Accessory dwelling units are now permitted by-right statewide in Massachusetts thanks to the Healey-Driscoll Administration’s Affordable Homes Act, signed into law by Governor Maura Healey in August 2024.
Sometimes called tiny homes or in-law suites, ADUs are small, independent living spaces located on the same lot as a principal dwelling in a single-family residential zoning district. Garages, attics, and basements can be converted into ADUs, or an ADU can be a newly constructed detached cottage or addition onto the primary home, with a separate entrance.
The undersupply of housing in Massachusetts has dramatically increased housing costs in recent years. ADUs are part of the solution to build more homes and drive down costs for tenants and homebuyers. As of Sunday, Feb. 2, ADUs less than 900 square feet can be built by-right in single-family zoning districts statewide, and the Executive Office of Housing and Livable Communities estimates that 8,000 to 10,000 ADUs can be constructed over the next five years thanks to this simplification of the ADU permitting process.
The Massachusetts Healthy Aging Collaborative advocated for the Affordable Home Act and the ADU provisions, among others.
ADUs can have profound effect for homeowners and their families. They can allow older adults to age in place and remain close to their grandkids and children. ADUs can also offer independent living for young adults with special needs.
Following a public comment period, EOHLC has now issued final regulations intended to help cities and towns adjust their local ordinances and allow for ADUs by-right. You can visit Mass.gov/ADU to learn more specific details about the ADUs by-right policy.
Municipalities who need assistance drafting, conducting community planning, and enacting local ADU rules may apply for funding through the Community One Stop for Growth.
Residents interested in developing an ADU should contact their city or town services who will be able to give them an understanding of the local rules and how they can apply for a permit. Additionally, residents seeking to build an ADU for people with disabilities or people over 60 may be eligible for no-interest financing through the state’s Home Modification Loan Program.