Energy codes can be confusing.

Find out which one applies to your project.

Energy Codes in Massachusetts

We provide support services to help residential home builders, architects and developers navigate energy code details and meet compliance. Whether you need to meet IECC or Stretch Code requirements, we can help! Call or email us today with any questions you may have about your project.




Massachusetts has a base energy code that all new buildings in the state must follow. It is based on the most current version of the International Energy Conservation Code (IECC) which establishes a baseline for energy efficiency by setting performance standards for the building envelope. Provided the mandatory requirements are met, the rest of the code can be met by either following the prescriptive or performance path.

Performance Path Compliance:

The performance path requires energy modeling to demonstrate that the building as a whole uses equal or less energy than a home built to the prescriptive path. Even though the performance path is slightly more involved, it allows flexibility to trade off many of the high-cost assemblies required in the prescriptive path resulting in substantial savings.

To comply with the Performance Path, you will need either a simulated energy performance analysis or an Energy Rating Index (ERI) analysis. The ERI path, specifically a certified RESNET HERS Rating, is the performance path most often used to achieve energy code compliance in base energy code communities.

We highly recommend following the Performance Path utilizing a HERS Rating.  A HERS Rating is the most realistic compliance option that offers documented energy savings while giving you more flexibility and “trade offs”.

Prescriptive Path Compliance:

The prescriptive path requires that each component is built to a specified R-value or U-value found in the prescriptive table. While the prescriptive path is a traditional approach and can be achieved without the aid of any software, it does not have much flexibility and therefore does not allow trade-offs to lower assembly cost.

To comply with the Prescriptive Path, you will need:

  • A REScheck certificate
  • Performance Testing – blower door test, duct testing, and ventilation testing
  • To meet insulation specifications
  • To meet window performance specifications

**This path is not eligible for Mass Save® incentives**





Massachusetts became the first state to adopt an above-code appendix to the IECC base energy code- the “Stretch Code”. The Stretch Code, which emphasizes energy performance, as opposed to prescriptive requirements, is designed to result in cost-effective construction that is more energy efficient than that built to the IECC base code.

Stretch Code Compliance:

Most Massachusetts cities and towns have adopted the Stretch Code – take a look at the map below to see if the town/city you are building in has adopted this new energy code. New homes being built in these towns/cities require a HERS Rating and must get a HERS score of 55 or less.  Many renovations in these towns also require a HERS Rating and must get a HERS score of 65 or less.

For more information about about the Stretch Code, check out out our “Stretch Code Q&A” article.


Stretch Energy Code Map



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