An Act relative to accessory dwelling units

HD 3172 removes restrictions that prevent homeowners in single-family neighborhoods from creating or renting out accessory dwelling units (ADUs), like backyard cottages or converted garages. It prohibits local zoning rules from blocking ADUs but allows reasonable limits on size, height, setbacks, and short-term rentals. Homeowners near transit (within 0.5 miles of train/subway/bus stations) do not need extra parking for an ADU, and towns may require owner occupancy for the main or accessory unit. For multiple ADUs in a single-family zone, a special permit is still required.