In this column, staff at the Center for EcoTechnology offer advice on easy ways for people — and businesses — to introduce green changes in their daily lives.
Q: I keep hearing about HERS ratings and that I should get one for my home. What's a HERS rating?
A: HERS stands for Home Energy Rating System and it is the nationally recognized, uniform and unbiased standard for measuring a new home's energy efficiency.
Developed by the Residential Energy Services Network (RESNET), HERS ratings are measured against a HERS Index that runs from 0 to 150, with higher scores being less efficient and lower scores being more efficient (much like golf, you'd prefer to have the lower score).
It involves analysis of how effective a home's insulation is, whether there are any air leaks (and how severe they might be) in a building's envelope, the amount of leakage in heating ducts, the safety of your heating system and home design, such as floors over garages or cellars that are not conditioned, windows and doors and thermostats.
The testing typically involves a blower door test, appliance efficiency, duct leakage testing, window RV value testing and use of infrared cameras.
Q; Okay, so why does it matter how efficient my home is?
A: Think of a HERS rating as a "miles per gallon" measure for your home. If you put your home on the market, it's helpful to have an easy way to show a potential buyer how efficient the home is. It is a great potential selling point to be able to say "this house is 50 percent more efficient than a standard new home."
HERS was developed according to federal guidelines to assist the mortgage industry, and borrowers can now use energy-efficiency mortgages (EEMs), which take into account a home's energy savings, allowing a larger borrowing amount. EEMs also allow borrowers to use their mortgage to finance energy improvements, paying for them over the course of the mortgage instead of up front, which makes buying an energy-efficient home (or one that you will be making energy-efficient) much more affordable.
In addition, a HERS rating service will also produce a report detailing some cost-effective improvements you could make, as well as help you qualify for any financial incentives that may be available, particularly for new construction.
Speaking of new construction ... did you know that over 160 Massachusetts towns, including several in Berkshire County, now require a HERS rating for any new construction, and some renovations and additions, as part of their adoption of stretch energy code? You can find a full list of stretch code municipalities at www.mass.gov/eea/docs/doer/green-communities/grant-program/stretch-code-towns-adoption-by-community-map-and-list.pdf.
For more on HERS, check out www.resnet.us/hers-index or call CET at 413-586-7350, ext. 242.
Look for this column in The Eagle every two weeks. Send Go Green questions to GoGreen@cetonline.org.