Fringe homes not so green: report

Age
31 May 2011, Page: 4

SO YOU thought you had gone green, buying a seven star house with a water tank in a new estate with a sprinkling of gum trees. But it turns out your innercity cousins might still have the edge. New houses on Melbourne's urban fringe are responsible for much greater levels of greenhouse gas emissions than city apartments or high density suburban housing.

Despite the push to introduce six and seven star energy ratings for new houses, the appetite for new household appliances and the increasing reliance on car travel has negated many of the benefits, according to a study from University of Melbourne.

While the operational use of energy in homes has come down because of star ratings, the embodied energy and energy used for commuting to far flung developments has risen, it found. The embodied energy used to make the product in the typical new house has risen more than 400% since the 1950s, mainly driven by the size of the house and the declining number of occupants.

And the average house size has soared, with many new houses well over 200 m², more than double the average in the same period. But it is travel emissions that have ballooned at the greatest rate about 1400%. While Melbourne's suburban fringe in the 1950s was about six kilometres from the CBD Energy, it is now about 35 kilometres away. At this distance, Melbourne's public infrastructure simply cannot keep up, the study's author Dr Robert Crawford said.

Choosing a seven star house was better than a five or six star, but not if the owners lived a "two or three star lifestyle", he said. "When people actually get into their houses and install inefficient heating or cooling systems, or run them all day long, the star system become meaningless".

The study looked at three types of new housing: highrise apartments in Docklands; inner suburban, medium density housing, such as the K2 development in Windsor; and new, outer suburban detached houses. All were more efficient than houses built three years ago (when five star homes were the standard), but energy use in seven star homes was only 13% less than in 2008. High rise apartments were up to 70% less.

Since the start of this month, all new houses have to have a minimum six star energy rating. This applies to the thermal performance of a home, as well as requiring the installation of a solar hot water system or a rainwater tank for toilet flushing. Australia is one of the highest emitters of greenhouse gases in the world on a per person basis.