Build an ADU in Sunapee.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Sunapee — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
9 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Sunapee zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 50% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Town's principal medium-density single-family residential district; Single-Family Dwellings permitted by right (Sec 4.10, 'Residential District - R'). Min lot 1.0 acre (43,560 sf); max residential density 1 du/1.0 acre.
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 40% impervious
- Min lot
- 65,340 sf (~1.50 ac)
Low-density residential; includes the remainder of Town not otherwise described plus all major islands of Lake Sunapee. Min lot 1.5 acres (65,340 sf); density 1 du/1.5 acre. Front 75 ft on Routes 11/103/103B, 50 ft all other roads (50 ft recorded), measured from centerline.
- Front
- 75 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- 30% impervious
- Min lot
- 130,680 sf (~3.00 ac)
Remote natural area in the NW corner of Town; very low-density residential plus recreation/forestry. Min lot 3.0 acres (130,680 sf); density 1 du/3.0 acre. Front setback 75 ft (75 ft on both Routes 11/103/103B AND all other roads for this district), measured from centerline.
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 40% impervious
- Min lot
- 65,340 sf (~1.50 ac)
Highway-service businesses along Route 11 between Georges Mills and Brown's Hill Road while keeping rural-residential character with larger lots. Min lot 1.5 acres (65,340 sf); density 1 du/1.5 acre. Front 75 ft on Routes 11/103/103B, 50 ft other roads (50 ft recorded), from…
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 50% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Light commercial plus increased residential density along Avery Road / Sargent Road while keeping general residential character. Min lot 1.0 acre (43,560 sf); density 1 du/0.5 acre. Front 75 ft on Routes 11/103/103B, 40 ft other roads (40 ft recorded), from centerline.
- Front
- 40 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 80% impervious
- Min lot
- 21,780 sf (~0.50 ac)
Commercial, light-industrial and tourism uses (Wendell Village and the Route 103 / Brook Road / Cross Road area). Min lot 0.5 acre (21,780 sf); density 1 du/0.5 acre. Front 75 ft on Routes 11/103/103B, 40 ft other roads (40 ft recorded), from centerline.
- Front
- 40 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 60% impervious
- Min lot
- 21,780 sf (~0.50 ac)
Mostly single-family and two-family residential with some low-impact commercial, adjacent to the two Village-Commercial districts (Sunapee Village and Georges Mills). Min lot 0.5 acre (21,780 sf); density 1 du/10,000 sf.
- Front
- 40 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 80% impervious
- Min lot
- 21,780 sf (~0.50 ac)
Sunapee Village center (Harbor / Lower Village); highest-density mix of commercial, public, institutional and single/multi-family uses. Min lot 0.5 acre (21,780 sf); density 1 du/10,000 sf. Front 75 ft on Routes 11/103/103B, 40 ft other roads (40 ft recorded), from centerline.
- Front
- 40 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 65% impervious
- Min lot
- 21,780 sf (~0.50 ac)
Georges Mills village center (600-ft radius around the Route 11 / Springfield Road intersection); New-England-town-center mix of uses (adopted 03/12/2024). Min lot 0.5 acre (21,780 sf); density 1 du/7,000 sf (the highest density in Town).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Sunapee 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 Sunapee (Sullivan County). A detached ADU can be up to 950 sf.
In Sunapee's R zone, ADUs follow the single-family setbacks: 50 ft front, 15 ft side, and 15 ft rear. Sunapee has 9 zoning districts in total — see the full table below. Confirm your exact zone with the town.