COOL-LITE® XTREME 51/23 and 51/23 II launched: a new standard in solar control glazing

This high-performance, triple silver-coated, glass delivers outstanding selectivity, processing flexibility and a neutral aesthetic that aligns with modern architectural trends.

COOL-LITE® XTREME 51/23 (annealed) and 51/23 II (to-be-tempered) provide the highest selectivity in the XTREME portfolio, combining a light transmission of 51% with a remarkably low solar factor of just 23%. This results in a selectivity of 2.22, allowing more natural daylight to enter while effectively managing solar heat gain – a critical balance for creating liveable, comfortable spaces, even in highly glazed buildings. The product helps improve both visual and thermal comfort, supporting building performance without compromising on aesthetics.

The launch introduces the first annealed version of this specification to the XTREME range, giving fabricators, architects and specifiers greater design flexibility. Both versions deliver identical performance and visual qualities, regardless of whether the glass is tempered or not. The to-be-tempered COOL-LITE® XTREME 51/23 II version also comes with EASYPRO® surface protection, making handling and processing simpler, cleaner and more sustainable – saving time, reducing waste, and supporting energy efficiency in production.

A key feature of this new product is its refined, modern appearance. With a neutral colour tone, low exterior reflectivity and consistency across all viewing angles, COOL-LITE® XTREME 51/23 (II) was developed to meet the most demanding architectural ambitions. Whether used in façades, curtain walling or glazed roofs, it offers a sleek, contemporary look that complements a wide variety of building styles.

Supporting the building industry’s shift towards more sustainable solutions, COOL-LITE® XTREME 51/23 (II) is available on PLANICLEAR® standard float glass, DIAMANT® low-iron glass, and ORAÉ® low-carbon glass. The availability on ORAÉ® makes it possible to specify a high-performance solar control solution while reducing both operational and embodied carbon, helping projects meet increasingly stringent environmental targets without compromise.

This new product will replace the outgoing COOL-LITE® XTREME 50/22 II, offering improved aesthetics and, for the first time in this performance category, an annealed version to complement the to-be-tempered option. It joins the existing COOL-LITE® XTREME family, including 70/33 (II) and 61/29 (II), and will be manufactured in Saint-Gobain’s high-tech facility in Germany with the same reliable supply, availability and service that UK customers have come to expect.

With the launch of COOL-LITE® XTREME 51/23 and 51/23 II, Saint-Gobain Glass continues to push the boundaries of what is possible in architectural glazing – delivering solutions that combine technical excellence, design flexibility and sustainability. This latest innovation demonstrates the company’s commitment to helping its partners in the building industry meet the evolving demands of modern construction, from energy performance to aesthetics and environmental responsibility.