Build an ADU in Chesterfield.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Chesterfield — 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 Chesterfield zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 10% building
- Min lot
- 87,120 sf (~2.00 ac)
Principal single-family residential district; first permitted use is single-family detached dwellings (203.2). Min lot area 2 acres = 87,120 sf (4 acres for a two-family dwelling); frontage >=200 ft (300 ft for two-family) (203.4.A-B).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 10% building
- Min lot
- 217,800 sf (~5.00 ac)
Rural/agricultural district; single-family detached dwellings permitted (204.2.A). Min lot area 5 acres = 217,800 sf; frontage >=400 ft (204.4.A-B). Coverage tiered identically to the R district (204.4.C): building <=10% (recorded), total impermeable incl building <=20%,…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 10% building
- Min lot
- 87,120 sf (~2.00 ac)
Village District covering West Chesterfield and Spofford Villages; permits single-family and two-family detached dwellings and multi-family (per Sec 403) (205.2). Min lot area 2 acres = 87,120 sf; frontage >=200 ft (300 ft for two-family) (205.4.A-B).
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- 50% building
- Min lot
- 87,120 sf (~2.00 ac)
Commercial/Industrial District along NH Route 9. Min lot area 2 acres = 87,120 sf; frontage >=200 ft (206.4.A-B). Dwelling units allowed only by special exception within permitted commercial buildings (<=50% of floor area, density <=1 unit/2 acres) (206.3.C).
- Front
- 75 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- 20% building
- Min lot
- 87,120 sf (~2.00 ac)
Office, Retail and Services District (adopted by Town Meeting March 14, 1989) at specific locations along NH Route 9. Lot size 2 acres MIN (=87,120 sf) to 5 acres MAX; frontage >=200 ft (208.4.A-B). Dwelling units allowed only by special exception within permitted buildings…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Chesterfield 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 Chesterfield (Cheshire County). A detached ADU can be up to 950 sf.
In Chesterfield's R zone, ADUs follow the single-family setbacks: 50 ft front, 20 ft side, and 20 ft rear. Chesterfield has 5 zoning districts in total — see the full table below. Confirm your exact zone with the town.