The trusted aluminium and PVCu supply for trade and commercial projects

Combining elegance with outstanding performance

Capturing the aesthetic appeal of traditional timber casement windows with contemporary-style windows tailored for modern homes or offices, Alitherm 600 provides the perfect blend of tradition and innovation for a flawless aluminium window.

A traditional look

Alitherm 600 features a sculptured ‘ovolo’ profile designed to echo the traditional look of timber.

Energy efficient

Alitherm 600 achieves a window energy rating of ‘B’ and a U-value of 1.3W/m²K (using the correct glass unit).


Alitherm 600 is designed to comply with the revisions to the Building Regulations and is Document L compliant for the highest standard.

The perfect colour finish

Available in a wide selection of window styles and different colour options, including metallic, dual colour, and Smart's Sensations textured finishes.


Ultra-slim contemporary high quality aluminium windows

The Smarts Alitherm 600 window range is a versatile aluminium casement window system which is perfect for UK installers. Featuring slim sightlines, it includes a variety of high-quality glazing solutions for side and top-hung open-out windows making them the perfect choice and suitable for both replacement windows as well as new aluminium windows and new build houses, extensions or commercial developments.

For energy efficiency, it also incorporates Smart’s innovative polyamide thermal break technology, effectively forming a barrier between the cold external air and the warm internal air to prevent heat loss and enhance thermal efficiency, while it's also weather resistant and durable for longevity. For security, multipoint shoot-bolt locking mechanisms are fitted as standard and the aluminium frames are low maintenance.

Get In Touch

We have been using TWR since we started our company in 2014. They have always given a friendly and efficient service so I would have no hesitation in recommending them to other installers.

Cumbria Windoworks

Having worked with TWR for over eight years and purchasing all our commercial and aluminium products from them I can’t recommend them highly enough. They provide us with high-quality windows and doors efficiently and at a very competitive price

Everglade, Manchester

We have worked with TWR for 10 years, the product supplied is nothing short of excellent, and the enquiry stage is smooth all the way through to the aftercare. Commercial or domestic TWR will advise on and support you through ordering!

TWG, Lincoln

Dealt with Terry and Dawn, simple and to the point ordering of windows and aluminium Bifolds. Very helpful and honest.

Can recommend to anyone!

Dan C