How Does Double Glazing Work?

How Does Double Glazing Work

There are many great benefits to having windows upgraded to double glazing but if you are currently considering whether to get double glazing installed, it will help to understand how it works to see exactly how you will benefit.

One of the top benefits of double glazing is the improved energy efficiency it provides, by reducing heat loss and preventing draughts. Older, single pane windows lose a significant amount of heat and therefore cost more in heating bills.

Around 25% of the heat in a house is lost through the windows but having double glazing installed can reduce heating bills by £50 to £175 for the average household per year.

How double glazing works

When the temperature outside of a house is colder than the temperature inside of a house, the heat energy will try to find ways to escape, which is called heat convection. Finding solutions in homes that reduce the speed of heat convection can help to reduce energy bills and having double glazed windows installed is one of the most effective solutions.

The science behind double glazing

Instead of having just one pane of glass in a window frame, double glazed windows have two panes of glass with a layer of argon gas in the space in between. The argon gas layer is integral in preventing heat from escaping, as heat energy needs a good conductor to allow it to move from a hot space to a cold space. 

Glass is a good conductor of heat, so a single pane of glass conducts heat energy and the heat transfers easily from indoors to outdoors. This is why the inner layer, often known as the air gap, is so important. 

The trapped argon gas is a very poor conductor of heat, which is why double glazing performs much higher than single glazing from an energy efficiency perspective. The gap between the two panes of glass is usually between 6mm and 20mm and the wider it is, the more effective it is at reducing heat loss.

The other reason that double glazing is much more energy efficient is due to the frame material. Double glazed windows will usually have UPVC frames or aluminium frames, which are very durable materials that do not wear away. Alternative frame materials such as wood can rot or warp, leading to gaps around the frame where heat can escape.

UPVC is designed to seal tightly around the window so very little air passes through the gap between the frame and the window, limiting heat loss.

Older designs of double glazing are not as energy-efficient as the more modern designs, as technology and research has advanced considerably over the years. Historically, aluminium spacers were used in between the panes of glass, which conducted heat between the panes. The newer designs of double glazing use insulating plastic spacers instead of metal, so that there is very little heat conduction through the layers of the window.

Other benefits of double glazed windows 

Double glazed windows also help to reduce noise pollution, as noise also does not travel easily through the panels of glasses separated by the argon gas. Houses that are on busy roads or have other types of noise pollution will be able to significantly reduce the noise levels by replacing single pane glass with double or triple glazed windows.

Having double glazed windows is one of the few home improvements that is almost guaranteed to add value to your property. When prospective buyers are considering buying your property, they will look at details such as whether the windows have recently been replaced and whether they are double glazed. The valuation provided by the estate agent will also incorporate whether the property has double glazing and how recently they were installed.

Before you sell a property you must order an Energy Performance Certificate which will indicate how energy efficient the property is, based on key details such as the boiler efficiency, home insulation, wall thickness, floor construction and window glazing type. By improving the energy efficiency of a property, you can increase the value of the property and make it a more attractive purchase to buyers.

Another major benefit of having double glazed windows installed is that they provide a higher level of security than single pane windows. Firstly, it is much easier to smash through a single pane of glass compared to double glazing with the air gap. Secondly, the window frames in modern UPVC windows usually have security features such as multi-locking.

The UPVC material and the robustness of the design also is more difficult to prise open than material such as wood, so when you have double glazed windows installed you will be improving your home security.

Double glazing

Get A Quote

Request a free quotation with absolutely no obligation to buy.

Follow us

Contact us

Call us

0800 389 0000

01276 684444

Email us

Open hours

Monday – Friday: 8am to 5pm

Saturday: 9am to 1pm


453 London Road,

Camberley, Surrey,

GU15 3JA, UK