What Is the HERS Rating Index? Here’s All You Need to Know

What is the HERS Index?

As zero energy home builders, we talk a lot about home energy efficiency.

But how do you know if a property is energy-efficient or not?

Sure, solar panels and LED lighting reduce energy consumption. You certainly want those elements. But air leakage from low-grade windows and drywall could decrease home energy efficiency. And that’s not so easily seen.

What you need is a detailed, professional analysis of the home. This way, you can know how energy-efficient it is.

Enter the home energy rating system (HERS Index)—the industry standard for inspecting and measuring home energy efficiency. As a nationally recognized system and industry standard used by home builders, a HERS rating index details the energy performance of a home.

In this article, we’ll cover all you need to know about the HERS Index, answering questions like:

  • Why is the HERS index important to energy-efficient homes?
  • How does the HERS score work?
  • What’s the HERS rating process like?
  • Who inspects and calculates HERS scores?
  • What are the real-life implications of a good or bad HERS score?
  • How can you get a home with a great HERS score?

The HERS score explained

Established by the Residential Energy Services Network (RESNET), the HERS score is the gold standard in home energy efficiency. Launched in 2006, more than 2.64 million homes now have HERS rating.

Mostly designed for new and renovated homes, HERS Index scores range from 0 to 150. The lower the score, the better the HERS rating index is (or home energy efficiency). The chart below illustrates HERS Index score distributions:

As you can see, there are multiple reference points against which you can measure the energy efficiency of a property. Existing homes, ones that have been lived in for decades, have an average HERS score of 130. The average new home scores 100 (reference home on the chart).

As home energy efficiency improves, the HERS score gets closer to 0. A home with a HERS rating of 0 is a net zero home. Net zero homes produce as much energy as they produce.

Modern energy-efficient homes achieve HERS scores of less than 100—better than the average new home. Those with high-performance windows, solar panels, smart home automation, and other advanced features can score much lower than 100.

For example, a home with a HERS score of 70 is 30% more efficient than the average new home (which has a 100). Note each point represents 1%.

Why is a good HERS score important? 

Now that you know what HERS scores mean, you may be wondering: Why should I look at HERS scores when buying a home?

First, homeowners get a variety of lifestyle and financial benefits with greater home energy efficiency. For instance, with zero energy ready homes, you can save thousands per year on your electric bill and enjoy a healthier and more comfortable living environment. Since zero energy ready homes have superior construction, you also won’t have to deal with maintenance issues, such as a leaky roof.

Second, homes with good HERS scores make for better investments. If you plan to buy or sell soon, it could literally pay to learn about the HERS rating index system. Buy a house with a great HERS score, and you’ll save on utility bills and enjoy great resale value. Looking to sell your home? Find out where your current residence lacks efficiency, and make upgrades to increase its resale value.

“As zero energy home builders in Florida, we consult with many home appraisal experts. They will begin appraising home energy efficiency in 2023. And they tell us energy-efficient homes could have 10-15% higher resale values,” states Robert Kociecki, President of Brite Homes, a leading zero energy ready home builder in Florida.

What’s the HERS rating process like? 

As RESNET notes, certified home energy raters inspect and measure the energy efficiency of a home. These inspectors analyze a variety of home features and variables. Common areas of analysis for HERS ratings include:

  • Walls, ceilings, and roofs: How’s the insulation? Is there any air leakage?
  • Windows, doors, vents, and ductwork: Air-tight windows conserve energy better.
Beautiful inside photo of a Brite home.

Make your home more energy-efficient with high-performance windows and doors

  • Attics, foundations, and crawl-spaces: These are common areas where warm or cool air escapes, causing more energy usage. Insulation in attics and other overlooked areas where air escapes can boost home efficiency.
  • Heating, ventilation, and air-conditioning (HVAC) systems and the thermostat: HVAC systems with a higher SEER rating will save more energy. SEER stands for seasonal energy efficiency ratio. A smart, programmable thermostat makes a home more efficient too. Considering heating and air accounts for roughly 55% of a home’s energy expenses, optimizing energy efficiency here can save lots of money.

Energy-saving solutions: LED lighting, solar panels, and ENERGY STAR-certified appliances can make your home more energy-efficient.

Beautiful outside photo of a Brite home.

One of Brite’s zero energy ready homes! Like the solar panels?

Once HERS rating inspectors collect all the data, they calculate the HERS score of a home. The rating can give home buyers and sellers lots of information about where energy is being wasted, and how a home’s design can be improved for better performance.

If you want to find out the score of a certain home, you can do a home search on RESNET’s site. RESNET also has a HERS scoring guide so you can learn more about the HERS rating process. It’s an interactive tool that teaches you how to assess a home’s energy efficiency.

Live in a home with a great HERS score

Now you understand the real-life implications of the HERS Index. From lower energy bills to higher home comfort, living in an energy-efficient home makes all the difference.

When shopping for a new home, you can hire a certified RESNET rater to assess a home’s energy efficiency. This investment will pay off in the long run. You’ll know what house has the best performance and therefore provide the best ROI.

You can also go directly to an energy-smart builder. At Brite Homes, we’re leading the way in building zero energy ready homes in Florida and beyond. Our homes achieve great HERS scores and can deliver the lifestyle and savings you seek.

What to start living more energy-efficient? Click to find out how!