Everything you need to know about Double Glazed Windows and How they Work

As a first home buyer or DIY renovator, it can be difficult to know exactly which decisions will impact your property in the long-term. In our 30 years of operation, we’ve often found the most confusion when it comes to choosing fittings, as the materials and glazing you choose can have a big impact on the planet, and your wallet.

One of the most common questions we get asked here at Dee Glass is whether double glazing is really worth it in comparison to single glazed windows. “With an extra 30% upfront cost, how do I know this will really save me money in the long run?”

The answer depends on a whole range of factors, so if you’ve ever been curious about what double glazed windows are, the prices of double glazing or the long-term benefits in comparison to single glazing, the following guide to double glazing can help you decide.

What are Double Glazed Windows?

Double glazed windows are made with two panels of glass, and a vacuum of air in between. The hollow frame that holds this vacuum of air (referred to in the industry as a spacebar) is usually around 6-16mm thick, with the total window thickness usually between 18-28mm.

Spacebars are most typically made from aluminium as it is a cheaper, lighter and more malleable, however you can opt for a “warm edge spacebar”, which is expensive yet more energy efficient. By filling the spacebar with dehydrated air or other inert gases** and sealing it so it’s airtight, double glazing can help keep your home at a comfortable temperature.

**Inert gases like Argon, Krypton and Xenon, are often used in replacement of air as they have a much lower thermal conductivity. Argon, which has 34% lower thermal conductivity than air, is the most common option as Xenon and Krypton are very expensive. If you’d like to know more about the specifics, give us a call on (02) 4934 1466

How do Double Glazed Windows Work?

The best way to describe how double glazing works is to think about the vacuum of air or inert gas between the panels as a speed bump, slowing down the penetration of hot or cold air. This speed bump, created by the layering of the glass panels and vacuum sealed air gap, reduces the impact that hot or cold air has upon the second panel of glass, keeping the air inside your home in, and the outside air out.

This layering also stops those annoying cold and hot spots that you can often feel in summer or winter near single glazed windows. These spots are not only frustrating but have a large impact upon your energy bills, making your air conditioning system work twice as hard to keep the room at a constant temperature.

Single Glazed Windows v Double Glazed Windows

As energy bills rise and road noise increases, double glazing is becoming a popular option for new home buyers and renovators.

There are both advantages and disadvantages to single glazing. It’s much cheaper option at the outset, with single glazed windows costing 30% less, but they do not have the ’speed bump’ stopping the infiltration of hot or cold air inside your home. This means they can be up to 20 times less efficient in keeping air in than the walls they’re built into!

Why choose Double Glazed Windows?

#1 Energy Efficient

It’s no secret that your house is an energy consumption monster, and with the constant price hikes in energy bills, it’s only logical to consider improving the energy efficiency of your home. Both for your wallet and the planet.

Double glazing can stop around 35% of heat loss in winter and around 10% of heat gain in summer compared to a single glazed window. This means you may not won’t need to use your air conditioner or your heater as often as you would in a house with single glazed windows (yourenergysavings.gov.au)

#2 Reduce Noise

The vacuum of air in the spacebar of double glazed windows absorbs not only the hot and cool air trying to come in, but sound waves as well. Double glazing significantly reduces noise from busy roads, loud neighbours, trains and buses.

This makes them particularly useful for homeowners with properties that back onto freeways, or apartment owners living above busy bars or shops on main streets. Dependant upon the glass used in the windows, and the double glazing thickness, noise can be reduced by up to 70% in some scenarios.

#3 Higher Market value

Double glazed windows can dramatically reduce your carbon footprint and your energy bills, as well as ensuring any unwanted noise is considerably reduced. These factors, alongside the fact that your home is kept at a comfortable temperature all year round, often ensure your property will have a much higher value than those with single glazed windows.

What will they cost?

Double glazed window prices can vary widely depending on a variety of factors. When you start shopping for double glazed windows you’ll find the following factors can affect the prices:

 – The material of the window frame
 – The type of glazing used
 – The size of the installation
 – The thickness of the glass
 – The type of spacebar

The cost of double glazing can vary greatly, from $200 per square metre to $800 per square metre, but you can usually you can expect to pay at least 25-35% more for a double glazed window than a single glazed window.

Are Double Glazed Windows Worth it?

In our opinion, the decision is an air-tight YES (see what we did there?) However, as with all major purchase decisions, it’s important to learn exactly what works for your home, as each and every one is different!

Be sure to take note of the windows that receive direct morning or afternoon sunlight, or windows that face noisy, busy roads, and mention this to your glazier when you decide to make the switch. If you’d like to speak to one of the team here at Dee Glass, just give us a call on (02) 4934 1466