Tiny home on wheelsNo statewide tiny-home-on-wheels law; wheeled units as a primary residence are uncommon given the state's density and zoning enforcement.
ADU / accessory unitThis confirms and sharpens an earlier hedged draft. The Affordable Homes Act (Chapter 150 of the Acts of 2024, signed Aug. 6, 2024) amended the state Zoning Act (M.G.L. c. 40A, §§7-8) to require all 350 Massachusetts cities and towns — with one significant exception — to allow one ADU by right, up to 900 sq ft or 50% of the primary home's floor area (whichever is smaller), with no owner-occupancy requirement. Implementing regulations (760 CMR 71.00) took effect Feb. 2, 2025. Over 1,200 ADUs were permitted in the first year.
Minimum square footageState law sets a maximum, not a minimum: 900 sq ft or 50% of the primary home, whichever is smaller
Foundation requirementFoundation-built ADUs have a strong, confirmed statewide legal path anywhere except Boston