In 2009, Massachusetts became the first state to adopt an above-code appendix to the base building energy code known as the Stretch Code. The Stretch Code is an alternative, more stringent, energy code for Massachusetts towns to adopt. It emphasizes energy performance and is designed to result in cost-effective construction that is more energy efficient than the mandatory state-wide base building energy code. It is updated periodically in accordance with the base energy code in Massachusetts, which is updated every 3 years.

 

In order to meet the requirements of the Stretch Code, builders must hire a certified Home Energy Rating System (HERS) Rater, such as A9 Green, to determine if the home's energy-efficiency meet the standards of the code. New residential construction in a Stretch Code town will need to follow the Performance Path of the Base code and achieve a HERS rating of 55.

 

As of July 22, 2020, the Stretch Code has been adopted by 283 out of 351 municipalities in Massachusetts.