Somerville ADU Bylaw Analysis
UPDATEDProvision-by-provision analysis of Somerville's ADU bylaw against Massachusetts Chapter 150 and 760 CMR 71.00.
Somerville Bylaw Consistency
Somerville Zoning Ordinance (Ord. 2025-16, adopted 06/26/2025) · Last updated June 2025
Last reviewed: February 15, 2026
What This Means
Somerville is relatively ADU-friendly after adopting Ord. 2025-16. The ‘Backyard Cottage’ building type makes detached ADUs straightforward. The main watch item is the affordability requirement in Neighborhood Residential zones — it adds compliance costs that may discourage some projects.
Permit Activity
24 of 40 approved (60%)Share of 2025 applications approved in 2025
Data Provenance
Reviewed: February 15, 2026
AG action: None
Bylaw source: Zoning Ordinance · retrieved February 19, 2026
Version date not published; analysis based on publicly available text retrieved February 19, 2026
8 provisions analyzed against Chapter 150
Full Compliance Analysis Available
We've mapped 8 provisions in Somerville's ADU bylaw against Massachusetts Chapter 150. Enter your details to get the full provision-by-provision analysis.