A home energy audit (or survey) evaluates an existing home to determine where and how energy is being lost, what systems are operating inefficiently and what cost-effective improvements can be implemented to enhance occupant comfort, make the home more durable and lower utility costs.
RESNET has defined three types of energy assessments for existing homes which range in complexity from a simple but effective walk-through survey to a performance audit using diagnostic equipment and computerized data analysis to a comprehensive home energy rating utilizing the most sophisticated modeling software to produce a home rating score on the HERS Index.
A Comprehensive HERS Rating is the most in-depth performance audit of an existing home. It consists of the evaluation, diagnostic testing, cost-effective recommendations and work specifications contained in a Building Performance Audit.
In addition, a Comprehensive HERS Rating includes a computerized simulation analysis utilizing RESNET Accredited Rating Software to calculate a rating score on the HERS Index. The report will also contain a cost/benefit analysis for the recommended improvements and expected return on investment. Comprehensive HERS Ratings of existing homes will be required to qualify loan applicants for certain federally sponsored mortgage products.