HERS Index Rating – Miles Per Gallon For A Home

HERS Index RatingThe energy crisis of 1973 had a dramatic effect on the auto industry.  Congress enacted the Energy Conservation and Policy Act of 1975 to regulate the fuel economy of passenger cars and light trucks.  The government then enacted the Energy Tax Act of 1978 to establish a gas guzzler tax on the sale of new vehicles whose fuel efficiency failed to meet certain statutory levels.  Now you can’t buy a car without looking at the huge MPG sticker located on the window at the dealership.  Consumers are very conscious about the fuel efficiency of their cars and requirements are becoming more and more stringent year after year.

What does this have to do with homes?  Well, you are starting to see the same trend with homes these days.  As utility costs continue to rise, consumers are paying more attention to ways to save energy and money.  Whether its a new or used home, buyers are getting much more savvy prior to purchasing.  The days of just listing possible energy efficient features of the home are falling by the way side.  Buyers are starting to realize that just because the home has Energy Star appliances doesn’t mean it will perform at a high level.  Builders that are constructing energy efficient homes need to find a way to market that fact, the same way car manufacturers market the fuel efficiency of their cars compared to the competition.

The HERS Index Rating is like the MPG for homes.  RESNET has developed detailed procedures for analyzing a home.  Data from building plans and specs is collected by a certified building science expert (HERS Rater) and modeled into advanced software to determine the projected or actual performance of a specific home.  Using the combination of building science and data collection from facts and advanced testing is what gives this rating credibility.  There is no guess work and the HERS Index rating is not subjective.

What is the HERS Index Rating?

The certified HERS Rater will model every component of the home into advanced software (components that effect the efficiency of the home.  For example, insulation, windows, HVAC equipment, etc…).  The rater will also inspect the home during construction to make sure the building specs align with what is actually being installed.  Once the home is complete the Rater will then do advanced testing on the home to determine the air infiltration level (Blower Door Test).  After final inspection is done the Rater will complete all the reports to generate a HERS Index.

What is the HERS Index number mean?

The HERS Index comes from a numbered scale.  On this scale there are two set points.  These set points are 0 and 100.  0 is a Zero Energy Home (Net Zero Home) which is a home that produces as much energy as it consumes.  100 is a home built to the IECC (International Energy Conservation Code).  Each point equals 1% change in energy consumption.  For example, lets say a home gets a HERS Index of 80.  This means the home will use 80% more energy than a Zero Energy Home and 20% less energy than a home built to code.  Most homes that are built here in West Michigan will fall between a 60 and 80 HERS Index.  The lower the index number the better.

Can this be done on existing homes?

Yes, an existing home can get a HERS Index Rating.  Some estimating will have to be done since the home can’t be inspected during construction but the rating should still be very accurate.  The HERS Index Rating is more widely used in new home construction but many energy auditing companies are utilizing it for existing homes as well.

Who does this benefit?

If you are a builder not using the HERS Index Rating, consider adding it to your product.  Many builders are utilizing this rating and they are ahead of the curve.  Not only does this give you an advantage compared to your competitor, it can be used to pull your initial building permits as well as obtain your certificate of occupancy when the home is finished.  It is a great tool to market to your potential customers.

If you are a buyer looking to build a home.  Make sure your builder is getting a HERS Index Rating on your home.  Finding a builder who is currently using this service means they are already committed to building an energy efficient home.  The same way you trust your builder to bring in an electrical expert to run your wiring, you should expect them to be bringing in a building science expert to make sure the home will perform safe and efficient.

GreenEdge of Michigan is a certified HERS Rater.  We also offer many other energy auditing services to meet your needs.

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