A typical knock-down rebuild in Sydney's suburbs is wiping out nearly half the front garden and more than 60 per cent of tree canopy, according to new research from Macquarie University .
Driveways are also expanding – up 57 per cent – as larger houses and double garages increasingly dominate suburban streets.
The study examined hundreds of redeveloped homes across Northern Sydney and Greater Western Sydney, finding the overall size of front yards declined by about 19 per cent, while gardens were increasingly replaced by paved surfaces.
Professor Peter Davies, lead author of the study from Macquarie University's School of Natural Sciences, said the shift reflects both changing lifestyles and planning settings.
New dwellings in Sydney are losing greenspace.
"By world standards, Australians build the some of the biggest houses and as a suburban nation, we rely on our car to get around," he said. "The consequence is more space dedicated to the house and car and less to the garden and the urban canopy."
The findings raise concerns about urban heat, biodiversity and liveability in Sydney's suburbs, as current development trends move in the opposite direction of the state's urban greening ambitions.
The study suggests the NSW Government is missing its target for 40 per cent urban canopy cover across Greater Sydney, with building projects leading to reduced tree canopy on residential blocks.
"We are sleepwalking ourselves away from a green suburban aesthetic to one dominated by buildings and driveways," said Davies. "If all knock-down rebuilds ideally retained or at least planted a tree in their front yard, we would be well on our way to a greener Sydney."
