2026-09-10 · Massachusetts · Compliance

What happened. Massachusetts made a single accessory dwelling unit a by-right use in single-family residential zoning districts, effective 2 February 2025 — and the question every association board has been asked since is whether that overrides the association's own restriction.

It does not. That is the state's own published position, and it is what the text supports.¹

What the law does

Sections 7 and 8 of Chapter 150 of the Acts of 2024 amended G.L. c. 40A §1A (the definition) and §3 (the by-right use). Section 143 of the act delayed section 8 by 180 days, which is where the 2 February 2025 date comes from.²

• No zoning ordinance or by-law may “prohibit, unreasonably restrict or require a special permit or other discretionary zoning approval” for a single ADU, or its rental, in a single-family residential district
• An ADU is no larger than half the gross floor area of the principal dwelling or 900 square feet, whichever is smaller
• No owner-occupancy may be required of either the ADU or the principal dwelling
• Parking: not more than one additional space, and none at all within half a mile of a commuter rail station, subway station, ferry terminal or bus station
• A second ADU still requires a special permit
• Site plan review, dimensional setbacks, bulk and height rules, and Title 5 still apply

Where it stops

Neither section 8 nor the implementing regulation, 760 CMR 71.00, mentions covenants, deed restrictions, condominiums or homeowners associations. 760 CMR 71.03 constrains municipal regulation only.³

The Commonwealth's own ADU guidance says so directly: the ADU law does not address homeowners associations, an HOA may allow or restrict ADU development under its own rules, and condominiums are governed by c. 183A, which the ADU law does not amend.

1. Commonwealth of Massachusetts, Accessory Dwelling Unit (ADU) FAQs ↩
2. Chapter 150 of the Acts of 2024, sections 7, 8 and 143 (session law text) ↩
3. 760 CMR 71.03, Regulation of Protected Use ADUs (full section text) ↩
4. Attorney General Municipal Law Unit decision 11904, Town of Hull, 17 October 2025 ↩