A study by a local government sustainability education team in Perth’s southeast has proven that dark roofs and treeless streets make our homes hotter.
The ‘Switch your thinking’ study by the Cities of Gosnells and Armadale and Shire of Serpentine-Jarrahdale used Wi-Fi temperature monitoring, heat mapping and infrared imaging to show how roof colour, home design and urban planning affect temperature in the suburbs.
The research project, funded by the Commonwealth Department of Industry, Innovation and Science, used indoor and outdoor temperature sensors at two similarly built display homes – one with a dark roof, the other a light roof.
Thermal imagery used a visible colour scale to represent temperature differences measured using the infrared sensor equipment.
Dark blue areas had the coolest temperature, red areas had the hottest temperatures, and green areas were in between.
Lead Project Officer, Jessie Parrish, said the thermal drone footage from above a typical housing estate in the Perth suburbs showed a significant difference in temperature between dark and light coloured roofs.
“The effects of climate change are being amplified in urban areas, where dark, hard surfaces such as roofs, roads and pavement are absorbing and releasing more heat energy than light coloured, reflective surfaces and green vegetation – leading to higher temperatures indoors and out.
“Households are spending more money on keeping cool, as well as suffering from increasing negative health impacts due to heat stress.
“It’s important that we find ways to build sustainable homes that keep us comfortable, healthy and are energy efficient.”
In May, ‘Switch your thinking’ held a national webinar on its Cool Roofs project, along with a workshop for Western Australian local governments.
Local governments in other parts of Australia are encouraged to visit switchyourthinking.com/smart-cities to view the project’s drone footage, along with live and historical temperature data from the display homes with dark and light roofs.
