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Updates to Massachusetts' Green Communities Act

Updated: Apr 19, 2023

Understanding the Latest Stretch Code and Specialized Energy Code Options

The Green Communities Act was adopted by the Commonwealth of Massachusetts to fund energy conservation efforts by individual cities and towns. By December 2022, 290 municipalities out of 351 had become Green Communities. Among several requirements for inclusion, and in response to incentives provided by the Commonwealth, these Green Communities are enforcing a ‘Stretch’ Energy Code with greater energy efficiency requirements than the statewide code. A key provision of the Green Communities Act is a requirement to update the statewide energy code every three years, in conjunction with the periodic publication of new editions of the International Energy Conservation Code.

This blog summarizes the most recent update process which is currently underway. Since January 1, 2023 all new low-rise residential construction in Green Communities has been subject to the 2023 stretch code updates. New commercial construction is expected to be required to comply as of July 1, 2023, simultaneous with the adoption of the new 10th edition of the Massachusetts State Building Code (780 CMR). Commercial projects, including high-rise residential buildings, applying for a permit in stretch code communities as of July 1, 2023 will need to comply with the updated Stretch Code.

The 10th edition of the Massachusetts Building Code will be an amended version of the 2021 ICC codes, and the Stretch Code will be an amended version of the 2021 International Energy Conservation Code (IECC 2021). Once adopted all updates to the Stretch Code are automatically enacted in those towns that have chosen to become Green Communities. However, the latest version of the ‘Stretch Code’ will also include its own voluntary appendix, known as the ‘Specialized’ or ‘Net-Zero’ code. Massachusetts jurisdictions must separately choose to adopt the “Specialized” code through a municipal vote.

With this new cycle of codes, collectively known as the 10th edition, Massachusetts has also created an additional level of energy conservation codification. This “Specialized” energy code is a major update to the existing stretch code, resulting in three energy code options for towns and cities in Massachusetts:

10th edition of the Massachusetts Building Code

The Updated Stretch Code

The updated Stretch Code is split into two sections: CMR 22.00 for low-rise residential and CMR 23.00 for commercial and all other construction (including most multi-family). The information below focuses on the commercial stretch code requirements (CMR 23.00), which covers all buildings except for low-rise residential buildings.

Current Massachusetts stretch code requires a 10% improvement over an ASHRAE 90.1 baseline building for buildings over 100,000 SF. The updated Stretch Code has several pathways for compliance, with requirements for buildings of all sizes. The compliance pathways are allowed based on the type of building:

  1. Targeted Performance Pathway, also known as Thermal Energy Demand Intensity (TEDI) – For dormitories, schools, libraries, offices, police stations, post offices, town halls over 20,000 SF. This is an allowable compliance pathway for buildings of any size.

  2. Relative Performance Pathway (ASHRAE 90.21-2019 appendix G) with requirements for electrified space heating – For high ventilation buildings such as labs or hospitals (ventilation over 0.5 CFM / SF).

  3. Prescriptive Pathway (2021 IECC with MA amendments) – May be used for any non-residential building up to 20,000 SF.

  4. Passive House – Can be used for any building of any size.

  5. HERS Compliance – for Group R buildings with multiple dwelling units

The Opt-In Specialized Code (Section CC)

The new specialized “opt-in” code is driving projects towards all electric buildings and renewable energy systems, which is consistent with Massachusetts’s goal to reduce greenhouse gas emissions in buildings.

The Opt-In Specialized Code (Section CC)

For more information on the new energy codes, reach out to F&T to schedule a Lunch & Learn.

Written by:
Ted Hetzel, PE, CPHC, LEED AP BD+C

Sustainability Specialist & HVAC Group Leader


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