HERS stands for the Home Energy Rating System. This standard was set by RESNET (Residential Energy Services Network). Here is a brief description of how the HERS Index works in cooperation with RESNET standards.

The HERS Rating Index shows where your home compares with its energy usage, almost like a miles per gallon but for your house. For example, this particular home is sitting at a 65 and the “Reference Home” is at 100. This means the house at 65 uses roughly 35% less energy then the reference home. As you can see, the lower the better.