The Ultimate HERS Rating Guide Part 1: What Is A HERS Rating?

Date Published: December 8, 2015

The HERS Rating Index, developed by RESNET:

More new homes are being built with a HERS Rating, particularly in Colorado.  The Home Energy Rating System (HERS) is a method used by architects, builders, and energy raters, to determine the overall energy use of a home.

RESNET, the Residential Energy Services Network, developed the HERS Index standard, which is a nationally recognized standard for measuring the energy efficiency of a home.  Many Colorado home builders use the HERS score to rate their homes, and several area municipalities use the HERS score to validate whether a home meets their energy codes, including the City and County of Boulder.

What does a HERS Rating say about a home?

The HERS rating measures a home’s energy efficiency and can tell you how efficiently it is operating and where you can make modifications for greater energy savings.  When you are selling a home, a low HERS Index Score can command a higher resale price.  And when buying a home you can anticipate the costs of energy bills and efficiency upgrades.

The video included in this post was published by RESNET to give an overview of the HERS Rating process. In the video, they mention a very important point about the HERS score. If a home has a lower HERS score, meaning it is more energy efficient, the price of the home should increase in value.

People want to buy more energy efficient homes. It reduces their monthly expenses, reduces their carbon footprint, and helps when they need to sell later. This shift has been reflected in many facets of the home buying industry. Just recently, the HERS score was added to many of the MLS providers so buyers can see a home’s efficiency when looking at the listing.

So what does a HERS Rating say about a home? A lot really. And because of that, it is becoming more and more popular among builders, building departments, and the general public.

Are you a Colorado Builder in need of a HERS Rating for your next building project? Learn more about our certified HERS Rating Services here. 

How does the HERS Index work?

To calculate the HERS Score, the rater performs a full energy rating on the home by analyzing information on the home’s energy aspects using a sophisticated software modeling tool. The results of the data analysis are compared against a “reference home” which is the same size and shape as the actual home, and from which a resulting HERS score is created.  The lower the score, the better. A lower score means the home is more comfortable and energy-efficient.

For example, a home with a HERS Index score of 70 is 30% more efficient than a standard new home, while a home with a score of 130 is 30% less efficient than a standard new home.  A HERS Index score of Zero would mean the home consumes net-zero energy and likely has renewable energy installed on the home, such as Photovoltaic (PV) Solar panels.

Field testing and verification is performed on all HERS ratings, including verification of insulation levels, window specifications, heating, cooling, water heating specifications, appliance and lighting specifications, in addition to performing blower door air leakage testing.

We will go into even deeper detail of the HERS score index in part 2.