In the pursuit of sustainable, high-performance buildings, we often find ourselves navigating a series of trade-offs. We want expansive glazing for daylight and connectivity, and trade heat gain against thermal loss. We specify higher-performance triple glazing, but its bulk can compromise design and remove slimmer frame options, while adding weight to building envelopes and opening profiles. An emerging solution is gaining traction around the world which vastly reduces weight and depth and can incorporate slim profiles and offers Passive House levels of thermal performance. It achieves this without the use of inert gasses, no plastics, silicones or butyl rubber, no double reflection and no large-scale face distortion while offering the lowest U values of any insulated glass unit, an expected life span of 50 years plus, no glazing dew point meaning no condensation and resulting in a profoundly lower carbon footprint.
This is the promise of Vacuum Glass, an old concept originally dating back to the 1880’s, finally conceived in the 1990’s and is now, with today’s advancements, the future of insulated glazing. Think of it as a thermos flask envelope for buildings and the true potential will start to register. Where double and triple glazing rely on thick cavities filled with pressurised gas to slow heat transfer, vacuum glass eliminates it using a micro-thin vacuum (from 0.15mm thick) between two panes. This makes vacuum insulated glass the ultimate insulator, effectively removing conductive and convective heat loss.
For any project, this technology will greatly enhance every aspect of design, particularly when viewed through a sustainability lens. It allows you to address both operational carbon and embodied carbon simultaneously.
Radically Reducing Operational Carbon
The thermal performance of VIG is remarkable. With center-pane U-values dipping as low as 0.25 W/m²K (nbs werkman heritage glass), vacuum glass doesn’t just meet modern energy codes; it surpasses them. This level of insulation dramatically reduces the energy demand for heating and cooling your buildings, slashing the operational carbon footprint over the structure’s entire life. It’s a powerful step towards true net-zero design.
The Ultra-Low Embodied Carbon Advantage
This is where vacuum glass truly differentiates itself. As you know, the journey to low operational carbon shouldn’t come at the cost of high embodied carbon. A standard triple-glazed unit is heavy and uses significantly more raw material. Its Environmental Product Declaration (EPD) reflects this.
Let’s look at the numbers. A standard triple-glazed unit can have a Global Warming Potential (GWP) of around 65.9 kg CO₂-eq./m². In contrast, a low-carbon configuration vacuum glass unit can achieve a GWP of just 18.9 kg CO₂-eq./m². That’s a reduction of more than 70% in embodied carbon right from the point of manufacture. Furthermore, leading VIG products are designed without the gasses, plastics, or butyl rubbers found in conventional insulating units, making them fully recyclable at the end of their very long life—often exceeding 60 years.
By specifying vacuum insulated glass, you are doing more than designing a building; you are making a profound commitment to a sustainable future. You are delivering a structure that is lighter, leaner, and kinder to our planet, from its creation to its operation, and offering tomorrows solutions in today’s designs.
Data was sourced from the NBS (National Building Specifications) & OKNA for this article.
