Sarah Gustafson
The commonwealth of Massachusetts took a leading step forward in 2024 with the passage of the Affordable Homes Act. The legislation authorizes a record amount of spending on housing over the next five years, $5.16 billion, and many major policy initiatives to counter rising housing costs. One of the most significant policies established by the law will begin Feb. 2, and enables property owners to build accessory dwelling units (ADUs) by-right in all single-family zoning districts statewide.
The Massachusetts Association of Realtors supported this policy throughout the legislative process and stood alongside Gov. Maura Healey to celebrate when it was signed into law. Now, MAR is directing its advocacy efforts towards ensuring that the clearest and least restrictive regulations governing ADUs are adopted by the state. MAR is committed to helping address the housing crisis and the widespread adoption of ADUs will be a crucial tool to deploy to increase housing supply.
What’s an ADU?
ADUs, sometime referred to as in-law apartments, are secondary housing units created by homeowners on their property. As noted by the state, “ADUs can be within an existing primary residence, like converting a basement into an apartment, attached to a primary residence as a new construction addition, or completely detached, like a cottage or converted detached garage in a backyard.”
Under current state law, in towns where ADUs are permitted, they have generally been built by families looking to house relatives. This is largely because the regulatory burdens placed upon homeowners increase development costs for ADUs that far outpace any potential rent return. By allowing them by-right, ADUs will be built more easily and may become an opportunity for homeowners to generate additional income.
The adoption of the Affordable Homes Act, along with the MBTA Communities Law, makes Massachusetts a national leader in essential housing reform.
Allowing ADUs by-right in single-family zoning statewide is expected to generate 8,000 to 10,000 new units of housing, according to the Healey administration. With an estimated need for 20,000 to 25,000 new units of housing a year through 2030 to balance and stabilize pricing, this adoption allows Massachusetts to take a real step towards meeting these goals.
Why They Work
By-right permission for ADUs under this law is essential to their success as a housing option.
This permitting will make ADUs easier to build by reducing red tape for homeowners. This is the most significant way to support ADUs as a viable housing type. If residents are required to work through special permitting processes it would add unnecessary time and money to the building process and create additional liability.
The other key element to success: Maximizing occupancy opportunities.
This will help increase ADU utility for homeowners. ADUs are already a compelling housing type for seniors or multigenerational housing. By allowing homeowners to also rent units to members of the public, ADUs have the potential to serve as another option in the housing market, allowing homeowners to use their homes most efficiently while addressing one of the state’s greatest needs: more housing.
Additionally, dimensional flexibility through a maximum size of 900 square feet and limited scaling requirements related to the size of the single-family home will help more homeowners access ADUs and give them the ability to right-size the structure to their needs. This outcome can be improved by including a provision in the final regulations that allows homeowners whose single-family home or lot that does not conform with current zoning to still benefit from by-right ADU approvals.
What to Watch For
The implementation of this law is at a critical stage.
The Executive Office of Housing and Livable Communities (EOHLC) intends to issue final regulations by the effective date of the ADU law, Feb. 2. EOHLC initiated the regulatory development process on Dec. 6, 2024, by releasing draft ADU regulations.
MAR is watching this process closely and is an active participant on behalf of our members. The public comment period was open from Dec. 20, 2024, through Jan.10, 2025. A public hearing was also held on Jan. 10.
With a history of community opposition to housing in mind, MAR is extremely concerned about the ways in which municipalities may attempt to subvert the intent of this law. Massachusetts has one of the most expensive housing markets in the country because, quite simply, our housing demand far outpaces our supply. That asymmetry was created by decades of abuse of state-granted zoning powers. In its comments, MAR sought to highlight the critical importance of limiting the restrictions that can be placed on homeowners seeking to build ADUs.
As the state seeks to address the unprecedented crisis in housing availability and affordability, MAR will continue to press state leaders to establish innovative and thoughtful solutions, like allowing ADUs by-right in single-family zoning statewide.
Sarah Gustafson is the 2025 president of the Massachusetts Association of Realtors and a Realtor with KW Pinnacle Central in Worcester.
