Aerial photo exposes 'serious problem' with new Aussie homes branded 'slums of the future'

Dark roofs and other surfaces are contributing to the urban heat problem, experts say.

Carly Bass·Senior News Reporter
Updated Wed, 6 March 2024 at 2:16 pm GMT+7·5-min read

New housing developments on the outskirts of major Australian cities are the "slums of the future" according to built environment expert Paul Osmond who says urban heat in emerging areas is a "serious problem" that needs addressing now before it's too late.

The abundance of dark surfaces like concrete, asphalt and roofing, with a lack of trees and open spaces, is contributing to record-high temperatures in already-scorching suburbs, including parts of western Sydney which has previously been the hottest place on earth in the midst of a summer heatwave in 2020. Alarmingly, new housing in areas like these is being designed to retain heat, rather than stay cool.

It's now becoming "unsustainable" and is a matter of "human health," the UNSW professor told Yahoo News Australia saying "we don't have time to play around". Hotter temperatures due to poor planning will soon enough have a detrimental impact on lives — and darker roofs, often seen on new homes and chosen for their aesthetic appeal, are partly to blame, he warned.

Left: An aerial photo of a housing development at Manor Lakes, Melbourne showing black roofs. Right: Established housing in the suburb of Blackburn showing plenty of trees.
New housing development in Manor Lakes, Melbourne shows a sea of black roofs compared to the established suburb of Blackburn. Source: Reddit
Dark roofs 'absorb' heat, making suburbs hotter
Aerial photos shared online recently show a housing development in Manor Lakes, west of Melbourne — a sprawling new suburb now home to 9,500 residents. Almost every house features a black or dark-coloured roof, which according to Osmond, is now a common sight sweeping new-build areas.

Lighter colours "reflect the heat back to space" whereas black or darker colours "absorb" it. "It's not a theory, it's just physics," he explained. "It contributes to what's known as the urban heat island effect".

In built-up urban areas that contain dark materials, and other built materials, like concrete, which absorb heat, Osmond said "there's less evaporation, less transpiration from plants – both of which cool an environment".

"All of these things coming together are creating a hotter environment in those new developments".

... Nearmap analysis found that substantially more suburbs in greater Adelaide have seen a loss in residential tree canopy than have gained tree canopy.

Over the past decade:

Half of Adelaide suburbs lost at least 9.8% residential tree cover

Overall relativeresidential tree cover fell by 8.6% (20.1% in 2011, to 18.3% in 2021)

Specifically, 131 suburbs (of 281 suburbs) have lost at least 10% residential tree cover

Specifically, 18 suburbs (of 281 suburbs) have seen an increase of at least 10% residential tree cover.
...