Accessory Structures in Maine (2026)

4 rules on the books across Maine, 1 city or county. Select a rule to read the full details.

Severity: Few Restrictions · Light Restrictions · Some Restrictions · Significant Restrictions · Heavy Restrictions

ADU Rules

Rules for building accessory dwelling units (granny flats, in-law suites) including size limits, parking requirements, and owner-occupancy rules.

Per 30-A MRS § 4364-A, enacted by LD 2003 (PL 2021 ch. 672), every Maine municipality SHALL allow at least one…

Portland's Land Use Code lets homeowners build up to two accessory dwelling units per qualifying property, by right, on…

When a storage shed or carport needs a permit, the square-footage exemption thresholds, and the setback and height limits that apply either way.

A small shed or detached accessory structure of 250 square feet or less can sit as close as 5 feet to the rear lot line…

Zoning rules for tiny houses on wheels and foundations, including minimum square footage requirements and where they can be placed.

Maine adopted Appendix Q of the International Residential Code through MUBEC, providing statewide construction…