The building sector in Boston accounts for more than 70% of the City’s greenhouse gas emissions, most of which is the result of heating loads and choices for building heating fuel (electric versus fossil fuels). Therefore, on Wednesday, April 5, 2023, the Boston City Council officially adopted the state Department of Energy Resources’ (“DOER”) Municipal Opt-In Specialized Stretch Energy Code (“Specialized Code”) by a vote of 8 to 4. The Specialized Code is a series of additional requirements, or appendices, to the Massachusetts Stretch Energy Code (“Stretch Code”) already in effect in Boston.¹

The Specialized Code will affect all new building construction within the City (after January 1, 2024) and existing buildings that propose significant renovations, requiring that all such buildings be Net-Zero Buildings upon completion of construction.

DOER developed the new Specialized Code to be consistent with the Act Creating a Next-Generation Roadmap for Massachusetts Climate Policy that was passed by the State Legislature in 2021 (MGL Session Laws of 2021, c. 8 §31), which requires that the State meet a net-zero greenhouse gas emission standard by 2050 via incremental emission limits that get stricter every five (5) years between now and the final deadline. The new measures will take effect on January 1, 2024, and be enforceable by the City’s Inspectional Services Department.

The Specialized Code will affect all new building construction within the City (after January 1, 2024) and existing buildings that propose significant renovations, requiring that all such buildings be Net-Zero Buildings upon completion of construction. The Specialized Code adopts the following definition of a Net-Zero Building:

A building which is consistent with achievement of MA 2050 net zero emissions, through a combination of highly energy efficient design together with being an all-electric or Zero Energy Building, or where fossil fuels are utilized, a building fully pre-wired for future electrification and that generates solar power on-site from the available Potential Solar Zone Area.

This means that, while not all new buildings or major renovations need to be emission free in their own right immediately, they must meet one of three “pathways” for compliance. The options are: the Zero Energy pathway, the All-Electric pathway, or the Mixed-Fuel pathway. The Specialized Code, like the Base Code and the Stretch Code, divides buildings into two categories, and recognizes slightly different standards depending upon the building: 1) low-rise residential, and 2) commercial (and all other). The Net-Zero Building Performance Standards are found in 225 CMR 22 Appendix RC and 225 CMR 23 Appendix CC, for residential and commercial construction respectively.

Practical considerations for meeting these new requirements include the following: ensuring that your builder or contractor is meeting the new metrics for required heating and cooling energy (ideally using all-electric heating, cooling, and hot water), wiring at least 20% of residential and business parking spaces for electric vehicle charging, pre-wiring for future electric systems (i.e. equipping the building with the wiring to eventually eliminate fossil fuels and be converted to all electric usage), ventilation energy recovery, and/or installing solar.

Current boards and property managers are going to be more concerned with existing buildings and whether or not proposed renovations to condominium complexes are significant enough to trigger the new standards. The Stretch Code, and therefore the Specialized Code, is triggered for low-rise residential renovations if:

1) Additions are over 1,000 sf;

2) Additions exceed 100% of the conditioned floor area of the existing dwelling unit (i.e. if the house or building more than doubles in size); or

3) Alterations where more than 50% of the home is renovated and/or reconfigured (“Level 3 Alterations”), as defined in the International Existing Building Code (IEBC 2021).

For commercial and all other buildings, the Stretch and Specialized Codes are triggered when: an addition will exceed 20,000 sf, an addition exceeds 100% of the size of the existing building, or there is a change of use or occupancy. In these circumstances, commercial and all other buildings are expected to meet the standards applicable to new construction. Where additions are smaller, the construction must comply with Sections C401.3, C402 through C406, and C408 of the regulations (the Commercial Energy Efficiency standards, 225 Mass. Code Regs. 23.4.00). There is an exception for historic buildings, as long as a signed report verifying the historic significance of the property is submitted to the building official.

The opinions about whether or not these changes will include significant costs for projects seems to be divided by perspective. Some assert that the more stringent requirements will increase project costs by 10% or more by requiring triple glazing of windows, mandatory electrification, and air infiltration testing requirements, etc. Others, by contrast, claim that the financial and practical impacts of these regulatory changes will be fairly limited. They argue that most new construction and significant renovation projects have enough incentives to meet these standards even without the regulatory backstop, as energy efficiency decreases building operational costs (particularly over the long term), can increase marketability, and largely reflect the construction materials that are readily available on the market today.

Regardless of these differences of opinion, the fact is that the City of Boston will now require buildings to meet these standards and other jurisdictions are likely to follow. The Stretch Code that was first promulgated in 2009 has now been adopted by more than 300 of the State’s 351 municipalities. Even if the Specialized Code does not end up being as successful, it is still likely to be adopted in a significant portion of the State and, like the Stretch Code, become the new norm.

¹For clarification, there are three levels of Building Energy Code Requirements in the State of Massachusetts, including the City of Boston: the Base Code, the Stretch Code (developed in 2009), and the Specialized Stretch Code (developed in 2022). Each of these levels imposes increased standards for energy efficiency.