Tiny home on wheelsNo dedicated statewide tiny-home-on-wheels law. This confirms and sharpens an earlier hedged draft: Maine's ADU mandate is real and codified. LD 2003 (2022, now Title 30-A §4364-B) requires every municipality to allow at least one ADU on any lot with a single-family home, with no owner-occupancy requirement. A 2025 follow-up law, LD 1829, requires municipalities to allow up to three housing units on most residential lots (four in designated growth areas with water and sewer) and removed a fire-sprinkler requirement for smaller ADUs.
ADU / accessory unitState policy is now confirmed as one of the stronger statewide positions in the Northeast, on par with Vermont. City-council-government municipalities had to comply with LD 1829 by July 1, 2026; town-meeting-government municipalities have until July 1, 2027.
Minimum square footageNo statewide minimum; municipalities can set lot-size minimums (raised in 2026 amendments to 10,000 sq ft in some non-growth areas)
Foundation requirementFoundation-built ADUs have the clearest, best-documented path; coastal and seasonal towns may add their own conditions