Have you every heard someone talking about the energy efficiency of a home and say something like, "What's the HERS Score…" or "The HERS Score is…."? If you haven't, you will. As we become more and more energy conscious, terms likes this will become common place. Let's take a few minutes to give a brief overview of what a HERS Score is and how it is used.

RESNET and HERS Score
HERS stands for Home Energy Rating System and was established by the Residential Energy Services Network or RESNET. It was created to be able to objectively score a home's energy consumption in comparison to the International Energy Code Council standard. As of the time of this writing, the 2006 IECC is the base line from which HERS Scores are generated. The IECC establishs the minimum energy standard to which a home should be built. For more on the ICC, click on the embedded link above. Now that you know the origins of HERS and who created it, what does it mean for your home and what is a good HERS Score?

WHAT DOES IT MEAN
Let's say your are in the market to buy a new or used home. You find two, one new and one 5 years old. You like both, but are having a hard time deciding which one to go with. This can be a tough choice. Of all the variables that go into your decision, one that should be a part of the equation is "How much energy does this house consume to heat and/or cool." The past utility bills can help but that doesn't tell you the life style variables that may be a part of ownership. Second, the new house doesn't have a record of utility bills for comparison. This is where a HERS Score will help as it is an objective way to compare the two houses energy consumption and help in the decision making.

You ask the builder of the new house and homeowners of the existing house to give you the HERS Score for their houses. They do and the new house has a HERS Score of 68 and the 5 year old house has a HERS Score of 130. OK, now what?

HOW TO UNDERSTAND THE HERS SCORE
A house that is built to the 2006 IECC and meets the minimum requirements will have a HERS Score of 100. This would be considered a "Base Line" house. Stated another way, it uses 100% of the energy allowed per the Energy Code. On the other hand, a house that scores higher than 100, say 115, consumes 15% MORE energy than is allowed per the Energy Code. And vica versa, a house that scores 85 consumes 15% LESS energy than is allowed per the Energy Code. In order to qualify as an "Energy Star" home the HERS Score must be at least an 85. The lower the HERS Score the more energy efficient the house is and the less your monthly utility bill is.

Now back to our example, the 5 year house consumes 62% MORE energy than the new house and 30% MORE energy than is allowed by the 2006 Energy Code. This may be just the information you need in making your final decision. In this example, if the average monthly utility bill of the 5 year old house is $300.00 the new house would cost you a monthly average of $114.00 or about $186.00 per month and $2232.00 less per year to operate. If the cost to make the "Energy Star" improvements is $5000.00, this would add approx. $30.00 per month to your mortgage. The real question is "Would you spend $30.00 per month to save $186.00 each and every month?" And also consider that as utility costs increase, which utility bill would you want to double? $114.00 or $300.00

 

 

The article above is used with permission from Jon Ruch, Builder