HERS Index – Roxbury E+ Townhomes
Photo courtesy Urbanica
The Home Energy Rating System (HERS) Index is a relative measure of a home’s energy usage and efficiency, where the lower the number, the more efficient and less energy that home uses. According to the U.S. Department of Energy, an existing (older construction) home will score a 130 on the HERS Index, and a typical new construction home will score a 100. A preliminary HERS score is calculated by comparing metrics around envelope and systems for a particular home against a reference home of the same size, shape and exposure, while a final HERS score is established by performing a blower door test, testing duct leakage, checking insulation installation, and confirming any combustion safety concerns.
For more information, see http://www.hersindex.com/.