Energy efficiency: how does your house rate?

Want to avoid big power bills in your next home? The federal government wants all homes for sale or rent to have an energy efficiency rating. We already rate new homes, and the system is weeding out some power guzzling designs. But there are major flaws as well. Some super efficient designs don’t rate—and some six star homes are still substandard. So how do you find an energy efficient home? Reporter: Di Martin