Neighbourhoods feeling the heat as medium density housing robs suburbs of street and garden trees
University of South Australia Media Release
New housing subdivisions, smaller yards and a dependence on air conditioning have resulted in a 30 per cent decline in Australian residential trees in the past decade, leading to hotter neighbourhoods and increased energy costs.
The dramatic loss of suburban trees has led to UniSA environmental researchers calling for new national planning policies to mandate the inclusion of trees in any development or housing design.
Qualified architect and UniSA PhD candidate Mina Rouhollahi says a recent study of 90 Australian residential suburbs shows tree-inclusive gardens and yards provide up to a 30-metre buffer around each land unit during summer heatwaves.
“Deciduous trees, in particular, provide summer shade, while their bare branches allow heat to penetrate into the house in winter,” Rouhollahi says.
“Local government focuses on public parks and urban forests but it’s the residential trees that make a significant difference to home energy costs. Also, private land tree planting provides a better environment for children, improving urban aesthetics and increasing home values.”
Rouhollahi and her UniSA colleagues, including supervisor Professor John Boland, have designed an optimal tree strategy for different housing configurations, nominating specific tree types, tree volumes, and correct placement to achieve maximum benefits.
Their strategy is outlined in a new paper published in Energy and Buildings.
It incorporates all seasons and microclimates, allowing planners, developers and designers to adopt the tree options that suit specific environments.
Their research recommends five optimal tree arrangements depending on deep soil availability and space.
“We need a more cohesive urban planning approach to compensate for residential tree loss in recent decades and regulate heat as well as curb energy costs,” Prof Boland says.
The researchers’ proposal aligns with the latest IPCC report, recommending increased space between houses to allow for more trees, as well as utilising reflective building materials. The report says taking these steps could significantly decrease urban heat, reduce the reliance on electricity, and thereby cut blackout risks.
A major challenge, however, is to change Australians’ attitudes, increasing the focus on home energy efficiency through appropriate tree planting, double glazing and better house design, moving away from air conditioning reliance.
“Australians have the power to influence the design process, requesting tree allocation when building or buying their home, in the same way they insisted on a double garage in the 1990s. The focus has shifted to boosting our wellbeing and the role that trees play in this,” Rouhollahi says.
“Redesigning our homes with trees in mind will better serve residents, cities, and the environment. Trees have numerous benefits: they shield us from the sun, provide wind protection, reduce stormwater runoff, passive cooling and natural ventilation. The net result is a more energy efficient home, lower energy costs, reduced air conditioning, CO2 emissions and less polluted air.”
Current residential development policies rely on public and communal open spaces to compensate for the lack of trees in private yards. Yet, this does not provide energy savings, the researchers say.
The researchers hope their recommendations, outlining different optimal tree options, will be adopted by local councils and embedded in their planning policies.
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11 comments
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Lawrence Roberts -
Michael Taylor -
leefe -
Michael Taylor -
Caz -
leefe -
margcal -
John Boland -
TuffGuy -
Michael Taylor -
Michael Taylor
Return to home pageWhere possible and applicable all new developments should plant trees suitable for koalas. Traffic conditions adjusted to suit safety.
Lawrence, Carol – as a former shire councillor – is adamant that the biggest winners out of medium or high density housing are the developers.
No eaves, dark rooves … it’s almost like they’re trying to make the buildings as energy inefficient as possible.
leefe, a bit off topic, but I must tell you this story.
In my ATSIC days I went to the Umoona Aboriginal community (near Coober Pedy, SA) to inspect some new houses. The architect (from Queensland) was meeting me there.
Having him roll up in a white safari suit – with a tie – was bad enough, but I had the horror to notice that in the driest state in the driest continent he designed houses that had no gutters.
When I asked him why the houses had no gutters for water collection he responded; “If the black kids throw rocks on the roof they would have rolled into the gutter.”
I kicked his arse so hard that I think he might have had trouble sitting down for the next month.
Racist prick.
I live in the inner city with lots of terraces and traffic. But we also have lots of trees, big ones too and lots of little parks. The parks are important as back yards are tiny. At night even everyone is ready for bed I go out with my dog. All I can smell is the trees.. The roads are quiet and I tell myself that I live in the best part of Sydney. Not a McMansion in sight.
Michael:
#NotAllQueenslanders, and yet …
Architects are a strange breed. I could drag the conversation even further off topic with a few more horror stories, but best not.
The “development” industry gets away with murder like no other industry at all.
Rules? They’re for getting around, and they do.
Where is the money trail?
If we need to employ people in construction, why can’t it be via public service departments building public housing, schools (repair, replace, new), hospitals (ditto), more train tracks – in Victoria replacing and restarting country lines closed by Kennett, and more?
Re architects – If there’s a pile-on, I’m in!
Michael
Goodonya for kicking the architect!!
Here in Canberra high density housing is the biggest issue. Everywhere you look buildings and houses (on big blocks or groups of houses together) are being torn down to build multi-storey apartments. Not only are they destroying the heritage of Canberra as the bush capital they are just plain ugly, not to mention also the traffic and parking problems they cause.
Developers are getting super rich because councils and local governments are giving them what they want, for who know what sort of kick-backs. These will be the slums of the future.
John, my lecturers at UniSA taught me to be tough and to take no crap from anyone.
TuffGuy, went back to to Canberra a couple of years ago and almost cried when I saw how the planners had stuffed-up my old areas of Nicholls and Ngunnawal, as well as Palmerston. They need to change the name of the Gungahlin area to Townhouse City.