Build an ADU in Hampton.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Hampton — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
12 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Hampton zoning ordinance · source · 2026-07-05
- Front
- 20 ft
- Side
- 15 ft
- Rear
- 10 ft
- Max coverage
- 60% impervious
- Min lot
- 15,000 sf (~0.34 ac)
Impervious 60%.
- Front
- 20 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 60% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Impervious 60%.
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 60% impervious
- Min lot
- 10,000 sf (~0.23 ac)
5,000/DU. Impervious 60%.
- Front
- 10 ft
- Side
- 7 ft
- Rear
- 7 ft
- Max coverage
- 60% impervious
- Min lot
- 6,000 sf (~0.14 ac)
3,000/DU. Impervious 60%.
- Front
- 10 ft
- Side
- 7 ft
- Rear
- 7 ft
- Max coverage
- 75% impervious
- Min lot
- 10,000 sf (~0.23 ac)
Impervious 75%.
- Front
- 4 ft
- Side
- 4 ft
- Rear
- 4 ft
- Max coverage
- 75% impervious
- Min lot
- 5,000 sf (~0.11 ac)
Impervious 75%.
- Front
- 4 ft
- Side
- 4 ft
- Rear
- 4 ft
- Max coverage
- —
- Min lot
- 5,000 sf (~0.11 ac)
Impervious no requirement.
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
All cells blank; governed by Town Center refs.
- Front
- 10 ft
- Side
- 7 ft
- Rear
- 7 ft
- Max coverage
- 60% impervious
- Min lot
- —
500 sf/DU. Impervious 60%.
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 60% impervious
- Min lot
- 22,000 sf (~0.51 ac)
Impervious 60%.
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 400,000 sf (~9.18 ac)
20,000/DU.
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 120,000 sf (~2.75 ac)
1,000/DU.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Hampton 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 Hampton (Rockingham County). A detached ADU can be up to 950 sf.
In Hampton's RA zone, ADUs follow the single-family setbacks: 20 ft front, 15 ft side, and 10 ft rear. Hampton has 12 zoning districts in total — see the full table below. Confirm your exact zone with the town.