Energy codes can be confusing.

Find out which one applies to your project.

The HERS Index

HERS Ratings

With the Massachusetts energy codes getting stricter, it is becoming harder to achieve the code mandated HERS Score. Our team of RESNET certified raters has 20+ years of hands-on construction experience and with over 6,500 HERS ratings under our belt, we know what it takes to help you get the best HERS score possible for your project. We work with you to identify any weak links early on during the design stage and provide support throughout the entire construction process.




HERS stands for Home Energy Rating System, a HERS Rating is the industry standard for measuring the energy efficiency of a home.  It is a holistic view of the energy usage of the home; incorporating performance testing, building materials, HVAC equipment, appliances, and lighting. A HERS Rating is the most common method to show compliance with local energy codes, and in Stretch Code communities a HERS Rating is mandatory.  A smooth path to energy code compliance starts with a HERS rating and a great HERS Rater.



We perform a suite of tests on the systems in your home to measure their efficiency.  These tests include a blower door test, a duct test (if ductwork is present), and a ventilation test.  All of these tests are non-invasive and will not disrupt or impair the home.  These test results are input in to a HERS Rating software to help calculate the HERS Score of the home.

Check out our article – “Performance Testing”



A HERS Rating looks at an array of building materials used in the home and calculates the impact each component will have on the HERS Score.  Insulation types, depth, and quality of installation are all documented to calculate the R-Value of the walls, floors, and ceilings of the home.  Windows have performance ratings to show the insulation factor, U-Value, and how much solar energy radiates through the glass, solar heat gain coefficient (SHGC).  Additional factors including the framing factor of walls, or radiant barriers on roofs are also documented and entered into the HERS Rating software.



What utilities are available on your site?  This questions drives the type of heating and cooling system that you select for your project. We will document the type, size, fuel, and efficiency of your heating and cooling system.  Domestic hot water (DHW) systems are also recorded to determine the efficiency, fuel, and type of those systems.  Distribution systems for the DHW are also examined for features including pipe insulation and total system length.  Ventilation systems are inspected to ensure compliance with applicable building codes.



The type and efficiency of your appliance package can affect your HERS Score.  There are certain appliances which are known as minimum rated features, items that we will have to put into the HERS Rating.  These items are the refrigerator, dishwasher, range, washer, and dryer. You don’t have to have all of these items, a default setting can be used but most appliances sold today are more efficient than the default.  We will also look whether your lighting is high efficiency LED lighting, compact fluorescent, or incandescent.




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