Ultra-slim frames

The thinnest aluminium wood window. Period.

Eterno aluminium timber composite windows ultra thin frame sliding balcony door

Enjoy the unobstructed view

Eliminate the boundaries between interior and exterior and maximise the natural light in your home with uninterrupted views. Our ultra-slim frame Alu-Clad windows are guaranteed to stand out with their stunning contemporary design.

The lightweight and durable frames can make up windows of over 4m in height while maintaining a profile as thin as 3.6 cm. Our ultra-slim windows by far outperform aluminium windows with a similar form factor and significantly better energy efficiency and aesthetics thanks to the warm timber frame.

Eterno aluminium timber composite windows ultra slim frame cross section

Timber frames as strong as steel

Each frame is structurally built up of three alternating softwood and hardwood layers, making the windows as strong as steel, while maintaining a low weight and supreme energy efficiency.

External Aluminium or structural glass cladding protects the windows from the elements and provides a sleek outside finish. High security 4 Season glazing with a warm edge spacer keeps the warm in during cold days and keeps the heat out during heatwaves.

Windows for life

Exceptional lifetime of 80+ years with a 10 year warranty and minimal maintenance

Sustainable & eco friendly

Мade in Italy from FSC and PEFC certified timber

More design freedom

Endless design possibilities with frame heights of 4 meters and above

Superb energy efficiency

Оutstanding U-values as low as 0.6 W/m2K thanks to cutting-edge technology


  • Superb energy efficiency – overall U-values from 0.6 W/m2K, covering the Passive House standard
  • Timber frames as strong as steel thanks to patented stratified wood and finger joint technology
  • Exceptional protection from the elements through Aluminium or structural glass external cladding
  • 4 Season (Low-Emissivity) glazing, laminated for safety
  • 15 year warranty and 80+ years expected lifetime

Internal veneer and external alu-clad finishes

  • Custom RAL colours available upon request

Handles and warm edge glazing spacers


  • Custom handle options available upon request
  • Аll-glass facade with structural glass external cladding
  • Flush interior with hidden hinges
  • Custom RAL colour internal and external finish
  • Astragal or Georgian bars for an elegant traditional look
  • Integrated rainwater drainage system for external sliding doors
  • Hassle-free motorised integrated blinds

Let’s talk about your project

Get in touch today and our experts will answer all of your questions. We’ll come up with a bespoke solution that best fits your project so we can help turn your vision into a reality!

Enquire today