ADU Rules in Brookline, Massachusetts

Brookline is a Norfolk County town of about 63,000 that is almost entirely surrounded by Boston but is an entirely separate municipality. Despite Boston's efforts to annex it in the 19th century, Brookline has maintained its independent status. Birthplace of President John F. Kennedy (John F. Kennedy National Historic Site is on Beals Street), Brookline is an affluent, urban community with a strong preservation culture. Massachusetts enacted a statewide ADU law (Chapter 150, Acts of 2024) requiring ADUs by right in single-family zones.

CRITICAL: Brookline Is NOT Boston

Brookline is a separate town, not part of Boston. Despite being surrounded by Boston, Brookline has:

• Its own Town Meeting government
• Its own Zoning Bylaw (administered by Brookline's Building Department)
• Its own permit process

Do not use Boston permits for Brookline properties.

Massachusetts Statewide ADU Law (2024)

Massachusetts Chapter 150, Acts of 2024 requires municipalities to allow ADUs by right in single-family residential zoning districts. Verify how Brookline has implemented this law.

Brookline Zoning Bylaw

The Town of Brookline Zoning Bylaw governs all land use in Brookline.

Permitted ADU Types

Per Massachusetts ADU law and Brookline zoning (verify current standards):

• Basement and interior conversions: Common in Brookline's Victorian and Edwardian housing
• Attached ADUs: With separate entrance
• Detached ADUs: In eligible zones (Brookline is dense — rear yard space limited)
• Carriage house conversions: Where structures exist

Size Limits

Per Massachusetts ADU law:

• ADU cannot exceed smaller of: primary dwelling or 900 square feet
• Brookline zoning may have additional standards — verify

Setbacks

Per Brookline residential zone:

• Rear: Minimum setback
• Side: Minimum setback

Historic Districts

Brookline has local historic districts and is home to the JFK National Historic Site (NHS). Properties in Brookline's local historic districts require review by the Brookline Preservation Commission.

Massachusetts Wetlands Protection Act

Properties near Muddy River, Leverett Pond, Jamaica Pond (just over the Boston border), or other waterways are subject to Massachusetts Wetlands Protection Act. Brookline Conservation Commission review required.

MBTA Communities

Brookline is served by the MBTA Green Line (C and D branches). MBTA Communities law applies.

Permit Process

1. Verify jurisdiction: Confirm your property is in Brookline (not Boston)
2. Verify zoning and state ADU law: Brookline Building Department
3. Historic Preservation review: If in a local historic district
4. Conservation Commission review: If near wetlands or waterways
5. Submit plans: Brookline Building Department
6. Building permit and inspections
7. CO: Required before occupancy

Contact

Town of Brookline Building Department 333 Washington Street, Brookline, MA 02445 Phone: (617) 730-2107 Website: brooklinema.gov/building

Disclaimer: Brookline is a separate town from Boston. Massachusetts statewide ADU law (2024) applies. Verify current standards with Brookline's Building Department before starting any project.