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Final Regulations for the Stretch Code and the Opt-In Specialized Code are Adopted

On December 9, 2022, the Department of Energy Resources (DOER) filed its final regulations for the Stretch Code, 225 CMR 22.00 and 225 CMR 23.00, with the Secretary of Commonwealth. Under Chapter 8 of the Acts of 2021 (the “Climate Act of 2021”), authority to promulgate the Stretch Code was moved from the Board of Building Regulations and Standards to DOER. The Climate Act of 2021 also required development of the Municipal Opt-in Specialized Code (Specialized Code). The Stretch Code applies in municipalities that are a Green or Stretch Community, of which there are 299 in the Commonwealth. No municipal action is necessary for existing Stretch Code municipalities to implement the updates to the Stretch Code.

A municipality must opt-in to the new Specialized Code. In towns, this will require placing the opt-in on the warrant to obtain Town Meeting approval. DOER recommends that if a town votes to opt-in to the Specialized Code, the requirements take effect for new building permit applications beginning on the next January 1st or July 1st, whichever is a minimum of 6 months after the Town Meeting vote. This delay in the effective date of the Specialized Code will provide a transitional period for developers and municipal staff alike, particularly allowing municipal staff to receive training on the new requirements.

Changes in the updated Stretch Code touch on lowering Home Energy Rating System Index (HERS) scores, including wiring in all new construction for electric vehicle charging, and placing more strict requirements on alterations and additions to existing buildings. For example, under the Stretch Code, beginning January 1, 2023, a new single-family home utilizing mixed-fuel must have a HERS rating of 52; starting July 1, 2024, a new single-family home utilizing mixed-fuel will be required to have a HERS rating of 42. As for commercial buildings, the Stretch Code has been applicable to buildings over 100,000 square feet and did not apply to additions or alterations, but beginning July 1, 2023, the commercial Stretch Code will apply to buildings of all sizes, and additions and alterations to existing buildings.

If a municipality opts-in to the Specialized Code, an example of a more stringent requirement is that all new single-family homes over 4,000 square feet will be required to use All-Electric or Zero Energy; All-Electric requires that the house have a HERS of 45 or that it be a Passive House. Zero Energy would require a HERS of 0, meaning a HERS of 42 plus solar energy, or Passive House (Phius Zero). Relative to multi-family developments, under the Specialized Code starting in January 2024, Passive House will be required for all residential development over 12,000 square feet, if a municipality opts-in. These are just a few examples of differences in the updated Stretch Code and the stricter requirements of the Municipal Opt-in Specialized Code.

On January 5, 2023, DOER released a draft Technical Guidance to assist in implementation of the updated Stretch Code and the new Municipal Opt-in Specialized Code. DOER is accepting written comment on the draft Technical Guidance until February 2, 2023, at 5 p.m. If you would like assistance crafting comments, please do not hesitate to contact us. More information on the updates to the Stretch Code and the new Municipal Opt-in Specialized Code is available at


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