Maine Lot Coverage Limits Law: Statewide Building Setbacks & Zoning Rules (2026)

Key Facts

Coverage cap: 20 percent of lot
Authority: DEP Chapter 1000
Buffer: 75 feet vegetated shoreline
Counts: Buildings, drives, patios
Daily penalty: Up to $25,000

Full Breakdown

Under DEP Chapter 1000 and 38 M.R.S. §§ 435-449-A, lots within the shoreland zone are limited to 20 percent total non-vegetated surface coverage, including buildings, decks, driveways, patios, and other impervious or compacted surfaces. The limit is intended to protect water quality by minimizing stormwater runoff and preserving native vegetation buffers. A 75-foot vegetated buffer along the shoreline is also required. Municipalities must adopt this 20-percent cap; if a town's ordinance is less protective, DEP can override and apply the state default. Outside the shoreland zone, lot coverage is determined by local zoning and is not preempted.

Violations & Penalties

Civil penalties from $100 to $25,000 per day under 38 M.R.S. § 349, removal of excess coverage, and required revegetation supervised by DEP.

Frequently Asked Questions

How much of a Maine shoreland lot can I cover with buildings and pavement?

No more than 20 percent of the lot area within the shoreland zone may be non-vegetated surface, including all structures, decks, driveways, and patios under DEP Chapter 1000.

Does the Maine 20-percent coverage rule apply to lots far from water?

No. The cap applies only within the shoreland zone, generally 250 feet from great ponds, rivers, and tidal waters, or 75 feet from certain streams. Inland lots follow local zoning.

Maine Shoreland Lot Coverage Limit by Statute