Double glazing costs: will the extra pane pay off in the long run?

Deputy Editor · 26 September 2019

An ongoing financial dilemma for many homeowners is the cost versus benefit equation of certain improvements and additions around the house. Will you be adding value? Will possible long-term savings eventually outstrip upfront costs? Whether or not to install double-glazed windows is one example.

If you’re looking to make your home more energy efficient, block out some external noise and potentially make your property more secure, double glazing your windows and doors could be an option worth considering. But will your eyes glaze over when you hear the cost? Let’s find out.

How much do double-glazed windows cost?

Double-glazed windows and doors are most commonly priced by the square metre. According to, the average cost of newly-fitted double glazed windows is around $1,350 per square metre, based on quotes submitted to the site in 2018. In some cases, the cost can also be quoted on a ‘per opening’ basis, with the total cost determined by how many windows and doors are being fitted. ServiceSeeking estimates that retrofitting is approximately 10% to 20% more expensive than custom-made double glazing.

If you only need the glass installed, and not the frames, says you can expect to pay upwards of $200 per square metre for double-glazed glass and $220 per square metre for a low emission option. On top of that, you would likely need to separately factor in the cost of the glazier which could be between $70 and $90 per hour. If you need emergency repairs carried out, this could cost up to $150 per hour.

While the average cost might give you a general idea of how much you may need to spend, the exact cost of double glazing can depend on an almost endless range of variable factors, making specific prices difficult to arrive at without having an installer visit your property. Speaking to Canstar, Mitch Hartley from Ecostar Double Glazing summarised some of the key factors that can determine price as follows:

  • The type and specification (thickness, tinting etc.) of the glass
  • The material used for the window frame
  • The colour of the frame
  • The window opening style, including the details of any handles or similar mechanisms
  • The style of architraves and reveals used (the materials around the window frame)

Mr Hartley explained that the type of building the windows are being added to, and therefore the difficulty of the installation, can also determine the cost to the homeowner. In particular, the distance of the windows from the floor and what level of the house they’re on (ground floor, first floor etc.) can impact the difficulty and cost of the job.

→ Renovating a home could change what insurance cover you may need:  Compare home and contents insurance providers.

What are the options to finance double-glazed windows?

How you finance the work may depend on how much it costs. There are several options available for would-be home renovators to consider, including:

Home loan: If this job is big enough, or you are doing a range of jobs at the same time, one choice you may consider is refinancing or restructuring your home loan, or adding a “line of credit”. For example, depending on your lender you may be able to add a redraw facility to your existing loan (although it’s wise to keep in mind that some fees could apply to any loan changes and there could be redraw limits). Or, you could add an offset account, which could help reduce the interest paid on your loan while still allowing access to your money (although it’s wise to keep in mind there could be some fees involved here, too, and higher interest rates could apply to these types of loans).  Compare home loans with Canstar.

Personal loan: Depending on your personal circumstances and the cost of the job, you may consider using a personal loan to fund the work. This could be a secured loan, or an unsecured loan. It’s worth keeping in mind, though, that interest rates are generally higher for personal loans than for home loans, and it’s a good idea to read the lender’s terms and conditions first. Compare personal loans with Canstar.

Credit card: It may also be possible, depending on the cost and your ability to repay the debt quickly, to pay for the job on a credit card. There could be some fringe benefits for doing so, such as extra insurance cover in some cases (read the card’s Product Disclosure Statement to find out the conditions of the cover). Keep in mind that credit card interest rates are typically much higher than home or personal loans, and interest can quickly accumulate on large balances, so it is a good idea to weigh up your options and consider them carefully. If you don’t think you’ll be able to pay off the card’s balance in full each month, it may be worth re-considering whether a credit card is the right option for you. Compare credit cards with Canstar.

If you’re currently comparing credit cards, the comparison table below displays some of the low interest credit cards currently available on Canstar’s database for Australians looking to spend around $2,000 per month. Please note that this table features links direct to the provider’s website, and is sorted by Star Rating (highest to lowest), followed by provider name (alphabetical). Use Canstar’s credit card comparison selector to view a wider range of credit cards.

What are double-glazed windows?

Double-glazed windows differ from traditional, single-glazed windows by using two separate pieces of glass separated by an airtight space that acts as a form of insulation. According to specialist provider, Next Generation Glass and Double Glazing, different types of glass can be used in double-glazed windows to suit the needs of the homeowner, but the materials used are generally similar to those employed in single-glazed windows. There is also such a thing as triple-glazed windows, but it’s more commonly used in colder parts of the world, such as Europe.

Double glazed window cross view
Source: ElRoi (Shutterstock)

Generally speaking, double-glazed windows can be added to a property in one of two ways:

  • Custom-made double-glazed windows: these are produced and installed as a single unit made up of two panes of glass. This approach is commonly used on the windows and doors of new houses and extensions, where the building work is being done from scratch.
  • Retrofit double glazing or secondary glazing: this is where an additional pane of glass is added to an existing single-glazed window on a property. This is referred to by some in the industry as ‘Frankenstein glazing’ and is sometimes used when an existing home is being renovated.

How to save on the cost of double-glazed windows?

While it’s unlikely to be a cheap undertaking one way or another, you may be able to save some money on the cost of adding double-glazed windows by making some savvy choices along the way.

Mr Hartley suggests homeowners should think carefully about colours and window style in particular.

“Cost-conscious consumers generally go for lighter colours and simple openings. In terms of style, they usually go for awning or casement windows,” he said.

Open Awning windows in a blue wall
Awning style windows. Source: Ratchat (Shutterstock)

According to, you may be able to reduce the cost of adding double-glazed windows to your home by doing some of the work yourself, such as by measuring, ordering and purchasing the materials for the window and then simply paying for someone to fit them. 

But even this preliminary work is likely to require a degree of knowledge and skill, so it could be worth thinking carefully about the risks of getting stuck in yourself, for example by getting the measurements wrong or buying the wrong type of window.

Looking at other saving options, the Australian Government’s Department of Energy suggests that homeowners can also consider lower-cost alternatives to double glazing, such as laminating products that you can attach to your existing windows.  

And of course, regardless of which insulation technique you choose, there’s the age-old method of getting bang for your buck simply by shopping around for the best-value supplier. If you get a number of quotes from different companies, you might be surprised at how their prices vary. Just make sure you’re comparing apples with apples, i.e. the same kinds of glass and frames etc.

What are the benefits of double-glazed windows?

Some of the potential benefits of adding double-glazed windows to your property, as outlined by window supplier Ecovue, can include:

  • Energy efficiency: The sealed air between the panes of glass act as a form of thermal insulation. This is designed to lock in the cool air in your house in summer and stop heat escaping in winter. It could mean you’ll be using your heater and air conditioner less, with a reduced power bill as a result.
  • Noise reduction: As well as keeping cold or hot air out of your home, double-glazed windows can also help to shut out more external noise than their single-glazed equivalents. Consider checking with your installer about the optimal set-up for your windows, as the distance between the two panes of glass that maximises sound reduction may be different to the gap that works best for heat insulation.
  • Prevent mould forming indoors: Particularly in the more humid parts of the country, double glazing may help reduce condensation on the inside of the windows and help prevent mould from developing in your home. 
  • Safety and security: According to Ecovue, double-glazed windows are harder to break than normal windows. They may be particularly effective if coupled with other security measures for your windows and doors.
Builder installing window pane
Source: Dmitry Kalinovsky (Shutterstock)

What are the disadvantages of double-glazed windows?

Some of the potential drawbacks of installing double glazed windows could include:

  • The upfront cost: While they could potentially deliver energy savings in the long run, double-glazed windows can come with a significant installation cost – potentially 25% to 35% more than the cost of single-glazed windows, according to hipages. You would also have to consider the potentially higher costs involved if your double-glazed windows need to be replaced in the future. Also consider how the installation would impact on other features of your windows, such as blinds or shutters that are already installed.
  • Style fit: It may not always be easy to find double-glazed windows that fit with the style of certain properties, particularly older ones, as double glazing tends to be a more modern style of window. However, retrofitting your existing windows may be an option that would mean certain elements of your existing window frames remaining in place and retaining their original style.
  • The added weight: If you’re installing double-glazed windows on an existing property, particularly an older building, Mr Hartley says that the increased weight of the extra pane of glass could cause the materials around the window to warp out of shape over time. This could potentially create draughts and cancel out any increased insulation that the window itself might provide.
Double glazing older style windows can be a challenge. Source: Lenart Gabor (Shutterstock)

Can double glazing save you money on energy bills?

One of the main potential benefits typically associated with double glazing is the impact it can have on your home’s energy efficiency, and the potential knock-on effect on the amount you spend on your energy bills.

When calculating any potential energy savings, it could be beneficial to remember the number 40.

  • Your home can lose up to 40% of its heat through its windows (it can also gain up to 87% of its heat through windows)
  • Heating and cooling can account for about 40% of your energy use
  • By properly insulating and draught-proofing your house, you can reduce your heating and cooling bills by up to 40%

Source: Government of South Australia Department of Environment and Water.

Put another way,, an Australian manufacturer of windows and doors, estimates that the addition of double glazing to a standard house could deliver a $200-250 saving per year on energy bills. 

However, any actual savings specific to your household would depend on factors such as the size of your home, the quality of the double glazing and the climate where you live, and of course how much your annual energy bill is to start off with.


Image Source: Tarapong Srichaiyos (Shutterstock)


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