Energy Star Efficiency Ratings for Homes

In the early 1990s, the U.S. established the Energy Star standard to measure the energy efficiency of buildings. The rating system for homes, new or previously built, is called the home energy rating system (HERS) index.

HERS Inspectors

• A certified HERS index inspector must conduct the HERS index inspection. Certified inspectors are listed with the Residential Services Network.

Digital Readout

• The house will be inspected in every detail from the roof to the foundation. Calculations are complex and determined digitally because the inspection is extremely detailed and involves many variables.

The Relative Index

• HERS evaluations begin with a geographically specific baseline. Estimators review data on the average household energy use per square foot in the same region and base the rating on that average. For this reason, the HERS index is called a relative index.

150 or Below

• Average local use is assigned the number 150. A hypothetical house that uses no energy would get a rating of zero. Your house will receive a number of 150 for use that matches or exceeds the local average. The lower your number, the greater your energy efficiency.