Understanding the HERS Index for Home Energy Rating

What is the HERS Index?

The HERS Index is a scoring system used to illustrate a home’s relative energy efficiency. It is based on a standard national energy calculation designed by RESNET, the Residential Energy Services Network. A HERS Index of 100 indicates that the home uses 100 percent of the energy that a comparable reference home will use. The lower a home’s HERS Index, the more energy efficient it is. The U.S. Department of Energy has determined that the HERS Index for a typical resale home is 130.

The Home Energy Rating System (HERS) is the industry standard by which a home’s energy efficiency is measured. It’s one of the widely accepted techniques for inspecting, calculating, and estimating the energy performance of a home. A HERS Rating isn’t required by most states to obtain a mortgage, but it’s still a great tool to use when comparing your home to others for sale in the area.

HERS index

Having a HERS Rating done on your home can provide you with valuable information. This includes the options available to improve the home’s energy efficiency.  Having this information is priceless as it can become a valuable guide when choosing what energy-efficient enhancements to invest in. There are quite a number of benefits that come with having a HERS Rating done on your home, many of which can help you save money and energy.

Know How Energy-Efficient Your Home Is

A HERS index score can help tell you a lot about the home you’re considering. Heating, cooling, and water heating account for more than a third of the cost of homeownership if you skip the mortgage. The HERS Index Score will tell you how well the home is performance-wise. It will cover the energy features you’re looking for in your new home.

Many homes have hidden challenges, but Home Energy Ratings (HERS) show you exactly what to look for and how to improve your home’s overall efficiency. It also provides you with valuable information about your specific home, like where to make energy improvements and how to lower your utility bills. This valuable information ultimately allows you to make educated decisions about buying, selling, and improving the comfort and value of your property.

HERS Index Score Calculations

A HERS (Home Energy Rating System) score is a measure of energy efficiency. Likewise, a HERS score of 70 is 30% more efficient than the HERS reference home of the same size. Finally, a score of 130 is 30% less efficient than the HERS reference home of the same size.

In 2009, as part of the American Recovery & Reinvestment Act, the U.S. Department of Energy determined that a typical existing home would score around 130 on the HERS index, so homes meeting this threshold are eligible to receive an energy-efficient mortgage from Fannie Mae and Freddie Mac

What Else is Included in a HERS Energy Rating?

  • HVAC system, water heating system, and thermostat.
  • All exterior walls
  • Windows doors, vents, and the ductwork
  • Floors over unconditioned spaces e.g. garages or cellars
  • Ceilings and roofs
  • Attics, foundations, and crawlspace