Fall River, MA Accessory Structures: ADU Rules (2026)
ADU rules in Fall River, MA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- State Law
- Ch. 358 Acts of 2024: by right
- Max Size
- 900 sq ft or 50% of principal dwelling
- Effective Date
- February 2, 2025
- Owner Occupancy
- Cannot be required by municipality
Summary
Under Massachusetts law (Ch. 358 of Acts of 2024, effective Feb 2025), ADUs under 900 sq ft are allowed by right on single-family lots statewide. Fall River Mayor Coogan raised concerns about the law but it applies regardless. ADUs must have a separate entrance and cannot exceed half the principal dwelling's floor area or 900 sq ft.
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; provided, that the use of land or structures for such accessory dwelling unit under this paragraph may be subject to reasonable regulations, including, but not limited to, 310 CMR 15.000 et seq., if applicable, site plan review, regulations concerning dimensional setbacks and the bulk and height of structures and may be subject to restrictions and prohibitions on short-term rental, as defined in section 1 of chapter 64G.
Official source re-checked September 8, 2026: the cited page had not changed since it was quoted.
Full Breakdown
The statewide ADU law amends MGL Ch. 40A to allow accessory dwelling units by right in single-family zoning districts. ADUs must be under 900 sq ft or half the principal dwelling's gross floor area, whichever is smaller, and maintain a separate entrance. Municipalities cannot impose owner-occupancy requirements or unreasonably restrict ADU creation. Fall River's Zoning Board has been handling ADU-related decisions, and the city adopted Ordinance No. 2025-12 addressing local implementation.
Violations & Fines
Municipalities cannot deny conforming ADU applications. Unpermitted ADU: standard building code enforcement under 780 CMR.
Frequently Asked Questions
Can I build an ADU on my property in Fall River?
What are the size limits for an accessory dwelling unit in Fall River?
Sources & Official References
- [1]Source
Other rules in Fall River
How Fall River compares: Easiest Cities to Build an ADU·Compare Fall River to another location·View the Massachusetts accessory structures overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.
ADU Rules in Nearby Cities
How other cities in Bristol County handle adu rules.