The "hazardous" heat of Sydney's western suburbs
A Sydney academic is advocating the city combat dangerously overheated suburbs by building town houses and apartment blocks instead of single family homes.
That would mean more room for green infrastructure to cool temperatures down, says Dr Sebastian Pfautsch, an expert in urban heat and senior research fellow at Western Sydney University.
Dr Sebastian Pfautsch.
He told Radio New Zealand’s Kathryn Ryan that urban sprawl in Sydney’s outer west meant residents were regularly battling temperatures up to 15 degrees hotter than other parts of the city.
“I had six locations in western Sydney last summer that were at or above 50 C which is half way to boiling point,” Dr Pfautsch told the Nine to Noon host. “People really have to realise what that means.
“Fifty degrees is very, very hot. In some parts of the world - particularly Scandinavian countries, you may use that as a sauna temperature. So this is something that you use temporarily for a few minutes to enjoy and after that you jump into ice cold water.
Unshaded asphalt carparks are a massive source of heat in cities and Dr Pfautsch’s research has shown that there are 6 km2 of this type of “hideous space “in Western Sydney. Image credit: Dr Sebastian Pfautsch.
“But people have to roast in these kind of temperatures for hours. Sometimes if heatwaves last longer, and the predictions are for even more extreme and more lasting heatwave conditions in this part of the Sydney basin, then you see two or three consecutive days of temperatures of these extremes.”
He said they were partly due to geographic reasons but also because of human-influenced conditions like a lack of green infrastructure, the type of building materials used in houses and building design. Previously he’s estimated that 80 percent of the surface area in western Sydney is sealed with roads, pavements, car park buildings and other kinds of construction that trap heat.
These images show the impact of different roof colours on surface heat. Image credit: Dr Sebastian Pfautsch.
And he says black roofing iron, single glazed windows and a lack of insulation kept houses hot, meaning residents didn’t cool down, even at night.
“This is not the Australian dream, it’s the Australian nightmare because we are really creating conditions that are hazardous for the next decades where ... we know it’s only going to be hotter.
There are easy things to change, and also very difficult things to change, Dr Pfautsch says in relation to solutions.
Easy examples would be to ban black roofs - something Los Angeles did a decade ago. Use double or triple glazing on windows, good thermal insulation and consider moving away from open plan living so that it was easier to cool smaller spaces down.
Typical development in Western Sydney where houses occupy nearly the entire block, not leaving space to plant and grow a tree for shade. Also, the suburb is deprived of any meaningful green infrastructure, roof colours are generally dark, houses are massive. Image credit: Dr Sebastian Pfautsch.
“A little bit more difficult would be to try and convince people not to build to the maximum extend on their blocks and allow more open space. So we don’t need a house with 250 or 200 sq metres of floor space, maybe 120 to 150 is enough and on your smaller block that may be about 300 or 350 sq you can have more open space which allows to build shade into your property.”
“Then we’re getting into the space of regulation, more stick, less carrot for developers, where you really have to prescribe how your suburb has to look. You’re looking into what we call heat-smart density so you’re moving away from single dwellings for each family but you’re looking more into town houses, apartments and starting to build up into towers, 25-30 stories high.”
Dr Pfautsch says then instead of having houses “until the horizon” there would be one very dense centre embedded in parklands that are then the space where communities have their shared neighbourhood for parties, walks, picnics and exercise.
He warned that with another 800,000 people expected to settle in Sydney in the next 15 years the western suburbs were the only place for them to go because of space and affordability.
“Working towards heat-smart density will provide us with opportunities to rethink what the Australian dream should really look like, in a time where we know that climate extremes are increasing, where we know that urban green infrastructure is increasingly important.
“The Government here in New South Wales is flushing millions of dollars into programmes to green the city. Even politicians realise how important it is that green infrastructure is now provided throughout the city for cooling… and all the additional benefits you get with public health, walkability, active transport, biodiversity.
“We have no chance to reach these goals if we continue with business as usual, building these flat and wide new suburbs with materials that are heat absorbent with no space left to add green infrastructure for the next decades, and we have to provide alternatives.”