When thinking about the energy efficiency of a new build, there’s plenty to think about. The roof, walls, flooring, and even windows can all let heat escape or absorb it to alter the thermal performance of your home – so choosing the best option is vital. The better the energy efficiency of your windows etc, the more cost-effective appliances and equipment, such as HVAC systems, are.
The most recent changes in the NCC 2022 include stricter requirements when it comes to energy efficiency, and swapping your windows for more efficient ones is a great way to boost the star rating of your new build. Explore why energy-efficient windows are important, as well as much more, below.
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What are the requirements for energy efficiency in Australia?
The beginning of 2024 saw two major changes in the National Construction Code (NCC) – one of which concerns the energy efficiency of new homes and apartments. These must now achieve a 7-star energy equivalence rating out of 10 for the building shell to be compliant with the minimum safety Australian Standard.
The energy equivalence rating can be boosted by the introduction of more efficient walls, windows, floors, and roofing. As your new build will house multiple windows, swapping them out for more efficient options is a great way to boost your rating.
Learn more about the NCC energy efficiency requirements.
Why does your type of window matter?
Energy-efficient windows are designed with innovative framing and glazing materials to minimise heat transfer as much as possible. This means that the heat you want to stay inside will, and the heat you want to keep outside shouldn’t leak through. There are many types of energy-efficient windows to choose from, all being engineered in different ways to keep your home comfortable year-round while also reducing energy costs!
But why does this all matter? Windows can have a huge impact on the heating and cooling abilities of your home, with around 40% of heating energy lost and 87% of heat gained through windows. By choosing energy-efficient windows, you can reduce these margins significantly for either yourself or the new homeowner.
What are the different types of energy-efficient windows available?
There are quite a few types of energy-efficient windows to choose from, including:
Glass windows
It should come as no surprise that glass windows are one of the most popular options to choose from. While the thickness of the glass has minimal impact on the heat transfer through the window, it significantly impacts the safety and strength of the glazing. This may also affect how much noise is transmitted, which can make them more desirable, too.
Double-glazed windows
Double-glazed windows are made from two sheets of glass with a small space between them. This gap is usually 12 mm thick and acts like an insulating barrier which can slow down how quickly heat escapes or enters your home. Double-glazed windows are often considered more energy efficient than glass windows, which only use one sheet of glass.
Triple glazed windows
Triple-glazing windows are considered the superior window insulation choice for most homeowners, as there are three sheets of glass instead of one or two for heat to pass through. Triple-glazed windows help homes stay much cooler in the summer and warmer in the winter, so you can keep the heat in or out without your HVAC system working so hard.
Gas-filled windows
Some windows are filled with gases like argon, xenon, and krypton before being sealed. These gases prevent condensation from seeping in and can optimise the efficiency of the window and its frame.
Window frames
Speaking of window frames, these are also essential to consider when making sure your windows have the biggest impact on your new build’s thermal performance and energy rating. Here are some examples:
- Aluminium frames: Strong, light, and durable, and they come in plenty of powder coating finishes to choose from. However, it’s a good heat conductor which can reduce the window’s insulation value.
- Fibreglass: Durable, energy-efficient and low maintenance, but some people find they’re more expensive than they’re worth.
- Composite: Composite windows are considered more aesthetically pleasing than many other window options, but they’re also heavier which can lead to installation difficulties.
- Wood: Wood can be a good insulator when made from premium materials, and they look amazing. However, more maintenance is required as wood can be susceptible to damage.
How much do energy-efficient windows cost?
When it comes to windows, the number of layers used will greatly affect the price. As a baseline, in Australia, single-glazed Low-E glass prices often start at $185 per square metre.
Double-glazed windows are more efficient and utilise more materials, so they’re bound to be more expensive. Depending on where you get your windows from, they can range in price from $200 to $1,500 per square unit.
If you want to go all out and choose triple-glazing windows, which are the most energy-efficient option, the prices vary even more. Imported windows can cost as little as $150 per square metre, all the way to $12,750 per complete unit.
While double and triple-glazed windows are certainly more expensive, they also add plenty of value to your new build. If you’re planning on reselling after completion, you can increase the asking price and potentially create a bigger profit thanks to the windows alone.
How do energy-efficient windows differ from other windows?
Windows in Australia are assessed by their energy rating, which is decided by the Australian Window Association (AWA)’s independently operated Window Energy Rating Scheme (WERS). Windows that have a WERS label show that they’ve been tested for energy performance and rated on a scale of 0 to 10.
The higher the rating, the better that window will be able to prevent heat loss in winter and heat gain in summer, while also treating the transmission of radiant solar energy depending on what season it is.
By using this 10-star system, you can make an informed decision on how energy-efficient the windows you choose are. While lower-rated windows may be cheaper, higher-rated windows will boost your energy equivalence rating to get it closer to a 7. As your new build will contain plenty of windows, this can be a quick and simple way of complying with the NCC’s new efficiency requirement.
What are the advantages of energy-efficient windows?
The benefits of choosing energy-efficient windows are plentiful, including:
Better insulation
Energy-efficient windows can effectively minimise heat transfer, making sure they insulate your new build properly and keep the temperature within consistent. Homeowners should feel more comfortable within the building as a result, preventing them from having to constantly readjust their thermostats.
Lower energy bills
With improved insulation, windows can save money by reducing energy bills. This is because their thermal performance should keep heat in during winter and out during summer, so homeowners can keep their AC units running hotter and heaters running lower. Over time, many owners find that their energy-efficient windows pay for themselves over time.
Reduces outdoor noise
Energy-efficient windows can also reduce the amount of noise pollution coming from outside your home, making for a more comfortable space inside. This is a great benefit if you’re developing houses or units near busy roads or high-traffic areas so this doesn’t affect your resale value so much.
Less maintenance
Energy-efficient windows are less prone to condensation, meaning there’s a smaller risk of mould and mildew from setting in. This reduces maintenance levels and can improve air quality for the new owners.
Protects the interior living spaces from sun damage
Energy-efficient windows often come with special coatings or glazes that work to block out harmful UV rays, meaning the furniture inside the unit shouldn’t fade so quickly from sun damage. The same can be said for the walls and the flooring.
Are there any disadvantages to energy-efficient windows?
Like most things, energy-efficient windows come with a couple of disadvantages, like:
More expensive for developers
While they’re sure to pay for themselves over time, it can’t be ignored that energy-efficient windows are more expensive for developers and will therefore hike the asking price of the unit up. While you should still be able to get the money back once the unit sells, it can still put your budget out of whack beforehand.
They can trap heat in during summer
If the homeowner opens a window during summer, the heat from the outside will be able to come in and warm up the inside of the unit. Once the window is then shut, the energy-efficient windows can trap this heat in and make the HVAC system work harder to maintain a cooler temperature as a result.
Explore other NCC requirements and regulations you need to be aware of before building a new home
- NCC changes 2024
- NCC energy efficiency requirements
- NCC waterproofing requirements
- NCC floor waste requirements class 1
- NCC handrail requirements
- NCC disability access requirements
Get free advice on your new windows from an experienced building broker
Still wondering whether you need energy-efficient windows, or simply have some more questions surrounding the NCC’s new energy requirements? Our team of Buildi experts are waiting to offer free advice, so get in touch at 1300 947 132 or through our Contact Form today!
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