Building Energy Code

Summary of State Building Energy Codes including the Stretch Code

Table of Contents

Energy Efficiency Provisions of the State Building Code (780 CMR)

As part of the Green Communities Act of 2008, Massachusetts is required to update its building code every three years to be consistent with the most recent version of the International Energy Conservation Code (IECC).

Accordingly, Massachusetts has adopted the IECC2018 with MA amendments, effective Feb 7th 2020, and running concurrently with the IECC2015 amended code until November 7th 2020. From November 8th 2020 onwards, the IECC2018 with MA amendments is the minimum energy code for new building permits in Massachusetts.

The IECC2018 is available from the International Code Council website: 
Note: Commercial buildings may also follow ASHRAE standard 90.1-2016 and a joint IECC2018/ASHRAE-90.1-2016 code book is available.

The Commercial building energy chapter (which also covers large multi-family) is Chapter 13: Energy Efficiency Amendments (as of 2/7/20)

The Residential low-rise building energy chapter is Residential Chapter 11: Energy Efficiency Amendments (as of 2/7/20)

The Stretch energy code is summarized in this PDF: 780 CMR 115 Appendix AA but references chapter 13 and Residential chapter 11 depending on the building size and type. Large commercial buildings covered by the Stretch code remain based on the 2013 ASHRAE standard 90.1-appendix G, not the newer and heavily revised 2016 version of ASHRAE appendix G.

Stretch Code Summary

In 2009, Massachusetts became the first state to adopt an above-code appendix to the "base" building 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 "base" energy code. The Stretch Code was last updated in 2017, in conjunction with the 2015 IECC update. The Stretch code remains unchanged with the IECC2018 adoption except to now reference the IECC2018 rather than the IECC2015. A Stretch Code update is planned with the IECC2021 in the MA 10th edition code.

In October 2020, the MA Board of Building Regulations and Standards (BBRS) issued an advisory allowing the use of either RESNET HERS ratings or ICC’s Energy Rating Index (ERI) for residential code compliance in the stretch code or base code.

Additional Resources

Update to Stretch Code and New Specialized Stretch Code

A new climate-focused energy code option was created by the 2021 Climate Act.  DOER is developing this new code alongside the Stretch Energy Code update. However, the specialized code must also include:

Additional Resources

Stretch Code Adoption by Community

Stretch Code Adoption by Community Map and List

Municipalities may choose to adopt the Stretch Code in lieu of the base building energy code. Stretch code adoption is mandatory for designation as a Green Community under the Green Communities Act passed by the Legislature and signed into law in 2008. As of November 16, 2021, 299 municipalities have adopted the Stretch Code. Building code officials have received free code training.

Additional Resources

Stretch Code “Residential Cash Flow Analysis”

In 2016, DOER hired an independent building energy consulting firm to look at the cost-benefit equation of building a representative set of new single-family and multi-family homes to the updated 2015 stretch code. The analyses were updated in August 2017.  There are examples of both gas heated and non-gas heated homes, all of which show that homeowners see a positive cash-flow from day 1 from purchasing a 2015 stretch code home vs. a 2015 base code compliant home.

Click here for analysis

Massachusetts Energy Code Training

The Mass Save statewide energy efficiency program in coordination with the Board of Building Regulation and Standards (BBRS) and DOER is continuing to sponsor training on the building energy code, including the Stretch Code, at various locations around the state. The training is open to all, and developed to serve both building officials and other building professionals (e.g., builders & architects). Training is free for building officials, and counts toward the new BBRS requirement that building officials be trained in energy efficiency. Other building professionals pay a nominal fee for the training, and may receive continuing education units (CEU's) for attending. 

To get information on energy code training and events, click here.



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