Why choose double glazing?

Written by Super User

In this month’s news piece we explain what double glazing is, how it works, the advantages of having it installed in your home and what types of double glazing are available.

What is double glazing? Double-glazed windows consist of two panes of glass with a layer of air or gas between them. In contrast, single-glazed windows have only one pane and no gap. How does it work? Double glazing works as an insulator in much the same way as a cavity wall. Having two panes of glass doubles the amount of glass that heat has to get through but the main insulating power is from the air gap. It is a poor conductor of heat and therefore keeps warm air trapped inside your home.

What are the advantages of double glazing? ‬‬‬‬‬‬

Double glazing has many benefits over single glazing. Replacing or upgrading your windows can improve:

Energy efficiency

Double glazing was introduced to keep warm air in, meaning your home is better insulated. Modern high quality double glazing now has sophisticated glass coating technology, high specification sealants and spacer bars and the presence of argon gas (an inert gas) between the two pieces of glass, which all substantially reduce the loss of heat from inside the room. This means fewer draughts, a warmer home and lower heating bills.

It is important to note, however that effective glazing is only part of the solution to fully insulating your home. Roofing, flooring and wall insulation will also be major drivers of energy efficiency.  

Noise insulation

Sound travels through the air in waves. The waves decrease in intensity as they move away from the source of noise. A good analogy to visualise sound waves is to imagine you throw a stone into a pond, the ripples get smaller and less impactful as they move away from where that stone hit the water. Sound is measured in decibels (Db). The higher the Db the louder the sound.

Correct installation of good quality double glazing units can lead to a noticeable reduction in noise levels inside the home. There are two vital components to this, however: the thickness of the glass and the air gap between the glass. Domestic windows are typically 4-6mm thick. It follows that the thicker the glass, the better the noise insulation but it is also important to note that different glass thicknesses reduce different noise frequencies. So, if your double-glazed unit has one pane of glass at 4mm thick and one at 6mm thick, this will reduce noise across a wider frequency range than if they were the same thickness.

To get the maximum benefit from your double glazing, the gaps between the panes of glass should be 16mm and the gap between the two glass panes should be filled with argon gas, which adds another layer of heat insulation. If the gap is reduced then the thermal performance is reduced, unless you use a very expensive gas such as krypton.

Internal condensation

Double glazing reduces the amount of condensation on the inside of your windows.‬‬ Single-glazed windows do not retain any heat and so have a lower temperature, essentially the outside air temperature. This allows moisture in the room to condense on the cold surface. By comparison, the inside layer of a double-glazed windows maintains a higher temperature, which stops the condensation forming.


One of the main ways an intruder gains entry to a property is by breaking the glass in the windows or doors. Double-glazed windows provide extra security not only because two layers are much harder to break than one but also because they have their own locking system. At E W Grace Glass we can provide safety glass – either toughened or laminated glass. The preferred option to prevent entry is laminated glass. We also use burglar proof locks and hinge protectors to further enhance security.


Double glazing can also enhance the appearance of a property. The frames come in a range of types and colours and can be designed to match traditional frames if you live in an old property. Double glazing is also an attractive feature to most buyers should you choose to sell your home in the future.

What types of double glazing are available?

Frames for the glass are typically made from unplasticised polyvinyl chloride (UPVC), aluminum or hardwood. UPVC has better insulating properties than aluminum, but aluminum may be more aesthetically pleasing, particularly for older properties.

Of course, double glazing is not the only option. Depending on your property and your requirements, triple glazing and secondary glazing are other routes to discuss with your glazing company. Watch out for future blogs on these products!

Perhaps you have just moved into a period property and you need to replace rotten or heat inefficient windows but retain the look or meet planning requirements, or perhaps you feel it’s time to replace or windows or doors in your existing home. Whatever the project, please feel free to talk to us about it. We are always happy to provide advice or a free consultation.


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 Contact Details

Address: E W Grace Glass
28 High Road
Buckhurst Hill
Essex IG9 5HP


020 8505 5656
020 8559 0714