Build an ADU in Campton.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Campton — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
9 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Campton zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Principal residential district: 'all remaining land in the Town of Campton' (3.08) — the vast majority of town outside the Rt 3/49/175 commercial corridors. FRONT SETBACK IS MEASURED FROM THE LIMIT (edge) OF THE ROAD OR PRIVATE RIGHT-OF-WAY, not the centerline: all buildings…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Consists of the existing Campton Village and Waterville Estates Village Districts, except portions in the Commercial Zone (3.01). Sec 4.02.A adds permitted uses only (churches, schools, libraries, fire houses, government offices; lodges/restaurants/medical-dental offices by…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 75% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Corridor zone: all land within 500 ft of the CENTERLINE of Rt 3, NH Rt 49, Old Depot Rd, NH Rt 175 (from Winterbrook Rd north), Vintinner Rd and part of Bog Rd (3.02) — the 500-ft dimension defines the ZONE BOUNDARY, not a setback.
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 75% impervious
- Min lot
- 43,560 sf (~1.00 ac)
OVERLAY on parts of the Commercial Zone (Rt 175 north of Mad River Rd, Mad River Rd, Rt 175 between Rt 49 and Winterbrook Rd, Rt 49) excluding the Rt 3 corridor (3.03); where regulations differ, the more stringent applies.
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Protective corridor covering the 100-year floodplains of the Mad, Pemigewasset and Beebe Rivers plus all land within 500 ft of their ordinary high water mark (OHWM), with listed exclusions along Rt 3/175/49 (3.04).
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Northwesterly mountain section of town including part of the White Mountain National Forest (3.05). MIN LOT 3 ACRES (130,680 sf) PER DWELLING UNIT, and slopes over 20% and wetlands may NOT be counted toward the 3 acres (4.02.E.3).
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- —
Four specific parcels near I-93 (tax parcels 15/2/9, 15/2/8, 15/2/7, 15/2/53) (3.06). Setbacks are the town-wide 4.01.12 values (50 ft road/ROW, 25 ft other boundaries); height 35 ft, though nonresidential agricultural/commercial/industrial buildings may exceed 35 ft by…
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- —
Mixed resort/residential/commercial zone on specified lots along Owl Street and north of Rt 49 (3.07). SETBACKS ARE REDUCED from the town-wide standard: buildings min 25 ft from the limit of any existing/proposed road or private ROW and min 15 ft from ANY property boundary…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
FEMA OVERLAY, not a standalone use district: overlays and supplements the other districts on all FEMA special flood hazard areas per the Grafton County Flood Insurance Study and FIRM panels dated 2-8-2024 (4.02.I, amended March 2023); the stricter provision controls.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Campton 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 Campton (Grafton County). A detached ADU can be up to 950 sf.
In Campton's RR zone, ADUs follow the single-family setbacks: 50 ft front, 25 ft side, and 25 ft rear. Campton has 9 zoning districts in total — see the full table below. Confirm your exact zone with the town.