Maine state law: detached sheds under 200 sq ft exempt from building permit under MUBEC and IRC § R105.2

Shed and detached accessory-structure regulation is delegated to municipalities under 30-A § 4352 (Zoning ordinances) and 30-A § 3001 (Home Rule), with the Maine Uniform Building and Energy Code under 25 MRS § 2451 providing the statewide building-code overlay. MUBEC incorporates the 2015 International Residential Code (with Maine amendments). Per IRC Section R105.2 (Work exempt from permit), 'one-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 200 square feet (18.58 m²)' are exempt from the building-permit requirement. Sheds OVER 200 sq ft, sheds with plumbing or electrical service, sheds with permanent foundations, and sheds proposed within the mandatory Shoreland Zone (38 MRS § 435 et seq., within 250 ft of great ponds, rivers, freshwater wetlands, and tidal waters) or within mapped Special Flood Hazard Areas require a building permit from the local CEO. Zoning setbacks (typically 5-10 feet from rear and side property lines, no shed in the front yard) and maximum height (typically 12-15 feet) are set by individual municipal zoning code under 30-A § 4352. The MUBEC permit exemption for sheds ≤200 sq ft does NOT exempt the owner from zoning compliance — a small shed must still meet the local setback rule, and shoreland setbacks (75 feet from the normal high-water line) apply regardless of size within the Shoreland Zone.

A shed built in violation of local zoning setbacks or built in the Shoreland Zone without required permits is a violation enforceable by the local CEO under 30-A MRS § 4452, with civil penalties typically $100-$2,500 per day. Shoreland-zone violations carry enhanced penalties under 38 MRS § 349 (up to $25,000 per day).