A  HERS  Rating for a House is like Miles Per Gallon for a Car

In order for a home to receive a HERS index, an Air Leakage Test is performed to calculate the building's actual leakage. A certified HERS Rater would then model the house using REMRate home energy modeling software. The software not only considers a home's geometry and leakage, but also includes orientation, window size and position, geographic location, insulation levels, appliances, lighting etc. in evaluating it's HERS index. This index qualifies a homeowner for an energy efficient mortgage.

A Hers rater must partner with a Resnet authorized Service  Provider in order to be a part of Resnets stringent  Quality Assurance standards and to authorize the licensing of the  Rating software.  My service provider is the Illinois Association of Energy Raters. We use Architectural Energies Rem/Rate Software