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Home Energy Ratings and Your Home

  • Posted: 02.24.2020
HERS index scale

The Home Energy Rating System, commonly referred to as HERS, is the best way to ensure that the energy efficiency of a new home or retrofit is as great as what you—and your builder—expect. A good rating can also provide a higher home value, ensure that your home will be comfortable for your family to live in and offer lower utility bills each month. You may also be able to garner a special mortgage.

For Iowa consumers, it’s also one of the least known check-ups during the building and remodeling process. That’s because there are very few certified HERS raters in our state, perhaps only about 20 of them statewide, according to Roger Hammen, energy advisor for Iowa’s Midland Power Cooperative. However, he says, “If I were building a home for my family, I’d want it to be HERS rated. I’d work with my builder to find a rater. It’s definitely worth the extra few hundred dollars to get the peace of mind that all systems are working together correctly as they should.”

What is a HERS rating?
The HERS index is a standard way to measure the energy efficiency of a home. It is nationally recognized so that if you plan to buy or sell a home, you will know exactly how efficient the home is by looking at the score. That knowledge gives everyone involved—the buyer and sellers, the builder/remodeler, appraiser, realtor, and even your loan officer—the peace of mind knowing the home is what it claims to be: energy efficient.

A HERS rating will identify any construction problems and improper equipment installation. The rater will run various tests to check details about:

  • Exterior walls
  • Floors, ceilings, roofs, attics, foundations
  • Windows and doors
  • Vents and ductwork, HVAC systems, lighting, appliances, water heaters
  • Air leakage

The HERS rating provides a score of how those systems work together to provide energy efficiency, and is a simple, easy-to-understand system. On the scale shown in the graphic, 100 is the baseline. Anything lower than 100 becomes more efficient, while numbers above 100 are less energy efficient.

The value of buying or selling an energy-efficient home
Whether you are a home buyer or seller, there are several interesting facts about energy efficient home sales to consider.

  • From 2019: A study of HERS rated homes conducted by Freddie Mac, found that energy-efficient homes sell for more than non-energy efficient homes. On average, energy-efficient homes sold for 2.7% more than comparable non-energy efficient homes and energy-rated homes (higher rated) sold for 3-5% more than lesser-rated comparable homes. Source: Sandra Adomatis, Adomatis Appraisal Service
  • Between 2013 and 2019, there were approximately 31,000 HERS ratings in Iowa. Source: Ryan Meres, RESNET
  • As a buyer, you may be eligible for a special mortgage to cover the added cost of the rated home. Options include: HomeStyle Mortgage (Fannie Mae), GreenCHOICE Mortgages (Freddie Mac), Energy Efficient Mortgage (EEM, from FHA/HUD) and VA Energy Efficient Mortgage (VA, Veteran’s Administration).

More information

  • For more details on HERS ratings, visit the RESNET site.
  • For more details on energy efficient homes, finding a builder who performs HERS ratings or a contractor who has learned more about energy-efficient home building at our Momentum Is Building conference, contact your electric cooperative.
An energy auditor uses an infrared camera to look for areas around the window that are leaky or poorly insulated. (Source National Rural Electric Cooperative Association)