Today, Mayor Michelle Wu visited the Brian Honan Apartments in Allston-Brighton to announce the City’s intention to adopt a new, green building code that will strengthen energy efficiency requirements for new construction in Boston.

To achieve this, Mayor Wu will file an ordinance with the Boston City Council to adopt the State Department of Energy Resources’ Municipal Opt-in Specialized Stretch Energy Code, a transformative green update that will further reduce climate-polluting emissions in buildings in municipalities that have adopted the code across the state.

Additionally, Mayor Wu announced the new Large Building Green Energy Retrofits Program administered by the Mayor’s Office of Housing, a grant program supported by $10 million of the American Rescue Plan Act (ARPA) funding to be used to foster energy performance improvements for affordable housing developments.

This program will significantly reduce the energy consumption and carbon footprint of Boston’s existing affordable housing. Together, these efforts will further the City’s work to increase energy efficiency, reduce greenhouse gas emissions from buildings, transition away from fossil fuels, and support the City’s carbon neutrality goals.

“Building a Green New Deal city means improving on our existing infrastructure as well as investing in future resilient development,” said Mayor Michelle Wu. “This new green building code will help ensure that we set the foundation for healthy, resilient growth throughout our neighborhoods.”

“Our focus is taking decisive action now to support our climate, advance justice and bolster livability throughout the City of Boston for all of our residents. To advance Boston’s Green New Deal, we are tackling building decarbonization from all different angles, using all of the tools at our disposal,” said Green New Deal Director Oliver Sellers-Garcia. “By both adapting existing buildings and setting new energy standards for new buildings, we are taking an all of government approach to reducing emissions in more buildings to ensure our climate’s health and our city’s quality of life.”

Municipal Opt-in Specialized Stretch Energy Code

The Specialized Stretch Code was created along with an updated Stretch Energy Code in December 2022. The stretch energy code applies to nearly 300 Green Communities in Massachusetts, including Boston, and sets energy efficiency requirements for new construction and major renovations. The new, updated Stretch Energy code requires energy conservation measures to reduce heating and cooling demand. It creates a strong standard to ensure buildings are more resilient to power outages while enabling efficiency, electrification, and affordability.

In Boston, 70 percent of greenhouse gas emissions come from the building sector. The impacts of these emissions contribute to global climate change and local air pollution that disproportionately impacts low-income residents and communities of color in Boston. The updated energy code will deliver the long-term benefits of improved air quality, lower energy costs, reduced carbon emissions, and enhanced thermal comfort to residents. Research shows there is little-to-no cost increase for building efficient and fossil fuel-free multifamily housing.

“The adoption of the state’s Specialized Stretch Energy Code is an important part of Boston’s work to decarbonize our buildings and reduce our carbon footprint,” said Reverend Mariama White-Hammond, Chief of Environment, Energy and Open Space. “I’m grateful to be a part of a Green New Deal City where we prioritize affordable housing in our decarbonization work.”

The specialized code expands upon the current policy by requiring mixed-fuel buildings, or those using fossil fuels, to add wiring for future conversion to electrification and to install solar. The specialized code will result in most new buildings adhering to a highly efficient, all-electric standard. The specialized code includes three pathways to comply, including:

Zero Energy: All stretch code efficiency requirements are to be met, and on-site renewable energy generation is equal to or greater than the building’s annual energy use. Any fossil fuel use must be pre-wired for electrification.

All-Electric: This pathway requires all stretch code efficiency requirements to be met and for the property to utilize no fossil fuels, except for backup generators, on-site vehicles, or outdoor equipment fueling.

Mixed-fuel: Gas or fossil fuels are allowed if all stretch code efficiency requirements are met and the building is pre-wired for electrification. On-site solar must also be added to the property where feasible. New homes over 4,000 sq. ft. cannot use this option.

If approved by the City Council all multifamily housing over 12,000 sq. ft. must achieve Passive House certification in addition to meeting one of the above pathways beginning in January 2024.

Affordable housing green retrofits

While adopting the new greener specialized code creates a strong baseline for new buildings to be energy efficient, the City of Boston is also being intentional about supporting existing properties to bolster energy efficiency through retrofits. To support this work, Mayor Wu announced the Mayor’s Office of Housing’s new Large Building Green Energy Retrofits Program that will provide up to $50,000 per unit for deep energy retrofits for income-restricted buildings with 15 or more units in Boston. In coordination with the launch of this program, the Mayor’s Office of Housing is also offering up to $10,000 in technical assistance grants to support building owners in learning about their building’s energy use, and laying out a roadmap to achieving a deep energy retrofit of their building and BERDO compliance.

There are a variety of green energy retrofits possible for income-restricted housing developments in Boston, accounting for the building’s age, condition, and usage. Standard retrofitting measures include:

Installing energy-efficient lighting and appliances

Upgrading insulation and weatherization to prevent heat loss

Replacing outdated heating, ventilation, and air conditioning (HVAC) systems with more efficient models

Installing solar panels or other renewable energy sources

Upgrading windows and doors to be more energy-efficient