Answer:

An energy rater is someone who has been trained and certified by an accredited Home Energy Rating Provider to inspect and evaluate a home’s energy and performance features, prepare rating documentation and make recommendations for improvements that will save the homeowner energy and money. Home Energy Rating Providers include RESNET (Residential Energy Services Network) and BPI (Building Performance Institute). Heretofore, RESNET standards have mainly applied to new buildings through the Energy Star program. (Both Earthcraft Virginia and LEED for Homes are built upon this program, although they are concerned with more than energy efficiency). BPI has emerged as the leading Provider for comprehensive existing building assessments performed to identify ways to improve building performance, safety, comfort and value. RESNET and BPI are in the midst of finalizing a mutually beneficial joint standard agreement to address the needs of the existing homes market. Earthcraft Virginia’s programs relies upon HERS and BPI-certified raters. Earthcraft Virginia is also a certified Provider for LEED for Homes qualified auditors.

Energy Star bases its rating system on RESNET’s ‘relative energy use index’, called a HERS (Home Energy Rating System) index. A certified HERS rater has been accredited by RESNET to operate performance testing equipment, conduct thorough visual inspections, operate accredited energy and performance modeling software and make recommendations to homeowners. Accuracy of HERS rater work is itself annually audited through independent quality assurance field verification. The primary focus of RESNET has been to provide ratings for new homes.

BPI trains and certifies building auditors to serve not only the weatherization industry, but also the growing residential and multifamily building performance contracting industry. Their primary focus is analysis for existing buildings. BPI works with building performance industry stakeholders, such as Energy Star and Earthcraft Virginia, to ensure that the professional bar for excellence in building performance contracting is established and maintained by creating and regularly updating technical requirements.

See "What is the relationship between BPI and RESNET?" for more information about the new RESNET/BPI joint standard. – Monica Rokicki-Guajardo