Australia has a star rating system, administered by the Federal Government, known as NatHERS. Stars sound very clear and positive. However, there is a bit of confusion about the star ratings produced by NatHERS.

Importantly, NatHERS assumes something that is virtually never tested. The NatHERS scheme has the long title “Nationwide House Energy Rating Scheme” and its website is administered by the Department of Industry, Innovation and Science. Many people will know that 6 stars is the minimum requirement for new houses, and that…