Massachusetts Specialized Stretch Energy Code

In 2022, Massachusetts DOER approved a statewide Specialized Stretch Energy Code that cities and towns could adopt to boost the energy efficiency of new buildings and help lay the groundwork for electrification. All compliance pathways under the Specialized Code are designed to ensure new construction that is consistent with a net-zero Massachusetts economy in 2050, primarily through deep energy efficiency, reduced heating loads, and efficient electrification. The Specialized Code requires all new buildings to be designed with electric service and wiring sufficient for future electrification of space and water heating as well as any combustion equipment appliance loads.

The Specialized Code builds on the efficiency and clean energy standards in the state’s general Stretch Code and pushes new construction towards deep energy efficiency, reduced heating loads, consumer protection, and efficient electrification. Use of fossil fuels, such as gas or propane, under the Specialized Code is permitted, but comes with additional requirements for on-site solar generation and pre-wiring for future electrification of any fossil fuel using equipment.

The Specialized Code can be summarized generally as follows:

1. No additional requirements beyond the Stretch Code for additions, alterations, or renovations.
2. No additional requirements beyond the Stretch Code for all-electric new construction, except for multifamily housing over 12,000 square feet.
3. Any new residential or commercial construction using fossil fuel combustion systems (except multifamily housing over 12,000 square feet) will need to:

• Provide pre-wiring for future appliances and HVAC electrification.
• Install a minimum amount of solar (with some exceptions for shading).
• Homes over 4,000 square feet must install enough solar or other renewables to offset all the home’s energy use.

1. Any new multifamily housing over 12,000 square feet will need to meet Passive House standards.

Outside of the specialized code, Massachusetts has a Stretch Code emphasizing energy performance. The Stretch Code is typically updated every few years, with the most recent update taking effect in 2023. Where neither stretch code has been adopted, the ninth edition of the Massachusetts State Building Code (2018) adopts the 2015 IECC and ASHRAE Standards 90.1-2013, with strengthening amendments. As of early 2024, the tenth edition of the base code was in public consultation.

Noted adoptions

In October 2023, the city of Needham voted to adopt the new specialized code, effective July 1, 2024.

In March 2023, the city of Boston voted to adopt the new specialized code, effective 2024.