What is a Home Energy Rating?

A home energy rating involves an analysis of a home’s construction plans and onsite inspections. Based on the home’s plans, the Home Energy Rater uses an energy efficiency software package to perform an energy analysis of the home’s design. This analysis yields a projected, pre-construction Energy Rating Index. Upon completion of the plan review, the rater will work with the builder to identify the energy efficiency improvements needed to ensure the house will meet ENERGY STAR performance guidelines. The rater then conducts onsite inspections, typically including a blower door test (to test the leakiness of the house) and a duct test (to test the leakiness of the ducts). Results of these tests, along with inputs derived from the plan review, are used to generate the Energy Rating Index score for the home.

The Energy Rating Index

The Energy Rating Index is a scoring system established by the Residential Energy Services Network (RESNET) in which a home built to the specifications of the Energy Rating Reference Home (based on the 2006 International Energy Conservation Code) scores a Energy Rating Index of 100, while a net zero energy home scores a Energy Rating Index of 0. The lower a home’s Energy Rating Index, the more energy efficient it is in comparison to the Energy Rating Reference Home.

Each 1-point decrease in the Energy Rating Index corresponds to a 1% reduction in energy consumption compared to the Energy Rating Reference Home. Thus a home with a Energy Rating Index of 85 is 15% more energy efficient than the Energy Rating Reference Home and a home with a Energy Rating Index of 80 is 20% more energy efficient.

For more information, visit the RESNET Web site Exit ENERGY STAR.