![Night view of a high-rise building with an open parallel window in the glass façade.](/sites/default/files/public/styles/page_header_large/public/2022-03/Reynaers-Aluminium-U-value-3.png?h=16a6ccf5&itok=8R6oQIZ-) 07 March 2022 # U-value: what does thermal insulation mean for your building project? Sustainable homes and buildings are the only way forward. Every aspect counts. A less known, yet extremely significant factor to measure energy efficiency is the U-value. The lower it is, the better the thermal efficiency or insulation. Rising energy costs and growing sustainability awareness have considerably increased the focus on a building’s energy performance. Efficiency standards – imposed and often made stricter by regulation – are a major indirect driving force behind enhancing the comfort level of a project. Thanks to an optimal U-value, you not only save energy, you also increase your quality of life. ![Detail view of the Reynaers Experience Centre’s glass façade.](/sites/default/files/public/styles/landscape_small/public/2022-03/Reynaers-Aluminium-U-value-1.jpg?h=7721ddbf&itok=Jzvmvbti) ![Woman indoors, standing in front of large sliding window.](/sites/default/files/public/styles/image_max_width/public/2022-03/Reynaers-Aluminium-U-value-2.jpg?itok=rKUMZdPa) Share this story - [f](https://www.facebook.com/sharer/sharer.php?u=https%3A//www.reynaers.co.za/markdownify/node/6279%3Futm_source%3Dfacebook%26utm_medium%3Dsocial%26utm_campaign%3Dwebsite) - [t](https://twitter.com/intent/tweet?text=https%3A//www.reynaers.co.za/markdownify/node/6279%3Futm_source%3Dtwitter%26utm_medium%3Dsocial%26utm_campaign%3Dwebsite) - [l](https://www.linkedin.com/shareArticle?mini=1&url=https%3A//www.reynaers.co.za/markdownify/node/6279%3Futm_source%3Dlinkedin%26utm_medium%3Dsocial%26utm_campaign%3Dwebsite) - [p](https://pinterest.com/pin/create/button/) - [m]() ## You might also like [ See all stories ](/stories) - ![Close up of glazed façade](/sites/default/files/public/styles/teaser_medium/public/2026-03/150478F0005-BOSL.jpg?h=17fd743d&itok=sJUFKDUv) ### Low-carbon simulation and optimisation at Reynaers Aluminium [](/inspiration/stories/sustainability/low-carbon-simulation-and-optimisation) Read this - ![ReTurn logo in front of pile of aluminium scrap in blue bin.](/sites/default/files/public/styles/teaser_medium/public/2026-03/reynaers-aluminium-return-banner.png?h=61f1cca7&itok=l0XPyQ3N) ### ReTurn: Reynaers Aluminium turns waste into resources with new closed-loop systems [](/inspiration/stories/sustainability/closed-loop-systems) Read this [ See all stories ](/stories)