Build an ADU in Newmarket.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Newmarket — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
13 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Newmarket zoning ordinance · source · 2026-07-05
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
2 acres. 0.5 units/ac.
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 5,000 sf (~0.11 ac)
Road setback res 20 / comm-mixed 30 (conservative 30). 12 units/ac.
- Front
- 30 ft
- Side
- 0 ft
- Rear
- 0 ft
- Max coverage
- —
- Min lot
- 3,000 sf (~0.07 ac)
Res 20 / comm 30. 8 units/ac.
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 5,000 sf (~0.11 ac)
Res 20 / comm 30. 16 units/ac.
- Front
- 15 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 10,890 sf (~0.25 ac)
Road setback 10/15 (conservative 15).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 10,890 sf (~0.25 ac)
Road setback 20/50 (conservative 50).
- Front
- 20 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
1 acre.
- Front
- 15 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
- Front
- 25 ft
- Side
- 30 ft
- Rear
- 30 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
1 acre.
- Front
- 75 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
+75 ft to residential boundaries. 2 acres.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
2 units/ac.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
2 units/ac.
- Front
- 5 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 10,890 sf (~0.25 ac)
4 units/ac.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Newmarket 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 Newmarket (Rockingham County). A detached ADU can be up to 950 sf.
In Newmarket's R-1 zone, ADUs follow the single-family setbacks: 40 ft front, 25 ft side, and 25 ft rear. Newmarket has 13 zoning districts in total — see the full table below. Confirm your exact zone with the town.