenance—just give the frames an occasional wipe with mild detergent to keep them looking like new. As with any window or door system, we recommend oiling the moving parts annually to ensure smooth, trouble-free operation.

Why Are Flush Windows Direct’s Flush Sash Windows a Good Choice for Period Properties?

Our flush sash windows capture the authentic charm of traditional frames, making them perfectly suited for historically significant homes. They deliver the classic aesthetics required for conservation guidelines, while simultaneously enhancing energy efficiency, security, and low-maintenance convenience. The result is a window solution that maintains your property’s timeless appeal without sacrificing modern comfort and performance.

Can Flush Windows Direct’s Flush Sash Windows Be Used in Conservation Areas?

Yes. Many homeowners face strict planning or environmental requirements that call for a traditional timber frame appearance. Timber windows, however, can be costly, high-maintenance, and challenging to replace. Flush Windows Direct’s flush sash windows address these concerns by offering a selection of realistic foiled finishes and the option for mechanical joints—delivering an authentic timber look that meets conservation guidelines, without the expense or upkeep of actual wood.

What Type of Finish Can Flush Windows Direct’s Flush Sash Windows Have?

We provide a range of foiled finishes for our flush sash casements. Whether you’re drawn to the timeless warmth of authentic woodgrain or the sleek sophistication of a modern grey, you’ll find a variety of colours that perfectly match your home’s style and character.

70mm Flush Sash Window