Our double glazed windows

We offer a range of high-performance double glazed windows for both our AURA & AURAPLUS and FORMA & FORMAPLUS ranges. Whether you’re after the modern look or seeking something more traditional, we’ve got the right style to suit you.

What’s more, each one is completely made to measure, so you know you’ve got a truly bespoke final product.

Our double glazing in numbers:

AURA 1.29 W/m2 K U-value, 41 dB* Rw sound reduction
AURAPLUS 1.29 W/m2 K U-value, 40 dB* Rw sound reduction
FORMA 1.27 W/m2 K U-value, 40 dB* Rw sound reduction
FORMAPLUS 1.28 W/m2 K U-value, 40 dB* Rw sound reduction

If you’re not sure which one’s right for your project or home, don’t worry – we’re the experts! Just get in touch and we’ll be happy to advise you.

Browse all double glazed windows

Our double glazed doors

Looking to invite plenty of light into your indoor space, while still keeping in that essential warmth? Then double glazed doors are a great option. We offer a range of different styles, each one ready to be manufactured to suit your requirements.

Browse all double glazed doors

* The acoustic performance of 42 dB and 43 dB is for our highest performing acoustic glazing

Classic energy efficiency for every style of home

Not only are double glazed windows and doors incredibly durable, they’re also energy efficient. Here at Rationel we believe everyone deserves beautiful windows and doors, ones that not only provide sanctuary and security but are also kind to the planet. With our double glazing, you’ve got the full package.

Learn more about our energy efficient products.

Useful guides for aluminium clad timber windows

Check out our helpful guides for information on everything from distributors to installation advice.

Downloadable links


Good aftercare is essential if you want your windows to last for decades to come – our aftercare information has got you covered.

Downloadable links