Build an ADU in Peterborough.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Peterborough — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
11 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Peterborough zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Principal single-family residential district (single-family and two-family dwellings; ADU permitted per 245-24.1). RECORDED VALUES ARE THE CONSERVATIVE NO-TOWN-WATER TIER: per townwide 245-22.B, any lot not serviced by town water is governed by the Rural District minimum lot…
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- 25% building
- Min lot
- 130,680 sf (~3.00 ac)
Allows any Family District use plus multifamily. RECORDED SETBACKS/LOT ARE THE CONSERVATIVE NO-TOWN-WATER TIER per 245-22.B (Rural District standards: 3 ac; frontage 200 ft; front 50, side/rear 30). District's own standards for lots serviced by town water (245-7.C):…
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Allows any Family District use (so single-family + ADU) plus commercial agriculture, forestry, etc. Minimum dimensional requirements (245-8.D): lot size 3 acres (130,680 sf); setbacks front 50 ft, side and rear 30 ft; frontage on ROW 200 ft No lot-coverage percentage stated.
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- 80% impervious
- Min lot
- —
Mixed-use district; residential (incl single-family) is a permitted use. NO minimum lot sizes, setbacks, or frontages required — the Planning Board sets appropriate setbacks/buffering during Site Plan Review (245-9.C.1).
- Front
- —
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 80% impervious
- Min lot
- —
Mixed-use village district; single-family, two-family, and multifamily residential permitted. No minimum lot sizes or frontages; lot must front on an approved street (245-9.1.C.1). Max 80% impervious cover per lot, multi-lot proposals treated as one lot (245-9.1.C.3).
- Front
- 75 ft
- Side
- 75 ft
- Rear
- 75 ft
- Max coverage
- 80% impervious
- Min lot
- 1,089,000 sf (~25.00 ac)
Hospital-campus district (hospitals, clinics, multifamily, elderly housing, nursing homes, etc. Min TRACT size 25 acres (1,089,000 sf) contiguous in single/consolidated ownership (245-9.2.F.1) — recorded as minLotSqft.
- Front
- 5 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- —
Pedestrian-oriented mixed-use core; residential uses permitted outright. Lot size: no minimum; frontage: no minimum (245-10.D.1-2). Performance standards (DC column): 'There is no maximum building coverage, except that the site must be designed to dispose of all runoff and…
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 80% impervious
- Min lot
- —
Highway-node commercial district; residential only if incidental to a principal business use (max 30% of floor area, no storefront space). Lot size: no minimum; frontage 50 ft (245-10.1.D.1-2). No lot shall have more than 80% impervious coverage; all new development must…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 80% impervious
- Min lot
- —
Highway-corridor commercial/industrial district; residential only if associated with a principal business use. Lot size: no minimum; frontage 50 ft (245-10.2.D.1-2). No lot shall have more than 80% impervious coverage; new development must connect to Town water & sewer…
- Front
- 25 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 20,000 sf (~0.46 ac)
Employment/industrial park district; no residential dwellings among permitted uses. Space and bulk (245-11.D): minimum lot area 20,000 sf; minimum BUILDING AND PARKING LOT setbacks front 25 ft, side and rear 20 ft — except not less than 100 ft when abutting a residential…
- Front
- 100 ft
- Side
- 100 ft
- Rear
- 100 ft
- Max coverage
- 25% building
- Min lot
- 2,178,000 sf (~50.00 ac)
Age-55+ community district (single-family, two-family, multifamily, congregate care, nursing homes). Minimum TRACT size 50 acres (2,178,000 sf) contiguous in single/consolidated ownership — recorded as minLotSqft (245-11.2.E.1).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Peterborough 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 Peterborough (Hillsborough County). A detached ADU can be up to 950 sf.
In Peterborough's Family zone, ADUs follow the single-family setbacks: 50 ft front, 30 ft side, and 30 ft rear. Peterborough has 11 zoning districts in total — see the full table below. Confirm your exact zone with the town.