A University of South Australia researcher has called for changes to Australia’s building code in the wake of a study which found newer homes are less resistant to heat than older style brick veneer homes.
UniSA research associate, Dr Gertrud Hatvani-Kovacs, said the building code supported energy efficiency but did not encourage heat stress resistance.
"With newly built buildings that are compliant with the building code they are often over-insulated and have very high air tightness with a lack of natural ventilation and shading," she said.
"The building cannot cool down making the energy efficiency counter-productive. The code should encourage designs that are heat stress resistant."
In a study of typical, single-storey brick veneer homes in Adelaide and Sydney during a heatwave, UniSA research found that newer homes with a 6-star energy rating used the same amount of energy to cool the interior as an older double brick home with just 2.6 stars.
"Building codes need to incorporate separate energy ratings for heating and cooling to give home owners a more accurate assessment of their efficiency," Dr Hatvani-Kovacs said.
"Australians are too reliant on air conditioning. By setting our systems at cooler temperatures we are dumping waste heat to the streets, placing extra demand on the grid, forcing prices upwards and causing more blackouts.
"The solution is to incorporate a range of measures in new homes to deflect heat including lighter and reflective roof colours, and reflective foils installed in roof cavities."
Planting deciduous trees for natural shading, installing outdoor blinds to block the heat and opening windows at night all help to cool a home and minimise the need for air conditioning.