What Does A Low HERS Rating Actually Mean?

When it comes to buying, selling, or developing houses, you’ve likely heard of a HERS Index or HERS score. At this point, you’re probably asking what this score means, and why it’s important. The Home Energy Rating System (HERS) Index is a national industry standard by which every home’s energy efficiency is measured. The lower the score, the better for you and the environment. 

Let’s explore what this means and why it’s beneficial to know about it. 

What Is The HERS Index?

The HERS Index was launched in 2006 to calculate a home’s overall energy efficiency. HERS scores are generally designed for new homes or just after a renovation. In order to meet all efficiency standards, builders will make use of the HERS index. 

To get a HERS score, a qualified RESNET rater will need to inspect your house or development with all the necessary equipment. This process can be quite lengthy and is definitely an investment. Despite the cost, energy improvements that lead to a good HERS score will save any homeowner more money in the long run. For homebuilders and developers, it increases the sale value – resulting in increased profits.

The rater will rate the home on energy efficiency and consumption. A lower score means that the home is more energy-efficient than a home with a higher HERS score. A score of 0 (net) indicates that the home creates as much energy as it consumes through exemplary construction and renewable resources.

Variables Included In An Energy Rating

A variable is a quantifiable parameter that significantly impacts energy performance and also changes regularly. Examples of this include production rate, product temperature, climatic indicators, as well as pressure and flow.

Some things the energy rater may look for include but are not limited to:

  • Ceiling, roofs, and wall insulation
  • The air infiltration rate
  • Any air leaks in the house or building envelope
  • All exterior walls
  • Floors above unconditioned spaces, such as cellars or your garage
  • Heating, ventilation, and air conditioning (HVAC) distribution duct leaks
  • Home water heating systems
  • Vents, windows, doors, and all ductwork
  • Foundations, attics, and other crawl spaces
  • Thermostats

What Does It Mean To Have A Low HERS Rating?

In short, a lower HERS score is important as it means that your home is incredibly energy efficient. This leads to lower electricity bills, as well as enhanced comfort, and increased resale value. 

When purchasing a new home, we recommend you look for a house with a lower HERS score, as research shows that these homes are proven to be money-savers in the long run.

Homes with lower HERS scores will also benefit from the following:

  • Higher appraised value
  • Overall lower utility costs
  • Increased comfort and health benefits due to reduced temperature fluctuations 
  • Potential decreased mortgage default risks 

How Are HERS Index Scores Calculated?

As mentioned above, the lowers the HERS score, the better the home’s overall energy performance. The HERS baseline score is 100 (newly built home to code).  Below, is a general guide to HERS scores and what they mean. 

150 HERS Score: This house will likely use 50% more energy than a new home built according to the standard energy code. This is usually applicable to older homes.

100 HERS Score: A new house constructed according to the current building code standards for home energy efficiency.

50 HERS Score: A house that uses 50% less energy than new houses built to code.

0 HERS Score: A house that uses no energy. This house will generally use some form of wind or solar energy generation.

-10 HERS Score: This house likely generates more clean energy than it takes from the grid. Negative HERS scores indicate that the home puts energy back into the grid. These are ‘Positive Energy Homes’.

With these scores in mind, our goal at EcoSmart Solution is to build homes of the future. Our Zero Energy Capable (ZEC) homes use geothermal heating and cooling systems with minimal carbon emissions. We make sure to either meet or exceed energy codes to create more sustainable homes with a target HERS rating of 25 or less, meaning that our homes could potentially use over 50% less energy than other houses.  

Benefits of a Good HERS Index Score

Having an energy-efficient home is not just good for the environment, it is also more cost-effective and comfortable for homeowners. For example, a home that conserves heat will be significantly easier to live in during winter. For this reason, a HERS index score will help you understand what aspects of your home you need to improve for better energy conservation. 

Most people assume a HERS score is designed to assess new homes. This is not the case as you can easily get a score for a lived-in home to assess how well it functions. 

This assessment will help you to better understand the state of your home, allowing you to discover any energy leakages you can improve – especially in places you never thought to check! Not to mention, installing more energy-efficient systems will save you money on your electricity bills in the long run.

If you want to sell your home or are in the business of home-building, a low HERS score is incredibly beneficial for a home’s sale value. Homes with lower HERS scores and good energy efficiency can be priced higher than other homes that may be less energy-efficient.

When purchasing a new home, we recommend paying a little bit more for a house that includes a good HERS score. While it may seem costly upfront, the energy savings in the long-term will certainly make up for it. For example, our EcoSmart Solution ZEC homes aim for a HERS rating of 25 – meaning an average saving of $1250 per year


Whether you want to buy a new house or build homes with higher sale values, the HERS test can help you evaluate overall energy performance. The lower the HERS score, the higher the sale or resale value. 

Most importantly, a HERS test will help you better understand how your property can be more energy efficient. This can not only help you save money on your bills or sell at a higher profit but it’s better for the environment.

At EcoSmart Solution, we are proud to offer Zero Energy Capable homes as a more sustainable living solution. With our HERS-certified homes, we ensure reduced energy usage and lower utility bills, while contributing to a cleaner environment and world for all.

Interested in learning more? Get in touch.