Sieger Flush Casement Window

This flush casement window has been expertly engineered to enhance any project.


Designed with minimal sightlines and exceptional weather performance, this ultra-minimal flush window has a slimline sash of just 45mm. With a wide variety of glazing options, configurations and frame finishes available, the system can be designed completely bespoke for each project to ensure it meets specific design requirements.

Frame With: 45mm

Max Size: top hung 1400mm x 1200mm / side hung 700mm x 1400mm / ask the team about other configurations

Configurations: top hung / side hung / fixed / bottom hung / and more

Typical Glass Spec: 4mm – 18mm argon gas cavity – 4mm

Performance: air (4), water (9a), wind (E2400), acoustic (Rw 42 dB)

Security: PAS 24 & Secured by Design

gold framed three pane aluminium casement window with flush design

The system has full weather testing, a thermally broken aluminium frame and multi-point locking, offering unparalleled performance and security for your home.

The flush design and innovative framing details enables the window system to work in harmony with any building type. From listed buildings to contemporary new builds, this system offers uncompromised style and performance.

The slim 45mm sash runs the perimeter of the glass pane for an even and minimal design. Fully tested to PAS 24 and certified under the Secured by Design scheme, the Sieger Flush Casement meets all safety standards for complete peace of mind.

There are a range of configurations available for this flush window system including top hung, multi-light and fixed. Fixed versions of the windows can reach impressive weights of up to 250kg. Contact the team to discuss the full range of options.

See These at the Showroom

Come to the Sieger Showroom to see these aluminium windows in person. Just click the link at the bottom of the page to request an appointment or call the team who would be happy to help.

Request a Quotation

We would be happy to create a quotation for your project requirements. Click the link at the bottom of the page to request a quotation or speak to a member of the team to run through your specific project requirements. We can help tailor your glass package to ensure you achieve the design, performance and budget requirements for your project.

Visit our Showroom

The Sky House Design Centre

We are here to help. Contact us for Quotations, Technical Information, General Information and more.

What would you like to contact us about?