Green Attic

September 29, 2009 6:49 AM PDT

Attic

This is where you can cut your heating and cooling bills significantly. The city of Austin, Texas, which has mandated home energy audits, found that almost 90 percent of the 400 homes audited needed both additional attic insulation and repairs to their leaky ducts.

Low effort: Get an energy audit and help snoop out the places where air from conditioned space (where you live) seeps into your attic, crawl spaces, basement, etc. To find an energy auditor, go to efficiencyfirst.org. There are subsidized weatherizing services for low-income people as well.

Medium: Add more insulation to your attic (and walls). Most homes could use more. Homes in the U.S. should have between R-30 and R-60 insulation. This attic was sprayed with Icenyne foam on the rafters, which provides both insulation and seals the air. The DOE's office of energy efficiency offers a map on what you should have for your climate.

High: Get a comprehensive audit with a blower door test and infrared camera. An audit can cost $500 or $600, but it will help locate air leaks around the house, which is important to do before insulating. Cellulose or fiberglass insulation doesn't stop air flow, it just keeps heat in. To fill those air cracks, learn how to use a caulk gun and canned foam.