Updated: September 10, 2024
What changes were made to the definition of ADU?
The definition of “Accessory Dwelling Unit” under Section 1A of Chapter 40A of the General Laws was amended to clarify that the maximum size of an ADU can be no more than ½ of the gross floor area of the principal dwelling, or 900 sq. feet, whichever is smaller. The definition was also amended to remove explicit statutory authority for municipalities to impose owner-occupancy requirements and prohibits municipalities from unreasonably restricting the creation or rental of an ADU that is not being used as a short-term rental, as that term is defined in the room occupancy excise laws (Section 1 of Chapter 64G of the General Laws).
When do the revisions in MGL c. 40A Sections 1A and 3 related to ADUs take effect?
The change to Section 3 of Chapter 40A of the General Laws is effective Sunday, February 2, 2025, which is 180 days from the effective date of the Affordable Homes Act.
What happens if my town’s zoning is not consistent with MGL c. 40A Section 3 after February 2, 2025?
After Sunday, February 2, 2025, zoning provisions that are inconsistent with MGL c. 40A Section 3 may be unenforceable. An application for an ADU in a single-family zoning district that is consistent with MGL 40A definition and requirements should be accepted and acted on consistent with state statute. Municipalities are encouraged to review their zoning and identify provisions that are not consistent with the law.
If my community is amending zoning to add the revised definition and process to allow ADUs as of right in single-family zoning districts, does it qualify for a simple majority to approve zoning at our legislative body or 2/3 super majority?
Amending zoning to allow for ADUs as of right under Chapter 40A is a simple majority vote. Please consult with your town counsel or city/town solicitor for their legal advice. You can find Guidance on voting thresholds for zoning here: Voting Threshold Guidance | Mass.gov
Is there a requirement for EOHLC to review and approve our ADU zoning?
No, the statute does not require EOHLC to review or approve ADU zoning.
Will EOHLC issue guidelines or regulations to administer the ADU law?
EOHLC is developing regulations and will continue issuing guidance, including this FAQ. Please check back here from time to time to get an update on the schedule for issuing draft regulations and opportunities for public comment.
I would like to build an ADU on a property I own. How can I get a permit to build an ADU?
The new law permitting ADUs as of right does not take effect until February 2, 2025. As local zoning and procedures for review will vary from municipality to municipality, we recommend that you contact your municipality’s building department. They can share the status of local zoning rules, processes, and building standards that are specific to your city or town and to your property.
EOHLC will be working with municipalities across the state to ensure they have information on the rollout of the ADU policy in the coming months. Please bear in mind that your municipality may not yet have all the answers as we work together to implement this new law.
Where can I find information about financial resources such as loans and financing to build an ADU on a property I own?
We suggest that you talk to your local bank or other trusted financial institution, and to a building contractor. EOHLC will work with partner agencies, programs, and banking industry professionals to provide an overview of various ways in which property owners can finance the construction of ADUs.