Alumina by Liniar


The Liniar design team is constantly pushing the boundaries of product innovation, finding clever solutions to challenges that others have failed to address.

Continued investment in infrastructure, technology, machinery and a great team of people has helped Liniar to become one of the market leading PVCu window systems with a customer base of specialist fabricators all over the UK.

Liniar’s latest innovation, Alumina by Liniar, is a true aluminium bi-folding door system, beautifully sculptured and foiled to match perfectly with the full Liniar product suite.

Designed by experts

Alumina is more energy efficient than other aluminium bi-fold doors – with U-values as low as 1.2 W/m²K.

Liniar were the first to launch a bespoke PVCu bi-folding door system with associated patented hardware and have more than 500 years of industry experience between them – the same team of experts have designed and developed Alumina by Liniar.

The latest development from this ground-breaking company and team, Alumina heralds the arrival of a new breed of bi-folding doors.

See our video showing the correct way to open and close an Alumina bi-fold door here.

Mark II Loves Alumina Bi-Fold Doors!

“A ‘true’ aluminium door with all the benefits of PVCu! Foiled finishes, U-values as low as 1.2, sash sizes 2.5m high and 1.2m wide and a patented polymer lock – what more could you want!”

Hi, I'm Mark II
Head of Testing at Liniar

Explore our Alumina Bi-fold Doors

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Choose your colour

Powder Coat


  • Sculptured
  • Chamfered


Why Choose Alumina?

Strength with size

Commercial and heavy-duty applications require greater strength, with wider and taller panes of glass and bigger spans. Alumina by Liniar is a true aluminium door, manufactured with standard aluminium machinery, with panes spanning up to 1.2 metres wide and 2.5 metres high.

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Perfectly matching

As well as being available in practically any powder-coated colour imaginable, what makes Alumina unique is that it’s also available in a beautiful woodgrain or flat foiled finish, enabling consumers to choose a style that perfectly matches the windows of their property for a perfect finish.

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Superior U-values

The Liniar range is renowned for its energy efficiency – Alumina is no different. Pushing the boundaries of thermal performance, it offers ‘true’ U-values as low as 1.2W/m²k thanks to its innovative thermal lock and large thermal breaks.

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With Alumina you can be sure of the highest security. Its suite of hardware includes multiple bi-directional locking points, shootbolts, built-in anti-lift features and anti-bump cylinders, ensuring it achieved PAS 24 enhanced security accreditation at the first attempt, and holds Secured by Design status.

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Alumina Bi-fold doors are available in a range of opening configurations from 1 to 7 panes so they can be truly tailored to your requirements.


The Alumina Bi-fold is packed full of innovative features, including folding keys, ergonomic handles and discreet magnets, the attention to detail is what makes the Alumina Bi-Fold 'best in class.'

Customer choice

Alumina Bi-fold doors are available with a range of powder coated and foiled colours along with additional options, from handles and hinges, to low and half thresholds.

Fully Tested Products


Our Alumina bi-fold door has been security and weather tested and satisfies the demanding requirements of PAS 24 and Secured by Design.