Specialized Stretch Energy Code

Specialized Stretch Energy Code

Cambridge has adopted the Massachusetts Specialized Stretch Energy Code, effective July 1, 2023. This new Specialized Stretch Code was developed by the Commonwealth in 2022 as an option for municipalities. The Specialized Code will require builders, for both new construction and major renovations, to meet high performance standards, prepare buildings for all-electric heating and cooling, and make parking ready for electric vehicle chargers. The adoption of the Specialized Code is part of the goals of Cambridge’s Net Zero Action Plan.

Upcoming Webinars - July 2023

To assist builders, building owners, and interested Cambridge residents in understanding the implications of this new law, we are partnering with MassSave in presenting two webinars to explain the basics of the Stretch Code, along with the further requirements of the Specialized Code adopted by Cambridge and others. Use the links below to register:

  • Webinar 1: Commercial Focus -View the Recording
    Tuesday, July 11, 2023 4:00 PM - 5:00 PM EDT
  • Webinar 2: Residential Focus - View the Recording
    Wednesday, July 12, 2023 4:00 PM - 5:00 PM EDT


There are three levels of building energy code in Massachusetts: the Base Code, the Stretch Code, and the Specialized Stretch Code. All apply to new construction and major renovations, for both commercial and residential buildings. Cambridge had adopted the original Stretch Code in December 2009, making it one of the first municipalities in the state to do so. The Stretch Code has since been adopted by 296 cities and towns in Massachusetts.

The Massachusetts Department of Energy Resources (DOER) updated the Stretch Energy Code in 2022, increasing the energy performance required of new and renovated buildings. In addition, the Commonwealth’s Climate Act of 2021 directed DOER to develop a municipal opt-in specialized code that advanced net-zero building performance.

The City of Cambridge participated in the development of the codes, and they were finalized by DOER in December 2022. (More information about the development of the Specialized Code is available here). Cambridge City Council voted to adopt the Specialized Code on January 23, 2023.

Key Requirements

Below is a brief overview of the Specialized Code requirements, including the differences from the Stretch Code. For further information, please see DOER’s Final Code Language and summary document.

Commercial buildings

  • Both the Specialized and updated Stretch Codes create a new metric regulating the amount of heating and cooling energy required. Builders can use this metric or Passive House standards to comply. There are alternative standards for labs, hospitals, and small commercial buildings (under 20,000 sq. ft.).
  • The Specialized Code encourages the use of all-electric heating, cooling, and hot water. Buildings that use fossil fuel systems must be pre-wired for future electric systems and have solar.
  • Both codes require 20% of residential and business parking spaces to be wired for electric vehicle charging.

Residential buildings

  • The Specialized Code requires that buildings with fossil fuel systems must be pre-wired for future electric systems, and, for smaller buildings, must have solar.
  • The Specialized Code requires that multifamily buildings over 12,000 sq. ft. meet Passive House standards or net-zero home performance scores.
  • Both levels of code require that any parking must be wired for at least one EV charger in small buildings, or 20% of spaces in multifamily buildings.

Fossil-Fuel Free Pilot

In 2022, the Legislature authorized a pilot for up to 10 municipalities to eliminate the use of fossil fuels in new construction and major renovation. Cambridge submitted a Home Rule Petition requesting this authorization in April 2022, thereby making it one of the 10 Prioritized Communities. Learn more about the Fossil Fuel Free Demonstration Project and next steps here.

For More Information

Please contact the Inspectional Services Department at (617) 349-6100.