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 Lynnfield, MA
Under state ADU rules, Lynnfield can require at most one parking space for a protected ADU, and none if the lot is within half a mile of a transit station. Tell us about your lot and an independent designer or builder who works in Lynnfield can reach out with a quote.
Building an ADU in Lynnfield
Since February 2, 2025, a protected ADU is allowed by right on single-family lots in Lynnfield, subject to reasonable local rules such as setbacks and site plan review.
The median home in Lynnfield was built around 1964, and about 43% of homes date from before 1960.
Local sources: Mass.gov: Accessory dwelling units
ADU options in Lynnfield
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)
4,597housing units
~1964median year built
43%built before 1960
87%owner-occupied
Source: U.S. Census Bureau, ACS 2020–2024 5-year estimates, via Census Reporter.