Andrew Merry/Getty Every winter, millions of Australians are reminded how hard it is to live comfortably in older homes. Warm air constantly leaks out through poorly insulated ceilings, walls and floors, and through gaps in floors, windows and under doors. Heaters run day and night, sending energy bills soaring. The gap between new and old homes is huge. Since 2004, new homes across most of Australia have to meet minimum energy performance standards. Homes now have to reach 7 stars on the natio