A final score indicating the performance of energy efficiency design and measures in the home as tested by a third-party rater. Points achieved to earn a certification in the GreenVerificationRating field do not apply to this field. HERS Index is most common with new homes and runs with a lower number being more efficient. A net-zero home uses zero energy and has a HERS score of 0. A home that produces more energy than it uses has a negative score. Home Energy Score is a tool more common for existing homes and runs with a higher number being more efficient. It takes square footage into account and caps with 10 as the highest number of points.