Build an ADU in Walpole.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Walpole — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
6 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Walpole zoning ordinance · source · 2026-07-07
- Front
- 65 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 40,000 sf (~0.92 ac)
Principal single-family residential district (single-family and two-family dwellings permitted; Appendix B). Lot area not less than 40,000 sf with frontage not less than 200 ft (Art V.D.1.a). FRONT setback is measured from the CENTER LINE of the abutting right-of-way: no…
- Front
- 65 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 25,000 sf (~0.57 ac)
Smaller-lot residential district (single-family, two-family, and by special exception/permitted multi-family per Appendix B). Lot area not less than 25,000 sf with frontage not less than 150 ft (Art V.D.1.b).
- Front
- 65 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 25,000 sf (~0.57 ac)
Lot area not less than 25,000 sf with minimum frontage of 150 ft (Art VI.D.1).
- Front
- 85 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 25,000 sf (~0.57 ac)
Industrial establishments must be located at least 85 ft from the CENTER LINE of any right-of-way and not less than 20 ft from each side or rear boundary (Art VII.C.1) - front distance is measured from centerline, and is larger (85 ft) than other districts.
- Front
- 65 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 40,000 sf (~0.92 ac)
Largest district in Walpole; comprises all lands not allotted to the North Walpole Village precinct, Residential, Commercial, Industrial or Timberland districts (Art VIII.E). Lot area not less than 40,000 sf FOR EACH DWELLING UNIT with minimum frontage of 200 ft (Art VIII.D.1).
- Front
- 65 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 40,000 sf (~0.92 ac)
Forestry-preservation district; any use permitted in the Rural/Agricultural District is permitted, and a building may be constructed only with a permit from the Selectboard/Planning Board (Art IX.B). Lot area not less than 40,000 sf FOR EACH DWELLING UNIT with minimum…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Walpole 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 Walpole (Cheshire County). A detached ADU can be up to 950 sf.
In Walpole's R-A zone, ADUs follow the single-family setbacks: 65 ft front, 20 ft side, and 20 ft rear. Walpole has 6 zoning districts in total — see the full table below. Confirm your exact zone with the town.