Page 14 - Climate Control News Magazine Feb 2019
P. 14

In Focus
A cool approach to urban design
CHEAP CONSTRUCTION THAT RELIES ON AIR CONDITIONING FOR COOLING INSTEAD OF SUSTAINABLE URBAN DESIGN IS UNTENABLE, ACCORDING TO ACADEMICS RESEARCHING THE IMPACT OF URBAN HEAT ISLANDS IN SYDNEY'S WEST.
AS CITY POPULATIONS increase and sum- mer temperatures rise, growing attention is be- ing given to the topic of urban heat islands and what can be done to cool Australian cities.
Urban heat islands are a particular problem at night when grey infrastructure such as roads, carparks, footpaths, roofs and buildings contin- ue to radiate heat long after sunset.
Rapid urban development combined with gen- erally warmer summers in western Sydney means that communities in the west suffer more from urban heat island effects compared to those that live in the east.
Western Sydney University chair of archi- tecture, Professor Chris Knapp, said it is para-
“HIGH DENSITY MATERIALS LIKE MASONRY ARE NOT GOOD INSULATORS.”
– PROFESSOR CHRIS KNAPP.
mount that new construction in the west takes this issue seriously and local councils are proactive in sup- porting and developing sustainable design.
“If not for buildings and infrastruc- ture, we would not have an urban heat island effect, but it is a consequence of how our societies are formed today,” he said.
Some of the most popular design
trends are the very cause of urban
heat increases, according to Professor
Knapp. He said the worst urban design mistakes include dark roofs and unshaded heavy-weight materials such as brick and concrete block.
“They are a real problem as they absorb more heat than light coloured surfaces,” he said.
“Another problem is high-density materials like masonry which are not good insulators; they retain heat very well, meaning they expel and re- radiate heat after the sun goes down.”
Knapp also nominated new homes that don’t feature shading devices or screens.
“They are not positioned correctly to protect inhabitants from the sun, especially in north facing and west facing aspects,” he said.
“Then there are buildings that rely heavily on air-conditioning for cool- ing, rather than insulation and build-
ing design that allows airflow.” Finally, Knapp said another ur- ban mistake is insufficient green- belts and parks between property developments which don’t allow
heat to dissipate.
While plants create microclimates which
cool surroundings and provide shade, he said newly created green areas often feature small plants that don’t provision enough shade.
“We need to design smarter buildings and public spaces that mitigate this issue,” he said.
“Extreme urban heat has significant impacts on public health, energy consumption (through increased air-conditioning use), and has detri- mental effects upon animal behaviour and global warming.”
Dr Sebastian Pfautsch, senior researcher in Urban Ecosystem Science, works with local governments in western Sydney to document base line conditions of urban heat and develop strategies to mitigate its impact.
“Although today even pre-school kids learn about sustainability, the new suburbs built across western Sydney are far removed from this concept,” Dr Pfautsch said.
“No outdoor shade, no cool-roof or cool-street technology, no smart stormwater management, long commutes to work, high degrees of isolation.
“Councils, developers and researchers need to join forces and develop demonstration sites where the public can experience first hand what sustainable urban design looks and feels like.”
Dr Abby Mellick Lopes, senior lecturer in de- sign and lead of the Institute for Culture and So- ciety's Cooling the Commons project, said build- ing and public space design is a crucial element in preparing cities for extreme heat events.
“Cheap construction that relies on air-condi- tioning to the detriment of quality public space is untenable. Cooling is also a community issue,” she said.
Western Sydney University chair of architecture, Professor Chris Knapp
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