Fossil Fuel Free Demonstration

The City of Cambridge has adopted an ordinance that will require future buildings to be fossil fuel free. City Council voted to approve the act on August 7, 2023. The Massachusetts Department of Energy Resources (DOER) approved Cambridge's ordinance in December 2023, and it will go into effect on March 22, 2024. 

The new ordinance will impact:

  • new buildings, and
  • existing buildings that undergo a major renovation

Exceptions from the new rules were made for some building and equipment types. You can read the full act here


Why are we doing this?

  • The state legislature created a program for ten communities to implement fossil fuel free requirements, and Cambridge is one of the ten communities allowed to participate.
  • Making buildings fossil fuel free means healthier homes and workplaces.
  • It will help Cambridge reach our climate goals.

Fossil Fuel Free Demonstration Webinars

The City of Cambridge hosted several webinars to educate residents and building owners about the Fossil Fuel free Demonstration Project and hear your feedback. We used the feedback to inform our decisions about which building types and equipment to exempt from the rule. To view the past webinar slides, click here. To view the July 10, 2023 webinar please click here to view a recording

For translated slides of this webinar, please click the link below:


In August 2022, the state passed An Act Driving Clean Energy and Offshore Wind, creating the Municipal Fossil Fuel Free Building Demonstration Program.

  • This program allows ten communities to create fossil fuel-free requirements for:
    • New buildings, and
    • Major renovations (typically projects where 50% or more of the whole building is being renovated).
  • For this program, the Massachusetts Department of Energy Resources (DOER) created regulations and a suggested ordinance.

Cambridge was selected as one of the ten communities for this program because:

  • By submitting a petition to the state in April 2022, the City Council had already requested the ability to enact such requirements, in line with our Net Zero Action Plan priorities.
  • The state required that a community meet specific affordable housing criteria, and Cambridge meets these: at least 10% of our housing stock is affordable housing.

DOER reviewed the City's proposed fossil fuel free ordinance and issued its approval on December 22, 2023. DOER will also later collect building permit data to assess program impacts.

The Fossil Fuel Free Requirements

The new fossil fuel free ordinance will impact two types of construction: new buildings and major renovations. (Major renovation is defined by the program regulations and typically applies to projects where 50% or more of the whole building's area is undergoing reconstruction). The requirements will apply to projects seeking a building permit on or after March 22, 2024.

  • Hospitals, medical offices, and labs are specifically exempt from the requirements by state law.
  • Exceptions were made for certain building types and equipment.
  • For buildings undergoing major renovation, no new fossil fuel-using equipment can be installed in the permitted work area.

You can read the full act here.

What does it mean to be fossil fuel free?

  • Fossil fuel free means that a building does not use any of these fuels to operate:
    • Oil
    • Gas, or
    • Other fossil fuels (including synthetic equivalents)
  • Systems or appliances that commonly use fossil fuels include:
    • Heating
    • Hot water
    • Cooking
    • Clothes drying
  • Alternatives to fossil fuels are all-electric systems, like heat pumps.