That, he says, is between 15 per cent and 25 per cent of the average running cost of homes in the state.
It costs money to save money. The three-bedroom homes on The Cape estate on Bass Coast sell for $330,000 and the four-bedroom ones go for just under $400,000.
This is up to $11,000 more than an equivalent dwelling built to standard energy efficiency ratings. But Condon estimates the annual saving of about $2500 per year means a four to five-year payback time to recoup the extra outlay.
It's a clear sign that the market for homes with an average energy efficiency rating of 8 stars (which consume half the energy of a 6 star-rated home) has moved into the mainstream.
"Over the past 10 years, the cost of electricity has doubled," he says.
"Gas costs are up 50 per cent, solar panels have reduced 80 to 90 per cent in price and the efficiency of these new home operating systems has increased so much that the financial performance of sustainable homes has passed conventional homes like ships in the night.
"The important point is that the volume builders can follow our methods to achieve similar reduced premiums for building sustainable homes compared to their normal homes."
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