The lower a home’s HERS Index (Home Energy Rating Systems), the more energy efficient it is. A home built to code scores a HERS Index of 100, while a net zero energy home scores a HERS Index of 0. Each 1-point decrease in the HERS Index corresponds to a 1% reduction in energy consumption compared to the HERS Reference Home. Thus, a home with a HERS Index of 85 is 15% more energy efficient than the reference home and a home with a HERS Index of 80 is 20% more energy efficient.
HERS testing and scoring is administered by an organization called RESNET (Residential Energy Service Network). This link will provide more information about the organization, the process and the raters.
723 Spring Street scored in the 40’s which means that the home uses approximately 60% less energy than a Code built home. A 40 on the E-scale reflects a savings of $1616 per year relative to a typical existing home and $1078 relative to a typical new home.In addition to being less costly to operate, the home is quieter, cleaner, and more comfortable. This exceeds the minimum index required to meet the DOE Energy Star for Homes Standard. This low HERS Index also contributed significantly towards the LEED Platinum Certification, making 723 Spring Street one of the greenest and most energy efficient homes in Ann Arbor.