Homeowners seeking to improve their property's energy efficiency are increasingly presented with a high-tech alternative to traditional double glazing: vacuum glazing. This innovative solution promises superior thermal performance in a much slimmer frame, but it comes with a significantly higher price tag.
What Exactly is Vacuum Glazing?
Unlike standard double glazing, which uses a cavity filled with an inert gas like argon to reduce heat transfer, vacuum glazing creates a sealed vacuum between the two panes of glass. This vacuum, containing no air or gas molecules to conduct heat, acts as an exceptionally powerful insulator, operating on the same principle as a thermos flask.
The result is a window that is remarkably effective at keeping warmth inside during winter and maintaining cooler indoor temperatures in summer. A key advantage is its slim profile. Because the vacuum provides the insulation, the units can be noticeably thinner than conventional double-glazed units while still offering high thermal performance. This makes it an ideal solution for period properties or homes with narrow window frames where maintaining the original aesthetic is a priority.
Cost and Practical Considerations
The major drawback is undoubtedly the cost. Creating a perfect vacuum within a sealed glass unit is a more complex and expensive process than filling a unit with gas. According to specialist fitter Six Over Six, vacuum glazing costs between £340 and £390 per square metre, excluding VAT and delivery.
This stands in stark contrast to regular double glazing with a low-emissivity coating, which costs between £30 and £70 per square metre, as reported by fitter Eco Happy. When factoring in the total cost of a new window—including frames and labour—opting for vacuum glazing could easily increase the overall price by 50% or more compared to a standard uPVC double-glazed window, which can cost under £600 fully fitted.
Is Vacuum Glazing the Right Investment for Your Home?
Both vacuum and double glazing typically last between 10 and 25 years, depending on the quality and maintenance. While vacuum glazing is technically superior in terms of insulation, its high cost currently limits its widespread adoption outside of specialist applications.
For many homeowners, triple glazing may offer a more balanced alternative, providing enhanced performance at only about 15% more than the cost of double glazing. The decision to invest in vacuum glazing ultimately hinges on whether the savings on future heating bills will outweigh the substantial upfront cost. This calculation depends on factors like your home's size, window dimensions, and other energy efficiency measures already in place.
It's also worth noting that super-efficient windows provide limited benefit if a home suffers from significant heat loss through draughts or poor loft insulation. For those with older properties where slim-profile glazing is the only viable option, or for whom budget is a secondary concern, vacuum glazing represents the cutting edge of window technology.
