top of page
  • Writer's pictureColleen

HERS® Index

Since getting my Green Designation I want to talk about some of the things I've learned and share the knowledge with you all. One of the things we learned about was the HERS® index, so lets get into what it is and why its important:

What's a HERS® rating?

HERS® stands for Home Energy Rating System. The HERS® index was created by RESNET® and it has become an industry standard for rating home energy efficiency. A HERS® home energy rating is an in-depth analysis of a home’s energy performance that identifies how efficiently it is operating. Each HERS® rated home receives a HERS® Score based on its performance.

How do I read the rating?

Each 1-point decrease on the index is designed to correspond to a 1% reduction in energy consumption, compared to the baseline reference home which has a score of 100.

Example 1: A home scoring 70 on the HERS® Index is 30% more energy efficient than the reference home.

Example 2: According to RESNET®, the U.S. Department of Energy has determined a typical resale home has a HERS® rating of 130. That's 30% less energy efficient than the reference home.

Basically it's like golf, where the lower you score the better off you are doing.

Where can I find a home's HERS® rating?

Each new home built will receive a Confirmed Rating—not just an estimate—provided by a Certified HERS® Rater. They'll perform on-site visual observations and tests for rated features following RESNET®/ANSI®/ICC® standards. So if your home is new you probably already have it. If you are buying resale, then talk to your Green Designated REALTOR or you can find where to order the test here:

Benefits of Having a HERS test done:

Lower Home Ownership Costs there is a $235,000,000 annual energy savings for HERS® rated homes in the US in 2018. An energy-efficient home can help you save anywhere from 5% to 30% on energy bills according to the DOE.

Breathe Easier With Healthier Indoor Air Fresh air ventilation that replaces stale indoor air with cleaner, outdoor air.

Better Home Comfort That You Can Feel No cold spots in rooms in the winter or stiflingly hot rooms during the summer. HERS® rated homes offer better energy performance and are better built and better insulated, making them warmer in winter and cooler in summer.

Less Worry Energy performance and build quality that has been tested and certified by a HERS® rater. The confidence of knowing your home has been inspected and tested to meet national energy standards by a trained, certified and independent HERS® rater.

Higher Resale Values Energy efficient homes sold 89 days faster than traditional homes in 2018 as compared to 2017. Energy efficient HERS® rated homes sell for a premium anywhere from 3.5% to upwards of 9% and more compared to standard homes.

Better for the Environment The 236,000 homes that were HERS® rated in the US annually reduces over 1 million tons of carbon production every year. When you buy a HERS® rated home, you’re helping reduce your home’s pollution and carbon emissions, and protect the environment.

Help Boost the Economy Energy efficiency sector added 67,000 jobs in the US in 2017. HERS® rated homes help stimulate the economy through lowering energy costs for families, industry and businesses, and by creating jobs in the energy efficiency sector.

What can lower a home’s HERS® rating?

Efficient HVAC system designed to perform efficiently for each plan. More efficient HVAC equipment—such as up to 16 SEER air conditioning and mid- or high-efficiency furnaces—can also help lower the HERS® rating. Variable-speed ECM furnaces can also use less energy.

Mechanically controlled ventilation helps promote better indoor air quality by providing a controlled amount of outdoor air. Dedicated ventilators can help lower the HERS® rating.

Advanced framing methods help reduce lumber used, increase effective insulation and reduce waste.

Effective insulation solutions help balance temperatures throughout the house for increased comfort. Quality installed insulation can help improve energy efficiency and lower the HERS® rating.

Radiant barriers reduce summer heat gain and lower cooling costs by reflecting radiant solar heat that would otherwise be absorbed by the home.

Interior air sealing helps separate a home's living space from the outdoors, reducing infiltration, drafts, dust and pollen while cutting down on loss of conditioned air. Reducing air leakage can help lower the HERS® rating.

Energy-efficient windows can affect a home's HERS® rating in a variety of ways. Low-emissivity coatings reflect infrared light to help keep heat inside in winter and outside in summer. A window's U-Factor measures how well it can keep heat from escaping a room, while its Solar Heat Gain Coefficient (SHGC) expresses how well it can resist unwanted heat gain. Lower numbers mean less energy spent in heating and cooling.

Tankless water heaters provide hot water on demand, typically using less energy without sacrificing comfort and convenience. High-efficiency tankless water heaters can help reduce the HERS® rating.

High-efficiency lighting, such as LED and CFL lights, provide comparable light while using less energy, which can contribute to a lower HERS® score.

Programmable thermostats allow the homeowner to reduce home heating and cooling requirements during times that the home is not occupied and at night.

Energy-efficient appliances use less energy to perform the same function as standard appliances, leading to savings over the life of the device. Many appliances offered or available such as dishwashers, refrigerators, washers and dryers are also ENERGY STAR® qualified.

Solar power systems can reduce a home’s reliance on non-renewable energy sources and lower its HERS® rating by 20 points or more (based on a system size of 4 kW).

Recent Posts

See All


bottom of page