Accessory Structures in Southborough, MA (2026)
2 verified accessory structures rules for Southborough, Massachusetts, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Southborough allows an accessory dwelling unit by right in the Residence A district when it is no larger in gross floor area than half the principal dwelling or 900 square feet, whichever is smaller. A larger unit needs a special permit from the Board of Appeals after Board of Health and Planning Board review. Chapter 174 bars placing a unit in a travel trailer.
Southborough Accessory Dwelling Unit Rules
Some RestrictionsSouthborough Code § 174-2; § 174-8.2(A)(11), (B)(1); § 174-8.3(A); § 174-9(B)
ACCESSORY DWELLING UNIT A self-contained housing unit, inclusive of sleeping, cooking, and sanitary facilities on the same lot as a principal dwelling. ... Accessory dwelling units shall not be located in a travel trailer. ... (11) Accessory dwelling unit that is not larger in gross floor area than ½ the gross floor area of the principal dwelling or 900 sq. ft., whichever is smaller. ... (1) ...
Shed & Carport Rules
In Southborough, a shed is a structure under Chapter 174, and an accessory building in Residence A must sit 10 feet from the rear and side lot lines and stay within 17 feet and one story. A permit is required before any structure is erected. Only very small items escape the yard rules.
Southborough Shed and Accessory Building Rules
Some RestrictionsSouthborough Code § 174-2; § 174-8.2(D)(3)(b)-(c), (D)(4)
ACCESSORY BUILDING OR USE A building, structure or use customarily incidental and subordinate to the principal permitted use of the building or land, located on the same lot as the principal permitted building or use, and not prohibited by this chapter. ... STRUCTURE A man-made combination of materials assembled in a fixed location to give support or shelter or for any other purpose, including ...