Important note:
As of 2025, Massachusetts’ Affordable Homes Act requires that one ADU under 900 sq. ft. be allowed by right in single-family zoning districts statewide, subject to reasonable local rules on things like setbacks, parking, and septic capacity. (source: Massachusetts Government - ADUs)

Many towns are still updating their zoning to match the new law, so think of this as a starting point, not legal advice. Please reach out to your local Building and Zoning Departments. Information deemed accurate as of 12/2025.

🏡 Athol

• Athol’s existing zoning bylaws predate the new ADU law and don’t have a modern, standalone ADU article yet. (source: athol-ma.gov)

• Practically speaking, the new state ADU rules apply, so a single ADU under 900 sq. ft. is allowed by right in single-family zones, but you’ll still need to meet building code and septic/sewer capacity. (source: Athol Daily News)

• Homeowners: Call the Athol Building/Planning Department early to confirm how they’re currently handling ADU permits while bylaws catch up.

🏡 Templeton

• Templeton already defines an “accessory apartment” as a smaller, subordinate dwelling unit within or attached to a single-family home. (source: eCode360)

• Historically, these have been regulated as attached/within-the-home units; the new state law now also supports one ADU by right in single-family districts, with local dimensional rules still in play.

• Key point: Great option for in-home in-laws or long-term rental, but owners should confirm size limits, parking, and septic expectations with the town.

🏙️ Gardner

• Gardner has been actively updating its ADU policies. A recent DPW policy requires detached ADUs to have their own separate water and sewer connections to city mains. (source: Gardner ADU Policy)

• The city is in the process of adopting a more complete ADU ordinance, including updated size limits (discussions around up to ~1,250 sq. ft.) and zoning alignment with the state law. (source: Citizen Portal)

• Translation: ADUs are welcomed, but utility and infrastructure requirements matter. Detached units will have more cost and design considerations.

🌲 Westminster

• Westminster has an existing Accessory Dwelling Unit bylaw that historically required a special permit, owner occupancy, max size around 700 sq. ft., and at least three off-street parking spaces. (source: westminster-ma.gov)

• With the new state law, at least one ADU must now be allowed by right in single-family districts; the town is acknowledging this in its recent housing planning documents and may further update the bylaw language. (source: westminster-ma.gov)

• What to emphasize: Westminster is ADU-friendly but detailed; design, parking, and septic capacity are closely reviewed.

🌆 Fitchburg

• Fitchburg’s zoning has long allowed accessory apartments in certain districts, typically within the main structure, with a size cap around 800 sq. ft. and historic owner-occupancy expectations. (source: Fitchburg Draft Zoning Amendment)

• Independent ADU trackers note that Fitchburg’s current rules are not yet fully aligned with the new statewide by-right law, so more changes are likely.

• Best guidance: Assume and confirm- one ADU by right is permitted under state law, but check carefully for district limitations and whether detached units are allowed.

🌇 Leominster

• Leominster has been actively working on an ADU update; recent draft amendments state that “the addition of a single accessory dwelling unit is allowed by right” if it complies with Article XV and all zoning, building, and sanitary regs. (source: leominster-ma.gov - ADUs)

• There’s ongoing discussion around setbacks, parking, and which structures qualify, but the direction is clearly toward by-right ADUs consistent with the state law. (source: Citizen Portal - Leominster ADUs)

• Takeaway: Leominster is moving toward a predictable, by-right ADU path, but homeowners still need to design around setbacks and lot layout.

🧱 Clinton

• While Clinton’s full zoning update is still emerging, local resources already highlight that Massachusetts now permits ADUs under 900 sq. ft. by right in single-family zones, and that this applies in Clinton as well. (source: viacadllc.com+1)

• Clinton’s downtown and existing housing stock make attached or internal ADUs especially attractive; detached units will still be subject to dimensional and design controls.

• Message to owners: ADUs are possible, but run plans past the Building and Planning offices before you draw final conclusions.

Because the ADU law is new and local bylaws are evolving, the safest move is to treat this as a starting point and then call your town’s Building or Planning Department for the latest requirements. If you’d like help thinking through where an ADU makes sense on your property, or what buyers will look for when you eventually sell, we’re happy to help.

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