ADU Rules: Wellesley vs Weymouth
How do adu rules rules compare between Wellesley, MA and Weymouth, MA?
Wellesley and Weymouth have similar restriction levels.
Wellesley, MA
Norfolk County
Wellesley regulates ADUs under Section 5.13 of the Wellesley Zoning Bylaw. At the April 2025 Annual Town Meeting, Wellesley adopted Article 40.1 to amend its ADU bylaw, and the Massachusetts Attorney General approved the changes effective April 15, 2025. As of April 15, 2025, detached ADUs are permitted by-right in Single Residence Districts; a Special Permit is no longer required, consistent with the state Affordable Homes Act.
View full Wellesley rules →Weymouth, MA
Norfolk County
Weymouth Town Council passed ADU Ordinance Amendment (Measure 24-119) adding Article 29 to Chapter 120. ADUs are allowed by right on single-family lots up to 900 sq ft or 50% GFA. Lots under 5,000 sq ft are ineligible.
View full Weymouth rules →Key Facts Comparison
| Fact | Wellesley | Weymouth |
|---|---|---|
| Local Code | Wellesley Zoning Bylaw §5.13 | - |
| Amendment | Art. 40.1 (April 2025 ATM) | - |
| AG Approval | April 15, 2025 | - |
| Detached ADUs | By-right (no Special Permit) | - |
| Annual Certificate | Required from Planning Dept. | - |
| Code Section | - | Weymouth Code Ch. 120, Art. 29 (Measure 24-119) |
| Max Size (small lots) | - | 750 sq ft (lots under 25,000 sq ft) |
| Max Size (large lots) | - | 900 sq ft (lots over 25,000 sq ft) |
| Ineligible Lots | - | Under 5,000 sq ft |
| Parking | - | 1 space (waived within 0.5 mi of transit) |
Highlighted rows indicate differences between cities.
Wellesley FAQ
Are detached ADUs allowed by-right in Wellesley?
Yes, as of April 15, 2025. The Massachusetts Attorney General approved Wellesley's Article 40.1 bylaw amendment, removing the Special Permit requirement for detached ADUs in Single Residence Districts. A building permit and annual Certificate of Compliance are still required.
How big can a Wellesley ADU be?
Under §5.13 and the MA Affordable Homes Act (G.L. c. 40A as amended), an ADU is capped at 900 sq ft or 50% of the primary dwelling's gross floor area, whichever is smaller.
Does Wellesley require an annual filing for ADUs?
Yes. Wellesley §5.13 requires an annual Certificate of Compliance (Notice of Accessory Unit) from the Planning Department in addition to the initial building permit from the Inspector of Buildings.
Weymouth FAQ
Can I build an ADU on my property in Weymouth?
Weymouth Town Council passed ADU Ordinance Amendment (Measure 24-119) adding Article 29 to Chapter 120. ADUs are allowed by right on single-family lots up to 900 sq ft or 50% GFA. Lots under 5,000 sq ft are ineligible.
What are the size limits for an accessory dwelling unit in Weymouth?
Code Section: Weymouth Code Ch. 120, Art. 29 (Measure 24-119). Max Size (small lots): 750 sq ft (lots under 25,000 sq ft). Max Size (large lots): 900 sq ft (lots over 25,000 sq ft). Ineligible Lots: Under 5,000 sq ft.
Compare other topics
See how Wellesley and Weymouth compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool