A home energy assessment or energy audit is an inspection of a home to determine how to make it more energy efficient. Some audits are more thorough and detailed than others, depending on the service provider, and fees vary greatly as a result. Keep this in mind when you are deciding whom to hire to perform your audit. Ask for details about what is included in the audit, so you can compare apples to apples.
Most building performance experts agree that “the house as a system” approach is the best way to conduct an audit. Professionals who subscribe to this method use building science when they evaluate a house. They understand that a home’s structure, equipment, lighting and appliances all interact, and that each affects the other. For example, a home with top-of-the-line, high efficiency heating and air conditioning equipment, could still be inefficient if certain structural deficiencies are present, such as insufficient insulation or leaky ductwork. “The house as a system” approach enables these auditors to be good detectives when it comes to finding the cause of a problem. It also prevents them from doing harm; creating or worsening problems in one part of the house when they correct a problem somewhere else. BPI certified Building Analysts and RESNET certified Energy Raters have received training in building science and “the house as a system.”
A whole house assessment usually begins with an inspection of the exterior of your home. The architectural style of your home can provide the auditor with clues as to where to look for potential problems. You also can help by providing copies of your energy bills and a list of any problems you’ve noticed, including those that relate to your own comfort. Excessive dust, drafty rooms, musty smells, visible mold or mildew, and temperature variances from room to room are some of the things that can be indicative of specific problems.
The auditor should inspect every room of the house as well as your crawlspace and attic. He or she should test any naturally drafting combustion appliances, such as a gas powered water heater, to make sure they are functioning in a safe manner.
An auditor also may use diagnostic tools such a blower door to test the tightness of the structure, a duct blaster to test for leaks in your ductwork and an infrared camera to check insulation and detect air leakage.
When the assessment is complete the auditor’s recommendations may include the following:
- Adding insulation
- Sealing air leaks
- Sealing ductwork
- Upgrading appliances and HVAC equipment with energy efficient models
- Replacing incandescent light bulbs with compact fluorescent bulbs
- Installing solar water heater
Ask your auditor about state and federal tax incentives and rebates for energy efficiency improvements. He or she should also be able to help you prioritize the improvements in terms of what will give you the most bang for the buck.
The web sites of the Department of Energy, ENERGY STAR and Progress Energy all have handy tools to help you do your own home energy assessment.