How to insulate your home

During the 2019–20 Australian bushfires many of us discovered the ease with which smoke can infiltrate our private living spaces. Given that we spend about 90 per cent of our lives indoors, how can we safeguard our home air from external pollution and be more thermally comfortable without massive expense?

Leaky houses

We’ve all heard of leaky guts. Houses can be leaky too, lacking insulation, and full of gaps, cracks and holes, says Michael Ambrose, a senior experimental scientist with the CSIRO and qualified architect.

“They can lead to enormous amounts of heat loss, particularly if you’re running a heating system, because your house is at positive pressure. If there’s any gaps, out it all goes.”

Prior to 2000 there were no regulatory requirements to install insulation in homes, he reveals. The worst leaky homes tend to be old timber houses on suspended floors. “People that are in old homes would know all about this when it’s a windy day and you can feel the breeze going through,” Ambrose says.

The CSIRO recently measured the leakiness of 125 new Australian homes, using what’s known as a “blower door test”. Essentially, a big fan unit put into the front door of the house