The average block of land for new homes in Perth is just 399 square metres, the smallest in the country, but the houses are not shrinking as fast.
Data from the Australian Bureau of Statistics (ABS) shows that the average size of blocks of land for new homes has been steadily shrinking around the country for the past decade, and Perth is the first to slip below 400 square metres, to 399sqm in 2021.
The largest blocks are in Adelaide and Brisbane at 468sqm and 459sqm respectively.
Simon Kuestenmacher, director of research at The Demographics Group, told Nadia Mitsopoulos at ABC Radio Perth it all came down to affordability.
"It's also a result of cities becoming denser.
"Perth still has quite a bit of room to grow on the urban fringe, but in the inner city lot sizes get smaller because you can take a quarter acre block, you bulldoze it, and you put three, four, five, or six townhouses on there.
"They have a relatively low footprint."
Houses not shrinking at same pace
The ABS figures show Perth also had the lowest floor area for new builds at 214sqm, down from 229 in 2012.
But around the country, while lot sizes have declined on average by 13 per cent, homes have only shrunk by 1 per cent on average, which means it's backyards that are getting smaller.
Mr Kuestenmacher said research in home preferences showed that while most Australian were willing to compromise on the size of the outdoor area, they were not willing to cut down on bedrooms.
"The demand for more bedrooms is only growing," he said.
"The millennials, the largest generation in Australia, are now reaching the family formation stage of the life cycle, and that means all of a sudden you have millennials leaving the inner cities and small apartments and they want sizeable homes.
"Land is still getting more expensive so we'll probably end up building up more and more in our houses, we will see three-storey townhouses become the norm, probably, in many inner-city locations."
Many listeners to ABC Radio Perth lamented the loss of the traditional backyard.
Geoff: "The loss of backyard cricket is real. There are also no clotheslines which means everyone is using a clothes drier, even in summer, in one of the hottest, driest cities. We've heard all about urban sprawl, but what about urban amenity and high energy consumption?"
Caroline: "How are builders allowed to turn bushland areas into ground zero then stick 10,000 postage stamp-sized houses on there? May as well make high rise apartments and spare as much bushland as possible."
Accelerating divide between rich and poor
Mr Kuestenmacher said that while the loss of the backyard was an issue, Australians should also be more concerned with the quality of new homes that were being built, particularly in terms of energy efficiency.
"If you think about how rich Perth is as a city, how rich Australia is, and then you look at the quality of the building stock that comes online, there is a mismatch," he said.
"We should be living in better, higher quality houses than we currently do.
"But because housing is so expensive we just cut corners wherever we can in order to drive house prices down, and you then make land smaller, and you use cheaper materials."
He said that was likely to fuel further inequality and increase cost-of-living pressures on those people least able to afford it.
"And they will be the first people to be not able to afford to heat or to cool the houses accordingly, and we're just further accelerating the divide between rich and poor in Australia."
