A HERS index score is basically, a score that shows the energy efficiency of each individual home based on all of its energy efficiency features and the final testing and inspection that comes at the end of the building process. A certified RESNET rater, like LaGrange Consulting, can provide your home with a HERS index, if you so desire. Many national and local programs base their certifications on HERS index scores. Such programs as Energy Star, Builders Challenge and most HUD sponsored building programs all use the HERS index in their certification process. The best explanation of what a HERS index is and how it is calculated can be found at RESNET’s site at https://www.resnet.us/hers-index-score-card