A certified Home Energy Rater assesses the energy efficiency of a home, assigning it a relative performance score. The lower the number, the more energy efficient the home. The U.S. Department of Energy has determined that a typical resale home scores 130 on the HERS Index while a standard new home is awarded a rating of 100. · A home with a HERS Index Score of 70 is 30% more energy efficient than a standard new home · A home with a HERS Index Score of 130 is 30% less energy efficient than a standard new home
To calculate a home’s HERS Index Score, a certified RESNET HERS Rater does an energy rating on your home and compares the data against a ‘reference home’– a designed-model home of the same size and shape as the actual home, so your score is always relative to the size, shape and type of house you live in.