Have you ever heard of cool roofs? A new study from UNSW Sydney has found that adopting cool roofs across major Australian cities could reduce heat-related mortalities, lower indoor temperatures, and minimise our power bills, too!
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What Are Cool Roofs?
Cool roofs are essentially roofs that reflect more solar radiation than they absorb, like a mirror! These reflective surfaces stay cool in sunlight, which is why UNSW Sydney investigated the applicability and cost-benefit of using cool roof technology across Australian cities.
The study investigated the climatic, social, economic and environmental impacts of implementing cool roofs around Australia. The researchers looked at 17 types of buildings — ranging from low to high rise, commercial to residential, stand-alone, and apartment blocks. They found, if the whole of Sydney implemented cool roofs, energy consumption for cooling residential and commercial buildings would decrease by up to 40%. All in all, indoor temperatures in residential houses would be reduced by up to 4 degrees celsius.
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Which Australian Cities Will Gain The Most From Cool Roofs?
Results have shown that urban areas, including Western Sydney, Perth, Melbourne, Adelaide, Darwin and Brisbane, had the most to gain from cool roofs,” said Professor Santamouris.
A building in Western Sydney, for example, requires more than double the energy to cool down compared to a building in Eastern Sydney. “Western Sydney is especially at risk of urban overheating, meaning the low-income households are more likely to either spend more on cooling or are forced to endure heat-related stress indoors. It’s a very serious problem,” he said.
The cooling benefits aren’t just for singular buildings, either. The city-scale use of cool roofs could actually lower the peak outdoor air temperature by up to 2.5 degrees celsius!
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As Our Cities Warm Up, Cool Roofs Must Be A Priority!
So, considering all the benefits of cool roofs, why isn't it common all throughout Australian cities? Sadly, a lack of legislation and policy support is holding back the implementation of cool roofs across Australian cities.
According to the researchers, if cool roofs were widely implemented across Australia, it could create more than 150,000 jobs. It could save lives, too! “Cool roofs can reduce heat-related mortality by up to 25-30%. They will also help address energy poverty — an issue severely impacting the quality of life of low-income households,” said Santamouris.
With our climate continuing to heat up, the need for cool roofs and other heat mitigation technologies should really be a priority. “If not, the cost of climatic change in the next 10 to 15 years will be tremendous,” he said.
In the future, we’d love to see the widespread adoption of cool roofs across all major Australian cities. As our cities warm to extreme temperatures every summer, cool roofs may help to keep our cities cooler, protect our vulnerable people from extreme heat, and minimise our power bills!
We also thought we'd mention the importance of isolation in buildings too. There's no need to reflect solar energy if the cool or warmth from inside the building escapes easily. Just something to keep in mind when it comes to cool roofs.
If you love hearing about sustainable and energy efficient cities, keep an eye on our Eco News category for more stories!
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