There are a few basic building blocks you need to grasp to get a solid understanding of Energy Efficiency as it relates to homes. H.E.R.S. is one of the critical ones. A HERS rating provides an unbiased measurement of how efficiently a home uses energy. The HERS rating quantifies the energy performance of a home based on a set standard, and therefore provides an easy way to compare the energy efficiency of different homes.
The measurement or HERS Score is calculated by a certified HERS rater using an energy efficiency software package to perform an energy analysis of the home’s design. To be certified, a HERS rater must successfully complete RESNET (Residential Energy Services Network) training and abide by RESNET requirements, they do not report to any builder or energy certification program.
A HERS rating of 100 would be the rating for a home built to the current code, but not exceeding code. A HERS rating of 250 would use 2.5 times as much energy as one with a rating of 100. A HERS rating of 50 would use only 50% of the energy of one with a rating of 100.
As more people request this information from Builders and Sellers, the HERS rating will become more important in a home sale. After homeowners discovered a mortgage payment may be affordable, but high utility bills can take the same home and put it beyond their means.
If a HERS rating or Green Building/Retrofit certification is not available for a home you are interested in purchasing make certain you ask for copies of the utility bills before making your offer. This will give you a good estimate what the home will cost you every month.