Reglazing single glazed windows with vacuum glazing

Installing vacuum glazing into existing sashes & frames

The main issue with single glazing is heat loss – let’s fix that

If you struggle to heat your house in the winter without worrying about energy bills, the single glazing of your windows is likely a major contributor to this issue.

Due to the large glazing surface of windows, especially in Victorian-style houses where windows can be around two meters tall, heat escapes straight out of the house through single panes as thin as 4 mm, or sometimes even 3 mm.

The thermal image bellow shows how much heat is lost through single-glazed windows.

The bright areas highlight significant energy inefficiency, where warmth escapes from your home, making it harder to maintain a comfortable temperature and increasing energy bills.

Converting single glazing windows to double glazed

The vacuum glass we use in our reglazing projects is not too think yet just as effective as triple glazing at protecting your home from thermal changes.

This below thermal image demonstrates the effectiveness of vacuum double glazing in reducing heat loss.

The darker areas suggest significantly less heat escaping the house.

Comparing the efficiency of single glazed windows and vacuum-sealed glazing

U-value is the rate at which heat transfers through a structure or object is measured. So, the walls of your home have a U-value, and so do your windows.

The lower the U-value, the better the windows are at stopping heat from entering or leaving your home.

Single-glazed windows have a U-value of around 5 or 6.

The double-glazed units that we retrofit into your existing window frames have a U-value of 0.4 Landvac to 0.7 FINEO glass, depending on the chosen brand.

This is the same U-value as most modern triple-glazing units, estimated to achieve A-rated windows efficiency.

Vacuum insulated glazing options

As an independent VIG glass installer, we are not affiliated with any vacuum double glazing factories.

We act in the best interest of our customers’ budgets and project requirements, offering a wide range of vacuum-insulated double glazing options.

We work with all major brands of VIG insulated glazing, such as Fineo Glass and LandVac, as well as more niche brands.

If you’ve never heard of vacuum glazing, here’s how it works

Now, you’re probably thinking, “this sounds too good to be true”, right?

Let us help you understand how this technology differs from standard double glazing on a theoretical level.

The cavity in vacuum-insulated glazing is filled with a vacuum instead of gas. As you may remember from school physics, a vacuum barely transfers energy, making it the perfect insulator.

It’s simple: the two panes of glass have a tiny vacuum cavity with low energy conductivity, making the entire glazing unit energy efficient.

Other benefits to vacuum-sealed double glazing units

It reduces external noise, prevents internal condensation, and improves security.

Alternative to full window replacement

Our sash window restoration services are the perfect way of bringing your wooden windows into the 21st century.

We use the highest quality materials and window technology to ensure that your windows look just as amazing as they always have.

But with additions like retrofitted double glazing and modern draughtproofing, they are just as effective as uPVC triple-glazed windows without changing the style of your home at all.

Suitable for the window in Grade 2 listed historic properties

All of the window restoration services we have spoken about on this page are suitable for grade 2 listed properties.

You’ll need to seek planning permission for the work, but based on our experience, most of the applications for reglazing original windows are approved by conservation officers.

The reason why conservation officers are more in favour of reglazing is that it saves original frames and only changes glass.

Draught-proofing is done alongside reglazing

During all of our window restoration projects, we want to ensure we protect your windows in every way possible.

This is why we provide rot treatments on the timber and splice in repairs wherever needed.

During reglazing, our team installs modern draughtproofing seals to seal the gap between the sashes and frame.

This is important because a 3-4 mm gap can let a lot of heat out, and it does not make sense to change the glass but not to seal the sashes properly.

Preserve period windows and save money

The last thing anyone who owns a period home wants to do is change the charming exterior forever.

New uPVC windows can greatly change the appearance of your home, and for many listed buildings, changing wooden windows for uPVC isn’t allowed. The replacement of identical wooden windows in some cases can be allowed, but it will be extremely costly.

Single-glazed window reglazing is the best way of bringing your window technology into the 21st century without changing the look of your home at all.

It can save you loads of money on full window replacement costs and your energy bills too.

FAQs