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  • Writer's pictureVishal Saxena

How to choosing the Right Windows for Canberra Weather: A Technical Guide by Hyperspace Architects

Updated: May 14, 2023

When 7 star is to become mandatory in Canberra ?

A Contemporary House as an example in suburb in Canberra or Australia by Hyperspace Architecture
A Contemporary House as an example in suburb in Canberra or Australia

On 1 July 2019, the minimum energy efficiency requirement for new residential buildings was increased to 6.5 stars under the EEIS, as part of the ACT Government's commitment to sustainable building practices.

From 1 July 2022, the minimum energy efficiency requirement for new residential buildings was further increased to 7 stars, making it mandatory for all new residential buildings in Canberra to achieve a minimum of 7 stars under NatHERS to obtain building approvals.

What is ideal or good Uw value and SHGC to get 7 star rating ?

The energy efficiency rating system for buildings in Australia, known as the Nationwide House Energy Rating Scheme (NatHERS), uses a star rating system to indicate the energy performance of a building. A higher star rating represents a more energy-efficient building, with 7 stars being the highest achievable rating a 7 star rating

A Bathroom window Canberra by Hyperspace Architects
A Bathroom window Canberra

U Value (Uw Value) for Windows: Ideally, the U Value (Uw Value) for windows in Zone 7 of Canberra should be below 2.0 W/m2°C, indicating high-quality insulation and minimal heat transfer through the windows.

SHGC Rating for Windows: The SHGC rating for windows in Zone 7 of Canberra should typically be below 0.40 to reduce solar heat gain and improve energy efficiency, especially during hot summers.

It's important to note that achieving a 7-star rating requires a holistic approach to building design and energy efficiency, which includes factors beyond just U Value and SHGC, such as insulation, air sealing, ventilation, and renewable energy systems. Consulting with a qualified energy assessor or building professional can provide more accurate and customized recommendations for achieving a 7-star rating in Zone 7 of Canberra.

Windows play a crucial role in the energy efficiency of a building, and understanding the technical aspects of glazing treatments, frame systems, operations/components, and performance is essential for making informed decisions. At Hyperspace Architects, we prioritize the use of data-driven approaches to ensure that our renovation and new build designs are optimized for energy performance and sustainability.

Windows can be the weak link in achieving high energy rating performance in a house. To give an idea some of the best triple glazing may achieve .8 W/m2°C Uw value rating which translates to 1/.8 = R1.25 value ( Uw = 1/R). A standard bat for walls can easily five R2.5 rating for walls. Thus windows need to be designed in a manner to minimize energy loss in a house.

what are the types of Windows suitable for Canberra region ?

Single glazing : Most of the older homes built right up to 2010 have single glazed windows.

They are single biggest cause for discomfort during both winters and summers. So straight up as Canberrans we should get rid of these

Double glazing : Double glazing started getting affordable since better part of last decade in Australia helping us achieve us better sustainability by lowering our power usage and generally making home more comfortable. Double glazing is basically two glass panes with vacuum or air gap inside which help in insulating the home

The rate of loss of heating from inside is lowered in winters and vice versa in summers.. With better frame technology and fixings its also provides it also helps provide acoustic insulation., so if you live near noisy part of city and are worried about traffic noise double glazing will definitely help.

Triple glazing : Triple Glazing provides next-level heat and sound insulation. It is up to 30-35% more effective than double glazing for thermal efficiency and reduces outside noise by up to 35 decibels. Thus they perform better and along with thermally broken aluminum window and door systems substantially insulate your new home against heat loss and gain.

With Low Emissivity (Low E) coatings the insulating properties can be further improved. At a similar investment dollar; Triple Glazing Thermal PLUS is the obvious choice.

How much more does the triple glazing cost ?

With all this in mind, triple glazed windows can cost around 20-25 % more than double glazing, but the extra cost comes with better performance, so when you look at quality and comfort, you should consider triple glazed windows for the same reason you'd install underfloor heating: it's just better.

Glazing Treatments:

Argon: Argon gas can be inserted between the layers of glass in windows, which slows down the conductance of the air gap, thereby increasing the insulation value of the glazing. This can significantly improve the energy efficiency of the windows by reducing heat transfer.

Low-E Coating: Low-E (low emissivity) coating is a type of glazing treatment that allows beneficial heat from outside to pass through the glass, but reflects it back into the room rather than letting it escape. This coating is often visible as a blue-grey tinge on the glass and can enhance the thermal performance of windows.

Frame Systems:

Aluminium: Aluminium frames are the most common type of window frames but are notorious for their high conductance, meaning they transfer heat easily. This can result in poor insulation and energy inefficiency as the indoor and outdoor temperatures become almost equal.

Thermally Broken Aluminium: Thermally broken aluminium frames have a rubber (polyamide) seal that separates the internal and external frames, reducing conductance and improving energy performance. These frames are more effective than standard aluminium frames and can come in different colors for interior and exterior finishes.

Steel: Steel frames, although less common, offer better thermal performance compared to aluminium frames as steel is four times less conductive. These frames can provide a sleek and modern look with fine profiles, making them a popular choice for contemporary designs.

Timber: Timber frames are known for their aesthetic appeal, but they require high maintenance. However, they offer excellent thermal performance, making them one of the best options for energy-efficient windows.

uPVC: uPVC (unplasticized Polyvinyl Chloride) frames are made of plastic material but offer exceptional thermal performance. Commonly used in Europe, these frames are smooth to operate and have thicker frames and sashes that need to be considered in window design to ensure proportionate aesthetics.


Sliding: Sliding windows have one fixed pane and another pane that slides horizontally. They are a common type of window operation and can be used in various architectural styles.

Awning: Awning windows have a hinge at the top and a winder at the bottom, allowing the window to open outward from the bottom. They are suitable for ventilation in rainy climates as they can be opened even during light rain.

Casement: Casement windows are similar to mini-doors and have a hinge on one side and can be opened with a winder or manually pushed out on the other side. They can be arranged to swing inside or outside and offer excellent ventilation.

Double Hung: Double hung windows have two panes of glass that move independently up or down. They can also come with a moveable bottom hung or top hung, with the other half fixed, offering flexibility in ventilation options.

Tilt and Turn: Tilt and turn windows have a handle on one side that allows for locking, swinging inwards, and tilting inwards from the top hinge. They provide good security and are compatible with honeycomb blinds mounted to each pane, offering a modern and functional window option.

Transoms: Transoms are horizontal bars often used in full height windows where the top portion is a sliding window. They can be fixed and serve as additional structural support.

Hyperspace Architects: Your Partner for Energy-Efficient Windows in Canberra's Climate

If you're planning a renovation or new build in Canberra, a city known for its unique climate, it's essential to consider the energy efficiency of your windows. Windows play a significant role in the overall performance and aesthetics of your project, and choosing the right windows can greatly impact your energy consumption and comfort levels. Hyperspace Architects, a leading architectural firm in Canberra, specializes in incorporating energy-efficient window solutions in their renovations and new builds, ensuring optimal performance in the local climate.

As Canberra experiences hot summers and cold winters, the selection of windows should consider factors such as Solar Heat Gain Coefficient (SHGC) and U-value. SHGC measures the amount of solar heat that passes through a window, with lower values indicating less heat gain. Canberra's hot summers require windows with low SHGC values to reduce heat gain and minimize the need for air conditioning. On the other hand, during cold winters, windows with higher U-values are desirable to prevent heat loss and keep your home warm and comfortable.

Hyperspace Architects as one of the best house designers in the city understands the unique climate of Canberra and can help you choose the right windows for your renovation or new build project. Their expertise in incorporating energy-efficient windows into their designs ensures that your project meets the highest standards of performance and sustainability.

When it comes to window glazing treatments options include double or triple glazing, thermally broken windows low-emissivity (low-e) coatings, and gas-filled insulated glass units. These features significantly improve the thermal performance of windows, reducing heat transfer and improving energy efficiency. Additionally, Hyperspace Architects can recommend appropriate frame systems that minimize heat transfer and air leakage, further enhancing the energy efficiency of your windows.

In terms of window operations and components, Hyperspace Architects can advise on the best options for your project. They can incorporate operable windows, such as awning or casement windows, which offer excellent ventilation and can be strategically placed to capture prevailing breezes in Canberra's climate. Additionally, they can recommend high-quality weatherstripping and hardware that ensures a tight seal, reducing air leakage and improving energy efficiency.

Performance measures are critical in choosing energy-efficient windows, and Hyperspace Architects can guide you in selecting windows that meet your specific requirements. They can recommend windows with low U-values, which indicate low heat transfer and better insulation, and low SHGC values to reduce heat gain during hot summers in Canberra. These performance measures are essential to ensure that your windows perform well in Canberra's climate and help you achieve energy efficiency goals.

In addition to performance measures, Hyperspace Architects can also help you with the design considerations of your windows. They can advise on the style, size, and placement of windows to maximize natural light, views, and ventilation while complementing the overall design aesthetic of your renovation or new build. They can also incorporate shading devices, such as overhangs, external louvers, or shading screens, into the window design to further enhance energy efficiency by reducing heat gain or glare in sunny areas.

Hyperspace Architects recommends windows that have been tested and certified by reputable organizations such as the National Fenestration Rating Council (NFRC) or Energy Star. These certifications provide independent ratings based on standardized testing procedures and ensure that your windows meet the highest standards of performance and energy efficiency.

Furthermore, Hyperspace Architects understands that the design of windows is not just about performance but also aesthetics. They can assist you in choosing windows that complement the overall design aesthetic of your renovation or new build, maximizing natural light and views while enhancing the visual appeal of your project. Their expertise in window placement, sizing, and style can greatly contribute to the overall aesthetics and functionality of your space.

In conclusion, Hyperspace Architects is your trusted partner for designing and specifying energy-efficient windows in Canberra's climate. With their expertise in incorporating high-performance windows into their designs, they can help you achieve sustainable and energy-efficient outcomes for your renovation or new build project. Contact Hyperspace Architects today to discuss your window needs and elevate the performance and aesthetics of your project with energy-efficient windows.

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