Scientists predict Western Sydney will be hit with around 10 extra days of extreme heat each year between now and 2040. How do we plan for this future?
The impacts of heat are already being felt across Western Sydney as a combination of our natural geography, climate change and green fields making way for new housing developments exacerbate the ‘urban heat island effect’ and extreme heat.
Judith Bruinsma, Project Coordinator, Western Sydney Regional Organisation of Councils
Heatwaves kill more Australians than any other natural disaster. Heat stress affects infrastructure, emergency services, the natural environment and the economy, costing Australia’s economy around $6.9 billion in lost productivity each year.
Across Australia, our urban spaces are heating up as buildings and hard surfaces absorb and radiate heat and as blue and green spaces make way for development. This creates what is known as the ‘urban heat island effect’.
Western Sydney is naturally hotter than Eastern Sydney and is often hit with hot westerly winds and less frequently cooled by sea breezes. Ongoing development means that the region also experiences a higher urban heat island effect than other parts of the city. Residents in Western Sydney consume double the energy for cooling than people in eastern suburbs of Sydney, for instance.
“Much of the focus to date has been on urban greening – but research shows that planting more trees won’t be enough,” says WSROC’s Judith Bruinsma.
While the evidence was clear, the Western Sydney Regional Organisation of Councils, or WSROC, identified the need for tools to translate that evidence into practical action. Bringing together scientists, academics and experts from its member councils, WSROC developed two new resources: the Urban Heat Planning Toolkit and the Cool Suburbs design support tool (soon to be published).
The Urban Heat Planning Toolkit helps local governments to strengthen their planning provisions to reduce the impacts of heat. The toolkit outlines design strategies – from cool roofs to green cover to sustainable water supply – that can help local governments as they plan and design, and also as they support their communities to adapt, survive and thrive in a hotter climate.
“The toolkit looks at the full scale of interventions possible to reduce urban heat and matches those up where local government has a role to play,” Judith says.
Cool Suburbs, developed in collaboration with Resilient Sydney and the Greater Sydney Commission, provides science-backed, practical design guidance to the development industry. With a point scoring system that recognises best practice, Cool Suburbs guides developments from single lots to master planned communities. Cool Suburbs has been tested on real developments in Western Sydney, and governments can use the resource to guide the assessment of development applications.
Both projects recognise that there is no single solution to the urban heat island effect, Judith adds.
“A combination of green space, permeable pavement, cool materials and water-sensitive design must work together. They are all interconnected. In the same way, councils, state governments, industry and the community must work together to adapt, respond and build our resilience to extreme heat.”
Neither the Urban Heat Planning Toolkit nor the Cool Suburbs tool are static. As more people and projects embrace cooling design solutions, and as planning systems adapt to address heat, our evidence base will grow and our tools will adapt and evolve.
Insights for local government
Strengthening local planning provisions can reduce the impacts of urban heat, but this is a new and complex space for local governments. Local provisions can include new standards for building exterior, landscaping and water sensitive design, for example.
“We are already seeing some councils use the toolkit to develop best practice standard clauses for Local Environment Plans and Development Control Plans, by setting targets for green cover, building materials and other measures that mitigate urban heat.”
While local governments can take action to reduce urban heat in their communities, heatwaves will still occur and will become more intense as our climate changes.
“We need solutions that address the urban heat island effect, but local governments also play an important role in building community resilience to heat. These resources help local governments to translate the science into useful strategies that do both.”