Build an ADU in Springfield.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Springfield — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
2 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Springfield zoning ordinance · source · 2026-07-07
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- 65,340 sf (~1.50 ac)
Primary district; permitted uses include one- and two-family dwelling units (sec 3.11.A). SETBACK IS A SINGLE 35 ft STANDARD applied to all sides: 'There shall be a minimum distance of 35 feet between any building and the edge of the right-of-way for any road or public way or…
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 2,178,000 sf (~50.00 ac)
Large-tract forest-preservation district; single-family dwelling and accessory structures are a permitted use (sec 3.21.F). SETBACK IS A SINGLE 50 ft STANDARD applied to all sides: 'a minimum distance of 50 feet between any building and the edge of the right-of-way for any…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Springfield 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 Springfield (Sullivan County). A detached ADU can be up to 950 sf.
In Springfield's RR zone, ADUs follow the single-family setbacks: 35 ft front, 35 ft side, and 35 ft rear. Springfield has 2 zoning districts in total — see the full table below. Confirm your exact zone with the town.