Brockton · Plymouth County

Can you build an ADU in Brockton?

Brockton is the lightest touch of the towns documented here. It permits ADUs by right on single-family lots in R1 and adds nothing on top of the state floor, which makes it the least obstructed place on this list to build one.

What the state guarantees you

Since 2 February 2025 this applies in every Massachusetts community. A town may be more generous than this. It may not be less.

Rule	What it means
Allowed by right	One ADU in single-family zoning districts, statewideNo special permit and no public hearing for a protected-use ADU
Maximum size	900 sq ft, or 50% of the principal dwelling, whichever is smallerA town may allow larger. It cannot allow smaller
Owner occupancy	A town cannot require itSo you may rent both units, or live in the ADU and rent out the house
Parking	One space at most, and none at all within half a mile of transitA town cannot ask for more than this
Short-term rental	The state leaves this to each townAll six towns documented here ban it, and two of them ban it for the main house too
In force since	2 February 2025Any conflicting local zoning became unenforceable that day

What Brockton adds on top

Rule	In Brockton
Where allowed	By right on single-family lots in the R1 district
Maximum size	900 sq ft, or 50% of the principal dwelling, whichever is smaller
Special permit	Not required where the project meets the criteria
Public hearing	Not required
Owner occupancy	Not imposed
Parking	No mandate beyond ordinary zoning
Design review	No architectural matching requirement

Brockton has three MBTA commuter rail stations, so a large number of parcels fall inside the half-mile transit radius where the state bars any parking requirement at all. Combined with the absence of a hearing, that makes the path from idea to permit shorter here than almost anywhere else on the South Shore. Confirm the codified section with the Department of Planning and Economic Development before you rely on it for a specific lot.

Questions people ask

Does Brockton require a public hearing for an ADU?

No. Where the project meets the criteria, an ADU is allowed by right on a single-family lot in R1 with no special permit and no public hearing.

Does Brockton require owner occupancy for an ADU?

No. Massachusetts prohibits towns from imposing an owner-occupancy requirement on a protected-use ADU, and Brockton adds none.

Do I need extra parking for a Brockton ADU?

Brockton imposes no parking mandate beyond ordinary zoning, and many parcels sit within a half mile of one of the city's three commuter rail stations, where the state bars any parking requirement.