Mass. DOER proposes a new “opt-in” Specialized Stretch Energy Code and Stretch Energy Code updates

By Karla L. Chaffee

Earlier this week, the Massachusetts Department of Energy Resources (DOER) announced plans, introduced as a “straw proposal,” for updating the state Stretch Energy Code and adopting a new municipal “opt-in” Specialized Stretch Energy Code, designed to address the DOER’s 2021 Climate Act obligation to develop an energy code incorporating net-zero building performance standards.

After the DOER held a virtual briefing webinar on the straw proposal on Tuesday, February 8, it launched a website dedicated to the updates and new code.

DOER highly encourages comments. Submit these electronically to with the subject line “Stretch Code Straw Proposal Comments.” Written comments will be accepted until March 9, 2022.

Stretch Energy Code Update

The most significant proposed update to the residential sections (1-2 family, townhomes, and small multifamily) of the Stretch Code is lowering the compliant HERS (Home Energy Rating System) standard for new builds from HERS 55 to HERS 42 for fossil fuel-heated homes and HERS 45 for electric-heated homes. “Passive” buildings are also considered compliant. (A “passive house” is a building with a super-efficient envelope (@ HERS 34) with high-performance ventilation. According to DOER, over 6,500 passive house units were built in Massachusetts since 2017). According to DOER’s presentation, in 2020, the average new home in Massachusetts was built to a HERS 51 standard. Adoption of the updated Stretch Energy Code will still help a community qualify for a “Green Communities” designation.

The updated commercial standards aim to reduce the life cycle cost of all commercial building types and actually reduce the incremental building costs of large office and lab/office buildings. The proposal includes five pathways to building compliance, depending on the building type developed. The updates also accommodate glass and curtain wall buildings as long as additional embodied carbon reductions are used (i.e., low carbon concrete, carbon sequestering materials, and reused/recycled materials). It also encourages but does not require electrification.

New, Specialized Opt-in Code

The Specialized Opt-in Code provides three options for new residential buildings to meet a “net-zero” compliance standard. Buildings are considered net-zero compliant if one of the following applies:

  • Heated with natural gas or propane and built to HERS 42 and installed with rooftop solar (where unshaded) and pre-wired for future electrification
  • Electric heating installed and built to HERS 45
  • Built to passive house standards and wired for electrification

In all cases, the building must be electric vehicle (EV) ready, with 20% of parking spaces EV wired.

The proposed commercial building requirements also include an EV-ready component. Multifamily (6+ units) must be built to passive house standards. Any commercial building using fossil fuels must also add solar on available roof space and be pre-wired for future electrification.

Next steps

DOER plans to host four geographically targeted public meetings between February 28 and March 8. The first round of public comments is due on the straw proposal by March 9. Any interested parties can sign up to receive Stretch Code updates from the Massachusetts DOER.

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Karla L. Chaffee


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