Housing and Research

Accessory Dwelling Units

Accessory dwelling units (ADUs), also called "accessory apartments," are small, secondary living spaces located on the same lot as a principal dwelling unit. ADUs can be attached to an existing home or detached on the same lot.

Apply for SRPEDD's ADU Technical Assistance Program here

Accessory dwelling units can support downsizing seniors, recent graduates, small families, and individuals with disabilities.

As a part of the Affordable Homes Act, signed into law on August 6th, 2024, ADUs are now allowed by right in Massachusetts. The amendments to Chapter 40A Section 3 and regulations (760 CMR 71.00) became effective on February 2nd, 2025.

ADUs allow homeowners to create secondary living spaces on their property. ADUs broaden the range of housing choices in a community by increasing the number of small dwelling units available for rent.

Municipal staff should consult with their City Solicitor or Town Counsel for legal advice.

2026-2027 ADU Technical Assistance Program

SRPEDD received an award through the Community One Stop for Growth to provide regional ADU technical assistance to its member communities. Please complete the form below if you are interested in receiving technical assistance.

Applications will be accepted on a rolling basis through December 31st, 2026. All projects will be completed by June 30th, 2027. The total dollar amount of technical assistance provided by SRPEDD will vary based on the requested work and timeline.

Links and Resources

EOHLC SRPEDD Presentation Slides

Missed the 01/08 Meeting? Download the slide deck presented by Claire Morehouse, EOHLC.

EOHLC ADU Resource Page

Stay up to date on updates from EOHLC on Accessory Dwelling Units.

760 CMR 71.00

Read the regulations, "Protected Use Accessory Dwelling Units."

ADU Frequently Asked Questions - Answered

Read answers to frequently asked questions about ADUs - provided by EOHLC.

EOHLC AHA Resource Page

Stay up to date on updates from EOHLC on the Affordable Homes Act.

EOHLC ADU Model Bylaw

Read the model ADU bylaw developed by EOHLC, MAPC, and MHP.

EOHLC ADU Incentives Program

Fill out the form if you are interested in learning more about EOHLC's ADU Incentives Program.

Read the AHA Fact Sheet

Read the fact sheet on the recently passed Affordable Homes Act.

What can Communities Regulate?

Under the new law (which amends § 1A and § 3 of Chapter 40A "the Zoning Act"), communities cannot unreasonably restrict or require a special permit or other discretionary zoning approval process to construct an ADU. EOHLC may issue guidelines or promulgate regulations on further administration of by right ADUs.

Communities can regulate ADUs by:

Imposing Site Plan Review;
Imposing restrictions on short-term rentals;
Setting basic size and dimensional standards; and
Setting "other reasonable restrictions."

Communities cannot regulate ADUs by:

Requiring a special permit;
Requiring more than 1 parking space for an ADU within a half-mile of a transit station, including commuter rail;
Imposing owner-occupancy restrictions;
Prohibiting rentals (except for short-term rentals); or
Setting other unreasonable restrictions.

Under the law, a special permit is required to construct a second ADU on a property in a single-family residential zoning district. ADUs are subject to reasonable regulations, including 310 CMR 15.000 ("Title 5") and MGL c. 131 § 40 / 310 CMR 10.00 ("The Wetlands Protection Act" and associated regulations).