This morning’s Background Briefing on RN examined the flaws in home energy rating systems. The show was unsurprising: they found many houses with low ratings and high performance, and vice versa. No prizes for guessing that architect-designed green homes suffered in the ratings department for not under-glazing, and not air-conditioning. The software wasn’t designed to be used like this and it encourages a conformity of design that suits standard project homes. From my experience, it is a bit of a lottery what the software will think of a custom-designed house.
Paraphrasing Adelaide architect John Maitland in the documentary, the system isn’t good but it’s better than nothing – at least it is pushing the industry along. Maitland designed a house in the early 2000s at Aldinga. An outer skin shields the building fabric from western sun, and a small in-line fan shunts hot air from the mezzanine back downstairs. Both of these are apparently too much for the software to handle. Despite not needing any active heating or cooling (which the software assumes you will have), the house has been rated 4.3, so would be unbuildable today. Its real performance, gauged from energy spend, is closer to 8.0.
This fitting of square pegs into round holes been something architects have grumbled about for years. But now the federal government is planning to extend the rating system to old houses, penalising houses like the one at Aldinga, and thousands more. News is just in that the government has backed off setting dates for the roll-out.
Posted by Peter on 01.04.12 in sustainability