Build an ADU in Pittsfield.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Pittsfield — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
5 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Pittsfield zoning ordinance · source · 2026-07-07
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 65,340 sf (~1.50 ac)
The town's principal moderate-density single-family residential district (purpose: 'principally residential neighborhoods for SINGLE-FAMILY DWELLINGS', Art 3 Sec 1(b)(2)); single-family by right, two-family/multi-family prohibited.
- Front
- 10 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 10,890 sf (~0.25 ac)
High-density residential district around the village core; single-family dwellings permitted by right. Min lot 1/4 acre (10,890 sf); min frontage 50 ft; max height 35 ft; max 3 stories. Front = 'STREET SETBACK', measured from the STREET boundary (right-of-way line, not…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Low-density rural district; single-family dwellings by right. Min lot 2 acres (87,120 sf); min frontage 225 ft; street (front) setback 50 ft, side/rear 25 ft; max height 35 ft; max 3 stories; no coverage percentage - max FLOOR AREA RATIO 0.1 instead.
- Front
- 10 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 10,890 sf (~0.25 ac)
Downtown commercial core; since the 2019 amendment single-family dwellings are permitted by right here too. Min lot 1/4 acre (10,890 sf); min frontage 50 ft; setbacks 10/10/10; max height 35 ft; max 3 stories; no coverage percentage - max FLOOR AREA RATIO 0.7 instead.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Accommodates existing industrial and complementary commercial uses; single-family dwellings permitted by right (2019 amendment). Min lot 1 acre (43,560 sf); min frontage 150 ft; setbacks 25/25/25; max height 35 ft; max 3 stories; no coverage percentage - max FLOOR AREA RATIO…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Pittsfield 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 Pittsfield (Merrimack County). A detached ADU can be up to 950 sf.
In Pittsfield's Suburban zone, ADUs follow the single-family setbacks: 25 ft front, 25 ft side, and 25 ft rear. Pittsfield has 5 zoning districts in total — see the full table below. Confirm your exact zone with the town.