Large, expansive windows are becoming a common design flaw in Australian apartments, according to experts in the field.
For Llewellyn McGarry, the search for an energy-efficient, accessible dual-occupancy home for herself and her mother led her to an apartment that seemed perfect on paper. Located in the southern part of Canberra, this property offered stunning sunset views of the nearby mountains. Moving in during the colder months, Ms. McGarry was pleasantly surprised to find that the floor-to-ceiling windows helped keep the apartment warm during winter.
However, as summer rolled in, the situation took a drastic turn, with indoor temperatures soaring above 40 degrees Celsius. "It was astonishing to realize it reached 42 degrees here at 5:50 PM," her mother, Marie, remarked. "We never anticipated how hot it would become. With a concrete structure, double glazing, and various features that suggested comfort, we thought we were safe—but the heat was unbearable."
The Design Dilemma
As climate change continues to bring about hotter summers and increasingly frequent heatwaves, experts argue that it's crucial to rethink the living conditions of apartment residents. In a groundbreaking study—the most extensive of its kind conducted in Australia—researchers are monitoring the indoor temperatures, air quality, and usage of windows and air conditioning across 450 apartments in Sydney, Melbourne, and Queensland over two years. The goal is to gain insights into how apartment inhabitants use energy and maintain their comfort levels.
During a recent heatwave, the research team, led by senior research scientist Pippa Soccio, conducted surveys among participants to gauge how comfortable they felt in their homes. The findings revealed that 25% of respondents reported feeling warm or excessively hot, primarily due to insufficient air movement. Dr. Soccio noted, "Very few participants had ceiling fans. While air conditioning can effectively cool our homes, what happens during a heatwave when there's a power outage, and you can't rely on it? Are you able to open your windows? Can you facilitate airflow, especially when a cool breeze finally arrives?"
Other factors contributing to the uncomfortably high temperatures in these apartments included insufficient shading, ineffective air conditioning systems, or personal choices not to utilize air conditioning altogether.
Window Issues
Ms. McGarry's predicament is not an isolated case; many apartment residents across Australia are enduring oppressive heat each year, even though their buildings adhere to established construction standards. The unexpectedly high indoor temperatures were particularly puzzling for Ms. McGarry, who had assumed that her double-glazed windows with dark tinting would act as a barrier against excessive heat. "I believed double glazing would help with heating, cooling, and noise reduction, but as soon as the sun hits the surface, it actually feels hotter inside than outside," she explained. "If you touch it, it’s scorching. It feels like it could burn you."
Building scientist Peter Lyons pointed out that, depending on the climate, the choice of glazing can be a balancing act between preventing overheating in the summer and enhancing warmth in the winter. "When you have large glazed areas, particularly those facing west without any shading, those windows absorb a tremendous amount of solar heat," he stated. "You may benefit from that solar energy during winter, but the drawback is that it becomes a significant liability in the summer months."
This design flaw is a recurring theme in Australian apartment buildings, as highlighted by the CSIRO's Apartment Energy Behaviour Study. "There's a prevailing belief that more glass allows for increased access to natural light, which is often preferred over artificial lighting," he commented. "However, depending on the orientation of the building, more glazing can also lead to greater sunlight exposure, resulting in increased radiant heat that can warm up the apartment significantly."
Dr. Soccio added, "Using glazing to frame a view can be beneficial, but capturing an entire view with glass may not be the best approach."
Limited Solutions
To combat the heat, Ms. McGarry has installed internal blinds set to lower in the afternoons when the sun hits hardest. Additionally, she has added accordion-style blinds with reflective backing in the bedrooms. While these measures have provided some relief, Ms. McGarry still finds the temperature uncomfortably high. Even with the air conditioner set to a chilly 19 degrees Celsius, the temperature rarely dips below 24 degrees. "It’s an improvement compared to my mother's situation, but it’s still sweltering—30 degrees just this past Monday," she stated.
Her monthly energy bills have skyrocketed to $300, far exceeding her expectations, and this expense is critical for her well-being, given her health condition. "As someone who struggles to regulate my body temperature, anything above 24 degrees Celsius is extremely uncomfortable, making me feel quite ill," Ms. McGarry shared. "We aimed for a long-term solution, a forever home that would cater to both my needs and my mother’s... But it’s simply too hot."
While observing the new developments surrounding them, Ms. McGarry and her mother reflect on the future for potential residents in apartments filled with glass walls. "These unfortunate individuals will experience the morning sun on one side and the afternoon sun on the other, essentially baking all day long," Marie McGarry lamented.
