Mayor Wu bans fossil fuels in new City of Boston buildings and major renovations

Boston Mayor Michelle Wu on Monday signed an executive order banning the use of fossil fuels in new construction and major renovations of city buildings.

"This is a major undertaking," Wu said during a ceremony at City Hall. "It's many, many school buildings, and public housing units, and boilers, and appliances, and that is part of why it's taken us until this point in our administration to be sure that we could deliver."

The executive order eliminates the use of common energy sources such as natural gas and heating oil in new municipal buildings. It also bars their use in renovations that affect 75% or more of a building's square footage.

Any project that replaces a building's HVAC system, hot water system or cooking equipment also must eliminate fossil fuel sources and combustion.

Wu said the move is part of the city's goal of achieving carbon neutrality by 2050. Over 70% of Boston's total carbon emissions come from buildings.

"Wherever we can, at whatever scale is possible, we have to be accelerating those deadlines," Wu said.

Local developers praised the new executive order, which for now affects only public buildings, not private projects.

Tamara Small, chief executive of the commercial real estate development association NAIOP Massachusetts, said the private sector will watch carefully how the city deals with the challenge of developing all-electric buildings.

"The lab sector is particularly difficult to get to 100% electric," she said. "So seeing how the city — with perhaps some additional public sector resources — could get there, will be helpful for us."

Boston's current capital plan includes over $130 million for developing decarbonized buildings and overhauling old ones.

"I think it will cost the city more money, but in the long run, I think it's a good investment," said Larry DiCara, a former Boston city councilor and real estate attorney.

While this executive order applies only to public buildings, a major rule change around fossil fuels in private developments kicks in next year.

Boston recently opted in to a new state specialized code that requires new construction — even if currently hooked up to natural gas — to be wired for future all-electric use.

Those new regulations take effect Jan. 1