Beating the heat: Scientists rate Brisbane's coolest suburbs
As southern Queensland battles its third heatwave in a month, scientists have mapped Brisbane’s coolest and safest suburbs when it comes to heat-related illnesses.
Greater Brisbane’s 5 coolest suburbs
- Karana Downs
- Lake Manchester
- Mount Gravatt
- Bridgeman Downs
It could not have come at a more critical time with temperatures today forecast to peak at 36 degrees Celsius in Brisbane and Logan, and 40C in Ipswich.
On Sunday, Brisbane and Logan are predicted to reach 39C, while Ipswich will hit 43C.
Queensland University of Technology associate professor Adrian Barnett said a lot of people made the mistake of thinking they were tough and could deal with it.
Two previous Queensland heatwaves last month saw nearly 200 people treated for heat stroke and the death of a fit and healthy 30-year-old pilot, Matthew Hall, who collapsed riding a dirt bike on the Sunshine Coast.
Professor Barnett said the coolest suburbs tended to be those with a lower population density.
“[Suburbs] that have a lot of green open space and a lot of blue open space, playing fields, maybe a lake and good air flow,” he said.
“But you can still have a well-ventilated house in a bad suburb and similarly you can still be in a good suburb packed in surrounded by houses and not in the way of any breezes.
“Certainly if you have a great house in a great suburb but are silly enough to have a black roof, your house is going to get a lot hotter than if you had tree shading.
“If the design of the building is bad then it puts people at risk.”
The research project found suburbs with high population density and not much green space meant people there faced a higher risk of heat stroke or dehydration.
Residents in cooler suburbs had a low number of hospitalisations during these hot weather events.
House design key to beating heatwave
QUT engineering expert Dr Wendy Miller said housing design was the biggest problem when it came to “thermal safety”.
She said Queenslanders needed to start “future proofing” their homes against climate change.
But Dr Miller said the biggest hurdle was state regulations, which only required a minimum six-star thermal rating for new houses, on the 10-star rating scale.
“Six stars is based on old climate data from 30 years ago. It is also based on assumptions of what electricity costs back then,” she said.
“Essentially it is a measure of how many hours in a year your house will be comfortable without the need for air-conditioning.
“A six-star house might mean that 50-60 per cent of the year your house will naturally be between 20C and 26C and you will only need to pay for cooling for 40 per cent of the year.
“It is meant in the sense of this is the worst we will allow you to do — not this is the best you should be doing if you really want a comfortable house.”
Dr Miller said six-star homes used three and six times more energy keeping cool compared with a nine-star home, adding more than $3,000 a year to power bills.
“If you get a nine-star house, the percentage of time where the house will naturally be within 20-26C increases to over 90 per cent of the year,” she said.
“A house I went to yesterday to help some people try to be more comfortable was a six-star house and their house was already over 30 degrees by 9:00am and stayed that way until past 9:00pm.
“Whereas my house, which has a 9.5 star rating very rarely gets over 28 degrees. Even now we can get away with a ceiling fan and it costs the same as a project home.”
Dr Miller said it was critical homeowners started to switch their thinking when it came to building, and recommended the Federal Government YourHome website, which offers guidance on environmentally-sustainable homes.
Housing density, materials and colours all contribute to neighbourhood heat. (Supplied: Wendy Miller)
“We tend not to think of our thermal comfort, we look at aesthetics. It’s only in extreme weather we start to think about comfort,” she said.
“We should be building houses that will be comfortable for the next 50 years as we expect to have more heatwaves and more hot days, rather than building to a past climate that was not as extreme.”
Dr Miller said it was essential consumers were made aware of energy efficiency of comfort levels before they bought, built or rented.
New Queensland building regulations are due in 2019.