Why are Australian homes so cold and can we warm them up in an affordable way?

Much of Australia is having a cold snap right now — with sub-zero temperatures in six different states and territories.And it can be very nice in those times to curl up in a warm room with a hot cuppa, and forget about the world outside.Unfortunately, many Australian homes barely keep the cold outside, and that affects our energy bills, which are already high.Professor Emma Baker discusses what can we do to warm up our homes - both this winter and into the future?