ADU Structure Type Restrictions
AG DisapprovedSouthborough, Worcester County
Building & SafetyWhat This Means for Your Project
The Attorney General has disapproved this provision as inconsistent with G.L. c. 40A §3. It is preempted by state law, though it may still appear in Southborough's local code. Builders should cite the AG decision if this comes up during permitting.
State Law
760 CMR 71.03(3)(b)(7) provides that any requirement prohibiting a Modular Dwelling Unit from being used as a Protected Use ADU that is more restrictive than Building Code is unreasonable.
Local Bylaw
ADUs shall not be located in a travel trailer or mobile home.
Impact on Your Project
The town’s definition of “mobile home” was broad enough to include manufactured homes that qualify as Modular Dwelling Units under state regulations. The AG struck the words “or mobile home” from the bylaw — the travel trailer ban remains.
AG Decision
AG partial disapproval February 17, 2026 (AAG Nicole B. Caprioli): Disapproved ban on mobile homes as ADUs because town definition encompasses protected Modular Dwelling Units.
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