Big things are happening in one of the country’s smallest states. This summer, towns, cities, and state agencies throughout Massachusetts have set new benchmarks for decarbonizing the built environment.

On Monday, in her 2023 State of the City Address, Boston Mayor Michelle Wu rolled out an Executive Order (EO) banning fossil fuels in buildings owned by the municipality, making it the first major U.S. city to do so. Under the new EO, “all new buildings will be planned, designed, and constructed so that HVAC, hot water, and cooking systems will not combust or directly connect to fossil fuels for all municipal buildings,” a press release stated. The EO also applies to “major renovations of existing City-owned buildings,” effective immediately, and exempts projects in design, procurement, or construction phases.

Today, about 70 percent of Boston’s total carbon emissions comes from buildings, with 2.3 percent of those emissions coming from municipally-owned buildings. The new EO is a huge step toward “decarbonizing the City’s building portfolio,” the press release continued. The program was made in conjunction with Boston’s Green New Deal Director Oliver Sellers-Garcia, local labor leaders, The Worker Empowerment Cabinet, PowerCorpsBOS, and Boston’s Environment Department, a bureau committed to ensuring a “just transition to a thriving green economy and a citywide Green New Deal.” 

Ten other Massachusetts towns have also pledged to ban fossil fuels as part of a state-level pilot program, all within the Greater Boston area. Cambridge, Massachusetts (one of the ten), passed climate legislation last month that has been dubbed as the “some of the most stringent in the country.” New energy codes in the city of 117,000 people are set to cut its emissions in half by 2030, and 70 percent by 2035. “By US standards, this is one of the most ambitious existing-building emissions regulations to date, and complex details will need to be resolved,” Holly Samuelson, a researcher with the Harvard Center for Green Buildings and Cities, told The Boston Globe.

Mayor Wu’s announcement comes after a major decision in May 2022 to invest $2 billion in decarbonizing Boston Public School buildings as part of her administration’s Green New Deal platform. She’s also championed a program that would “Free the T” to increase public transit ridership that would, as the name suggests, provide fare-free public transit service. Boston is currently experimenting with the idea in a two-year long pilot program, with New York rolling out a similar pilot program for buses this September. If implemented at the city-scale, the model could yield huge environmental and quality of life benefits, though cannot serve as an excuse for poor transit planning decisions, as has been the demise of the fare-free D.C. Streetcar.

Combined, the fossil fuel ban and fare-free public transit pilot program makes Boston a thought leader when it comes to envisioning green strategies. Meanwhile at the state level, earlier this month, Massachusetts Governor Maura Healey announced her plan to build a “green bank” that would finance retrofitting existing buildings and affordable housing taking steps to be climate conscious. The Massachusetts Community Climate Bank, as it will officially be named, will leverage federal dollars and operate under existing affordable housing finanicer MassHousing. The financial institution will provide loans to green projects at better-than-market rates and evaluate the risk of its portfolio differently than a more traditional bank, theoretically allowing it to make loans to riskier projects with ambitious climate goals.  

Green banks aren’t something Massachusetts can take credit for—the oldest one in the U.S. is in Connecticut while the state of New York touts the nation’s largest. What makes the Massachusetts Community Climate Bank a potential trendsetter, however, is that it’s the first green bank in the U.S. dedicated to affordable housing, Governor Healey stated. “This is a really successful and proven model,” David Melly, Legislative Director at the Environmental League of Massachusetts, told local reporters. “It has shown great impacts from an equity perspective in terms of the investments directly benefiting folks that wouldn’t otherwise benefit from standard decarbonization incentives.”

Aside from creative financing mechanisms, Massachusetts is also set to become the first state to put an end to all-glass buildings, giving bird lovers a reason to celebrate. This past July, Massachusetts updated its base building code and stretch code, putting into effect some of the most progressive energy standards in the United States. 

The new codes are set to play a part in the Commonwealth’s goal to “reach 80 percent reduction in all greenhouse gas emissions,” said Sasaki’s Sustainability Coordinator Alison Nash. Katie Raymond, a senior engineer at Epsilon Associates, said the new code “closes a number of loopholes that used to allow for energy tradeoffs in the design of buildings.” 

According to Raymond, the first of the big three ideas contained in the new base building code mandates that Massachusetts architects use “triple glazing, everywhere” to achieve “a maximum whole assembly U-factor (insulative value) of 0.25.” Triple glazing means extra insulation at the cost of extra embodied carbon—the tradeoffs of which are very dependent on the building’s life cycle. Second, Raymond says with the new codes, buildings with 50 percent “glazed wall systems” must employ “full electrification of space heating.” This means architects planning on designing with glass-heavy curtain walls are prohibited from heating their buildings with fossil fuels (with exceptions for high-ventilation buildings). Lastly, Raymond notes “All new commercial construction must be field tested to ensure maximum air leakage rates are not exceeded.”

Payette’s Director of Building Science Andrea Love said the new code’s passing means Massachusetts architects “will not be able to design all-glass buildings anymore. We must look at the code first and then think about design—not the other way around.”

Fossil fuel bans, a new “green bank” for sustainable affordable housing, and restrictions on heavily glazed buildings are all things that other states looking to decarbonize can learn from. While decisions like mandatory triple-glazing and phasing out natural gas are substantial ones, some climate experts may say Massachusetts could go even further.

In AN last May, Senior Director at MASS Design Group Kelly Alvarez Doran emphasized the need to consider embodied carbon, not just operations, in environmental discourse. “For decades, our industry has been focused on energy efficiency. That’s only one part of the problem,” Doran wrote. “Reducing operational emissions involves using less: less space, heat, and cooling and less emissive power sources.”