Accessory Structures in Plymouth County, MA (2026)
3 county-level rules, plus city-specific rules for 1 city in Plymouth County, Massachusetts.
Verified from official government sources
ADU Rules
Since February 2025 an accessory dwelling unit up to 900 square feet is allowed by right in every single-family zone across Plymouth County. State law, not town discretion, made it: no special permit can be required to build one.
Plymouth County ADU (Accessory Dwelling Unit) Rules
Some RestrictionsMGL c.40A §3
No zoning ordinance or by-law shall prohibit, unreasonably restrict or require a special permit or other discretionary zoning approval for the use of land or structures for a single accessory dwelling unit, or the rental thereof, in a single-family residential zoning district
Shed & Carport Rules
A small shed skips the building permit everywhere in Plymouth County. The state code exempts a one-story detached storage shed of 200 square feet or less, so a backyard shed in Plymouth or Brockton needs no building permit.
Plymouth County Shed & Outbuilding Rules
Few Restrictions780 CMR 51.00 R105.2
One-story detached accessory structures used as tool and storage sheds, playhouses, and similar uses provided that the floor area does not exceed 200 ft2
Tiny Homes
A tiny home's rules in Plymouth County turn on its foundation. Built on a permanent foundation at 900 square feet or less, it now qualifies as a by-right accessory dwelling unit; on wheels, it is an RV that zoning does not treat as a permanent home.
Plymouth County Tiny Home & Small Dwelling Rules
Some RestrictionsMGL c.40A §3
No zoning ordinance or by-law shall prohibit, unreasonably restrict or require a special permit or other discretionary zoning approval for the use of land or structures for a single accessory dwelling unit, or the rental thereof, in a single-family residential zoning district
Accessory Structures by City in Plymouth County
1 cities in Plymouth County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
All Plymouth County ordinances
See every category we cover for Plymouth County: parking, noise, fences, fires, animals, pools, and more.
Plymouth County Ordinance Hub →