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What is a HERS Rating for Homes: The Ultimate Guide

July 27, 2021

What is a HERS Rating for Homes: The Ultimate Guide

HERS Score for Houses Explained

More new homes being built in Illinois now include a HERS Rating. The Home Energy Rating System (HERS) is a method that is used by builders like 5th Avenue Construction, to determine the overall energy use of a home. The HERS Rating was developed by the Residential Energy Services Network (RESNET), which is a nationally recognized standard for measuring the energy efficiency of a home. Custom home builders use the HERS score to rate their homes to make sure that the house that they built meets the energy code requirements of the municipality the home is located in.

High or Low: What Does a HERS Score Say About a Home?

The HERS rating measures the energy efficiency of a home and will be able to tell you how efficiently the home is operating and where you can make improvements for greater energy savings. When in the process of selling a home, a low HERS Index Score can bump up its resale price. On the opposite end, if you are looking to buy a home it can help you estimate the costs of future energy bills and will give you an idea of the type of upgrades you need to do to a home to increase its energy efficiency.

People are looking to purchase homes that are energy efficient as it reduces their monthly expenses, minimizes their carbon footprint, and helps the home’s value if they need to sell down the road. The HERS Score of a home is even now added to MLS listings so that buyers can see a home’s energy efficiency when they look at a listing.


How Does the HERS Index Work?

To calculate the HERS Score of a home, the rater will perform a full energy rating by analyzing information on the home’s energy aspects using a sophisticated software modeling tool. The results of the data will be compared to a “reference home”, which is the same size and shape as the home being rated, and from this comparison is where the HERS Score is calculated. The lower the score the home receives, the better and more comfortable and energy efficient that home is.

As an example, a home with a HERS Index Score of 70 is 30% more efficient than a standard newly built home, whereas a home with a score of 130 is 30% less efficient than a new standard home. A home can even receive a HERS score of zero which would mean that the home consumes net-zero energy and is probably built with renewable energy resources like photovoltaic (PV) solar panels.

Part of all HERS ratings are field testing and verification, including the following: insulation levels verification, heating, cooling, water heating specifications, window specifications, appliances and lighting specifications and a blower door air leakage test.


The Steps to Completing a HERS Rating


A HERS Rating requires a multi-step process, there are steps before, during, and after, but there are 3 main stages are as follows:

To conduct a HERS Rating, there are multiple steps that are taken to find the correct rating for the home that is being tested. There are three main stages to conduct a HERS Rating.

Projected HERS Rating: 

A projected HERS rating is usually completed before ground is broken for a new construction home. The certified HERS rater will meet with the builder to verify that the construction is following the plans for the project and will use these plans to estimate what the HERS rating will be if the build plans for the home are followed exactly.

Mid-Construction Verifications: 

During the construction of the new home, the HERS rater will check in with the builder to verify that the plans are being followed and the home is on track to meet the projected rating. Mid-construction verifications are necessary because after construction is complete some of the components of the home can’t be seen or altered. An example of these items would be duct leakage ratings and insulation levels.

Final HERS: 

To complete the HERS Rating Process, the final HERS inspection is conducted in the last stages of the construction of the home. The rater will visit the build site and verify that was planned for the home was installed, complete the final tests like the blower door test, and will collect all the final data on the home for the HERS rating.


What Does the HERS Index Look Like?


The HERS rating process is solidly defined for the construction community as a solution to meet specific building codes for the communities that they build in. For consumers, the HERS score is the rating that can be used to compare properties when on the hunt for a new home.

As a house-hunter, the HERS score can be used as a reference for the energy efficiency of the home. The lower the score, the more efficient the home is. The HERS Index (pictured above) uses a scale where a score of 100 is a standard new home score, and a HERS score of 0 indicates a home that uses zero energy (ex: a home that has solar panels and creates the amount of energy the home uses). 

Useful for when purchasing a home or building a new one, the HERS Score gives insight into the future energy consumption, energy bills, and overall comfort will be for that home.


Examples of HERS Scores & Their Meaning:

A HERS score of 130 is 30% less efficient than a standard new construction home. With this score, many existing homes that are older than 20 years with minimal upgrades would score within this range. 

A HERS score of 70 is 30% more efficient than a standard new construction home. Getting this score is a huge improvement and is not difficult to reach for an existing home that previously had a higher rating. Newer homes or older homes with improved insulation levels, homes updated with higher efficiency heating and cooling systems, and high efficiency lighting will score within this range. 

A HERS score of 50 is 50% more efficient than a standard new construction home. Homes in this range have more effort put in towards “green building”. This type of home will be built with energy efficiency as an important component. Green homes will have above average insulation levels, high efficiency HVAC systems, higher quality windows, and more efficient water heating.

A HERS score of 0 is 100% more efficient than a standard new construction home and is a net-zero energy home. A net-zero energy home is a house that puts energy conservation first and do so by being air-tight, very well-insulated, and energy efficient that they produce as much renewable energy as it consumes over the course of a year. 

This leaves the occupants with a net-zero energy bill and a carbon-free home. Often these types of homes have PV solar panels installed to create the energy that the home consumes.


What Home Updates Affect a HERS Score?

Using specially designed HERS software, a certified HERS rater will model a home from top to bottom to estimate the HERS score of a home. Each energy design change will affect the final HERS score of a home in order to improve it. Builders will take this into account when designing a new construction home or when they are making updates to an older home in order to make it more energy efficient.


Here are some key factors that will affect the final HERS rating of a home:

The square footage and insulation levels of the thermal envelope of a home. The thermal envelope is any structure in a house that separates the air inside the house from the air that is outside. This would be the insulation, floors, windows, outer walls, ceilings, and exterior doors.

The windows of the house, this includes the window area, its orientation, shading, and the quality of the insulation the window has.

The heating and cooling appliances and the water heating equipment.

The lighting used and the standard appliances that use energy in the house. This includes all kitchen appliances, along with the washer and dryer.

The air leakage rate of the house, which is found by conducting a blower door test on a finished house. High air leakage equals more energy being needed to keep the house heated or cooled properly.

Updating or changing any of the items listed above can vastly improve a home’s HERS score. With the data, the HERS rater can help balance the inputs and help a homeowner or builder find different ways to reach the HERS score goal of any property. This information can also help builders like 5th Ave Construction in their projects by knowing if they should make trade-offs for a particular home.

A “trade-off” is where a builder will add more than one energy efficient appliance or feature to offset the lack of another. This is not a bypass for energy codes, rather it helps notify the builder where there is a design issue so that they can make the improvement in order to achieve energy compliance in an area of the home where it may be more difficult to achieve.


5th Ave Construction Builds HERS Rated Homes

5th Avenue Construction designs and builds homes that keep energy efficiency in mind for the betterment of our customers and the environment. We've partnered with Home Comfort Consultants, a trusted third party energy rater with a HERS Certification to make sure that our custom built homes are energy efficient and score well on the HERS Rating Scale. Check out the quick video below of Steve Osborn of Home Comfort Consultants as he explains what a HERS Score is and what it means for our homes.

Our custom built homes feature energy efficient appliances along with the following: programmable digital thermostat, a 13 Seer Air Conditioning, Dual Zone HVAC System, Rudd RGRS 90% Upflow Gas Furnace, a high efficiency 50-gallon hot water heater, Tyvek House Wrap Moisture Barrier, and energy efficient exterior entry doors and windows. 

Along with these features, most importantly our homes feature Nu-Wool Cellulose Insulation for a tighter building envelope for superior energy savings and sound control.



Are You Ready to Build Your Energy Efficient Custom Home?

It’s time to contact a custom home builder that you trust. 5th Avenue Construction crafts homes with integrity and professionalism, as it is our mission to build the home of your dreams and have it be everything that you have always wanted. 

Our experienced design team will be with you every step of the way and will offer their expertise on your selections choices and on the most effective way to use your budget. 


Have more questions or want a consultation?

Contact our VP of Sales for a free consultation and find out how we can craft the home of your dreams. Call us at (331) 255-7500 or email us at info@5thavemgmt.com.