Accessory Structures in Brookline, MA (2026)
4 verified accessory structures rules for Brookline, Massachusetts, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Brookline updated its ADU bylaw (§ 4.05) in 2024 to comply with MGL c. 40A §3. One ADU by right on single-family lots is allowed up to 900 sq ft or 50% of principal floor area. Owner-occupancy requirements removed. FAR cap for ADUs eliminated.
Brookline ADU Rules (2024 Amendment)
Few RestrictionsShed Rules
Accessory structures in Brookline must comply with dimensional requirements under the Zoning By-Law (Article V) and may require building permits. Structures in the Floodplain Overlay District require a Floodplain Development Permit.
Brookline Shed and Accessory Structure Rules
Some RestrictionsGarage Conversions
Brookline's 2024 ADU bylaw amendment eliminates the prior 5-year age requirement for garage conversions to ADUs. Conversions require a building permit and must meet 780 CMR standards. Detached garage ADUs must comply with ZO §§ 5.63 and 5.72.
Brookline Garage Conversion Rules
Some RestrictionsMass. Gen. Laws Ch. 40A Sec. 3A (MBTA Communities — Multi-Family Zoning)
Section 3A. (a)(1) An MBTA community shall have a zoning ordinance or by-law that provides for at least 1 district of reasonable size in which multi-family housing is permitted as of right; provided, however, that such multi-family housing shall be without age restrictions and shall be suitable for families with children. For the purposes of this section, a district of reasonable size shall: (i...
Carport Rules
Brookline's Zoning By-Law treats a detached carport as an accessory building. Under the Article V dimensional rules and the Building Department's Storage Shed/Accessory Structure FAQ, an accessory structure must sit at least 6 feet from any side or rear property line and at least 6 feet from the principal residence, may not stand in any front-yard setback, and requires a building permit; relief from the 6-foot setback or front-yard placement is only available by Special Permit from the Board of Appeals.
Brookline Carport Rules
Some RestrictionsLooking for Norfolk County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Brookline city rules.
Accessory Structures in Norfolk County →