Build an ADU in Moultonborough.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Moultonborough — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
4 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Moultonborough zoning ordinance · source · 2026-07-06
- Front
- 25 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 40,000 sf (~0.92 ac)
Primary single-family district; covers the entire town outside the three commercial road corridors (Sec 3.2.1.2). Residential/agricultural setbacks (Sec 3.2.2): front = 25 ft from the edge of the right-of-way, OR 50 ft from the centerline of the improved road surface where…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 50% impervious
- Min lot
- 40,000 sf (~0.92 ac)
Commercial corridor: land within 500 ft of the ROW edge of designated Route 25/109 segments (Sec 6.3.2). Coverage: buildings, inventory, equipment, storage, parking, driveway and any impervious surfaces shall not exceed 50% of the lot (impervious basis, Sec 6.6.3).
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 50% impervious
- Min lot
- 40,000 sf (~0.92 ac)
Commercial corridor: land within 500 ft of the ROW edge of a separate designated Route corridor (Sec 6.3.3). Same standards as Zone A: setbacks front 50 / side 25 / rear 25 ft (Sec 6.6.2); 25 ft front vegetative buffer; coverage cap 50% impervious (Sec 6.6.3); min lot per…
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 65% impervious
- Min lot
- 40,000 sf (~0.92 ac)
The Village / 'Corner' district: land within 500 ft of the centerline of Route 25 from Blake Road to the Route 109 South intersection (Sec 6.3.4), intended to preserve historic village character. Coverage may be increased to a maximum of 65% impervious (Sec 6.6.3).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Moultonborough ADU FAQ
Yes. Under NH RSA 674:71-73 (HB 577), one accessory dwelling unit is allowed by-right on single-family lots statewide, including Moultonborough (Carroll County). A detached ADU can be up to 950 sf.
In Moultonborough's RES-AG zone, ADUs follow the single-family setbacks: 25 ft front, 20 ft side, and 20 ft rear. Moultonborough has 4 zoning districts in total — see the full table below. Confirm your exact zone with the town.