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    Advances in glazing technology means we can now install glass units that boast a thermal performance better than that of standard double glazing, and yet are no thicker than single glazing. In fact, our vacuum insulating glass is so thermally efficient it can even outperform a triple glazed unit. A revelation for owners of period properties that have historically struggled to find an energy efficient alternative to single glass panes that planning is happy to approve.

    Width of single glazing | warmth of triple glazing.

    What do our customers think?

    How does vacuum glazing work?

    Conventional double glazing consists of two glass panes placed apart, with the space between the panes filled with either dry air or an inert gas such as argon. This gas reduces the heat flow through the glass due to its low thermal conductivity. The wider the gap between the panes, the lower the heat transfer, resulting in the overall thickness of double glazing to be no more than 24mm for it to be thermally efficient.

    Vacuum insulated glazing offers a unique approach where the air between the two panes is extracted, creating a vacuum. This means it can offer a thermal performance greater than triple glazing within its ultra-thin profile. A vacuum, no matter how small, is super-efficient at diminishing heat losses via conduction and convection. Unlike traditional double glazing, the gap between the two glass panes can be reduced considerably, resulting in an overall thickness of 6.7mm.

    Why is vacuum insulated glazing so popular?

    Easily retrofitted into existing timber windows and doors
    The super slim profile of vacuum insulated glass means it can be easily retrofitted into all timber windows and doors, allowing the option to retain the original frames if they are in a reasonable or repairable condition. Maintaining the original historic appearance is particularly important to owners of period homes and listed buildings. Until now, these dwellers often needed to sacrifice thermal performance for the sake of protecting the aesthetic appeal of their property. Vacuum glazing eliminates the need for compromise.

    Furthermore, the thin, lightweight nature of the glass (50% lighter than triple glazing), which can be easily installed into existing frames means that no planning permission is required, saving you weeks of time and thousands of pounds going through a lengthy application process.

    Boasts exceptional thermal efficiencies
    It is aptly named insulated glass for a very good reason! In fact, its thermal efficiencies are 8 times more efficient than single glazing and 5% more efficient than a 36mm triple-glazed unit.

    High light transmission
    The higher the light transmission, the more light that comes into your property. Double and triple glazing have lower light transmission values than single glazing because some of the light is absorbed or reflected by the glass. Vacuum glazing lets more light into your property than both double and triple glazing.

    Increasing solar gain
    Heat from the sun warms your home, but the type of glass in your windows and doors can affect this. The more glass you have, the less warmth in your property coming from the sun. Vacuum insulated windows allow the sun to heat your property more than triple glazing and almost as much as double glazing.
    Optimum viewing
    Our vacuum glazing technology has no evacuation port to obstruct the view and has very thin edge seals ensuring maximum vision area.
    15-year guarantee
    Our confidence in this innovative glazing solution is reflected in the long-term warranty we have assigned to it.

    A step towards fighting climate change

    Glazing windows can actually reduce your carbon footprint

    • Declining energy wastage – historically, many period properties are renowned for their inefficient insulation abilities resulting from traditional double-glazing requests commonly declined by local councils. The outdated heating systems generally found in older homes, coupled with incompetent glazing, results in masses of wasted energy. Our double-glazed vacuum units will not only provide the thermal insulation so sought-after by this group of properties, but their acoustic performance will keep them quieter too.
    • They are lead free and 100% recyclable.
    • Zero inert gases – our glazing is vacuum sealed, which means that unlike traditional double-glazing (that has a gas filled space in between two sheets of glass). All the air between the glass sheets is completely removed. The vacuum that is created means it is almost impossible for heat to transfer through it which is what makes it so energy efficient. It also means that unlike double-glazing that needs a noble gas inside of it (which has to be mined, extracted, bottled up, and shipped all over the world). Our high-performance vacuum glazing is an extremely low carbon product to manufacture.

    Made in Britain

    Buying British

    At Wandsworth Sash Windows, we make all our windows, doors, and joinery by hand in our Sussex-based workshop.
    Help us support homegrown craftsmanship and create local jobs – buy British.

    Contact the Wandsworth Sash Windows team

    Talk to us – we can help with your bespoke window, door and joinery requirements. You are very welcome to pop into our showroom, which is based at Unit 2, Kangley Business Centre, Kangley Bridge Road, London SE26 5AQ.

    You can call us on 02079247303 or email