What Is a Home Energy Rating?
Wouldn't it be nice if you could call someone to analyze your home and tell you how it's performing and how it compares to other homes? Well, guess what - you can! That person is called a certified home energy rater, and that analysis is a home energy rating.
The results of the rating include reports covering just about everything you'd want to know about how your home performs. Among other things, you'll find out your home's:
- Annual energy consumption for heating, cooling, water heating, and lights & appliances
- Estimated annual energy costs, broken out into the 4 categories above
- Compliance with energy codes
This analysis can be done for new homes that aren't even built yet as well as existing homes. For new homes, the rater will rate the plans and specifications for the home, which helps when you're trying to make sure the house will qualify for programs like ENERGY STAR or energy efficiency tax incentives or rebates.
For existing homes, a home energy rating can help you come up with a plan to improve your home or to qualify for an Energy Efficient Mortgage (EEM). One way that a rating helps with an improvement plan is by pinpointing where the biggest problems lie. In the graph below, for example, you can see that this home's #1 problem is duct leakage, followed by uninsulated walls and lots of infiltration. Putting a storm door on this house would do little for its efficiency, since heat loss through the door is so small to begin with.
Another nice thing about home energy ratings is that each home gets a score, called the HERS Index. An Index of 100 means that the home exactly meets the energy code. The scale below shows the scale with some markers indicating where different types of houses fall.
RESNET, a nonprofit organization, oversees the Home Energy Rating (HERS) industry. A detailed set of standards (the HERS Standards) governs how certified home energy ratings must be done.
The home energy rating process basically comprises four parts:
- Assessment of building components
- Diagnostic/performance testing
- Energy modeling