ADU Design & Build
An attached or interior ADU adds a complete small home, with its own kitchen, bath and entrance, to the house you already have.
Learn more about design & build →ADUs in Wilmington, MA
Wilmington has Wilmington and North Wilmington stations. Under state ADU rules, a town cannot require any parking for an ADU within half a mile of a commuter rail, subway, ferry or bus station. Tell us about your lot and an independent designer or builder who works in Wilmington can reach out with a quote.
Building an ADU in Wilmington
Since February 2, 2025, a protected ADU is allowed by right on single-family lots in Wilmington, subject to reasonable local rules such as setbacks and site plan review.
The median home in Wilmington was built around 1979, and about 29% of homes date from before 1960.
Local sources: Mass.gov: Accessory dwelling units
ADU options in Wilmington
Garage Conversion ADU
A garage already has a foundation, walls and a roof, which can make it a practical start for an ADU.
Learn more about garage conversions →
Basement ADU
Many North Shore homes have a full basement that could become an ADU.
Learn more about basement adus →Detached ADU (Backyard Cottage)
A detached ADU is a separate small home in your yard.
Learn more about detached adus →Why the 2025 ADU law matters
Since February 2025, Massachusetts allows one ADU per lot by right in single-family zoning, up to the smaller of 900 sq ft or half the main house. Towns can still apply reasonable local rules.
Sources: Mass.gov: Accessory dwelling units (ADUs) · 760 CMR 71.00: Protected use accessory dwelling units · MassDEP: Guidance on Title 5 compliance for accessory dwelling units (PDF)
8,077housing units
~1979median year built
29%built before 1960
88%owner-occupied
Source: U.S. Census Bureau, ACS 2020–2024 5-year estimates, via Census Reporter.