HERSThe Home Energy Rating System (HERS) Index is the industry standard by which a home’s energy efficiency is measured. It’s also the nationally recognized system for inspecting and calculating a home’s energy performance.

How the Score is Determined

HERS is a scoring system set by the Residential Energy Services Network (RESNET) to measure a home’s energy efficiency and determine if it meets ENERGY STAR guidelines. The lower the HERS Index, the more energy efficient the home.

Who determines the HERS Score?

A third-party certified HERS Rater audits each home during multiple stages of construction to identify its energy characteristics, such as insulation levels, window efficiency, wall-to-window ratios, the heating and cooling system efficiency, the solar orientation of the home, and the water heating system. Performance testing, such as a blower door test for air leakage and duct leakage, is also part of the rating.

Why use the HERS Index?

You wouldn’t buy a new car without knowing how many miles per gallon it gets. Why should buying a home be any different? Think of a HERS score as the MPG rating for your home.
Outside of your mortgage, the highest cost of homeownership is ENERGY. With home energy costs climbing, it only makes sense to find out how energy efficient a home really is.

See this fact sheet for a pdf version.