Heat on Developers to Rethink Design

The heat is on developers to “urgently rethink” planning and the use of materials as sensors across Greater Western Sydney tracked big temperature differences in summer.

On Penrith’s hottest day when temperatures soared to 48.9 degrees a difference of 3.6 degrees was recorded between Tench Reserve on the Nepean river and suburban St Marys.

The results were captured from 120 heat sensors placed by Council and Western Sydney University in an effort to determine the relationship between development and urban heat.

Planning was crucial to avoid locking Western Sydney into inescapably high future urban heat according to Western Sydney University senior research fellow Sebastian Pfautsch.

“The process of developing Western Sydney contributes massively to urban heat. And we know how much growth is planned in this area, particularly with the new Western Sydney Airport and associated Aerotropolis precinct,” Pfautsch said.

“Unless we execute this with considerations for urban heat at the very forefront of our planning, 50-degree-plus summers will unfortunately become Western Sydney’s reality.

“The heat difference already measured on 4 January, between Tench Reserve and St Mary’s, is just a precursor of what lies ahead for Penrith.”

Pfautsch said they collected some 46,000 temperature measurements and the main differences were found between locations with green and blue infrastructure and a high proportion of hard urban surfaces.

“Without trees, summer heat becomes unbearable, in new housing estates where you have small blocks almost completely covered by houses with black roofs, it means there is simply no space to grow a meaningful canopy,” Pfautsch said.

“We therefore need to urgently rethink how we plan, build and live, to make more room for green cover and start using smarter solutions like cool roof technology now in the homes and businesses we build.”

Penrith mayor Ross Fowler said it tangibly reinforced how much sustainability decisions in development count in combating urban heat.

“We know anecdotally there can be vast temperature differences across our region, but until now, we’ve lacked evidence to support and correlate this,” Fowler said.

“Collecting heat data this summer will help scientifically inform decision making for our city and tackle rising urban heat.

“Importantly it also allows council to advocate the business case to industry, the community and government, for doing things differently.”

The full results are expected to be released at Cooling the City Masterclass on 18 February with data made available more broadly in mid-2020.