Sustainable housing design and development must come out of the too-hard basket if greenhouse emissions are to be seriously combated. This edition of Eco brings sustainable development home, exploring the issues of housing in a changing climate. Ann White reports.
Image: Lyndal Chase
The recent international Green Cities Conference heard that each resident of Brisbane is responsible for 24 tonnes of carbon dioxide emissions each year, compared with just 5.8 tonnes in Beijing. While many point to large and booming economies overseas, population and housing trends here at home are stark reminders that Queenslanders must look to their own back yards for local solutions to their thumping ecological footprints.
“We have an urgent need for change,” says Mark Thomson, architect and President of the Australian Green Development Forum. “The conference brought home that we will be living in a very different world in 10, 20 or 50 years’ time. We may be experiencing more severe storms, floods and droughts, and we as a community need to start responding to these likely occurrences.”
Currently, most new homes are built by project builders. Buyers choose a standard plan and have it positioned on a site, often with scant attention paid to the principles of “passive design”. The result can be energy-intensive homes which need air-conditioning and heating to maintain user comfort. Passive design uses orientation, layout, materials and the site itself to create a comfortable environment for its occupants with little or no need for artificial temperature control.
“One of the reasons why air conditioning has become so prevalent in southeast Queensland is that our modern houses are so poorly positioned on their sites,” Mr Thomson says. “Regulation is playing a role in improving water and energy efficiency, but to my knowledge there are no moves to regulate passive design in new buildings. It’s in the too-hard basket.”
While the industry is showing signs of change, its efforts are falling short of what is needed. The Housing Institute of Australia (HIA) offers GreenSmart courses in sustainable building and those completing are given permission to use the GreenSmart builder’s logo. However, course completion does not guarantee a builder will change their practices.
“Builders find it easier not to apply good passive design principles,” Mr Thomson says. “The challenge for the building industry is to fully acknowledge passive design and understand its importance in addressing issues like climate change.
“And home buyers need to be educated and empowered to demand it.”
While the basic principles of passive design haven’t changed – orientation of living areas towards the north, a thin building layout ensuring good cross ventilation, using appropriate materials that store heat in winter and ventilate adequately in summer, etc – its site-specific nature makes it difficult to stipulate with the use of standard plans.
Some newer developments are starting to adopt the principles of passive design in their homes and estates, but it needs to consider the wider landscape. Vegetation is a major contributor to a house’s microclimate, however many new subdivisions begin by clearing all trees. Expansive roofs, driveways, high fences and paving can considerably heat the microclimate, contributing to the urban “heat island” effect.
“Maintaining a canopy of shade goes a long way to reducing overheating and maintaining a natural microclimate. Sustainable development needs to look at natural vegetative states for clues as to how we should be designing for the future.”
The Smart Sustainable Home Program is an important step in educating home buyers, says Mr Thomson.
“The houses give visitors an opportunity to experience and learn more about passive design. A majority of people are living with the consequences of poor design and Smart Sustainable Homes give them the chance to see and feel other options.”
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You raise some very interesting points about sustainable housing.
Great article!