MA S1474

Defines "movable tiny house" as a transportable dwelling unit on a frame or chassis with not more than 400 square feet (excluding lofts, decks, porches), allowed on lots where single-family homes are permitted or as accessory dwelling units

Requires movable tiny houses to comply with state building code standards but allows reduced insulation requirements (R13 walls, R19 floors, R25 ceiling)

Directs MassDOT and Registry of Motor Vehicles to establish a new titling category for movable tiny houses with a $100 registration fee

Allows occupancy for up to 180 days before on-site inspection; after 180 days, requires established address, utilities, wastewater system, and certificate of occupancy inspection

Prohibits municipalities from establishing design criteria that effectively exclude movable tiny houses and authorizes towns to offer tax abatements to incentivize hosted parking of these units