Build an ADU in Exeter.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Exeter — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
19 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Exeter zoning ordinance · source · 2026-07-05
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 15% building
- Min lot
- 87,120 sf (~2.00 ac)
No-W&S 2 ac; municipal 40,000. Side 15 one / 30 both.
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 10% building
- Min lot
- 87,120 sf (~2.00 ac)
2 acres all tiers.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 15,000 sf (~0.34 ac)
No-W&S 1 ac; municipal 15,000.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 24,000 sf (~0.55 ac)
12,000/DU.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 12,000 sf (~0.28 ac)
Municipal W&S required.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 12,000 sf (~0.28 ac)
Detached SF tier.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 30% building
- Min lot
- 12,000 sf (~0.28 ac)
3,630/DU. Cov 30% if 3+ stories (conservative).
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 20 ft
- Max coverage
- 30% building
- Min lot
- 8,000 sf (~0.18 ac)
Municipal W&S required. Max 8 units/ac.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 10,000 sf (~0.23 ac)
Municipal W&S required.
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 25 ft
- Max coverage
- 25% building
- Min lot
- 10,000 sf (~0.23 ac)
Municipal W&S required.
- Front
- 10 ft
- Side
- —
- Rear
- 20 ft
- Max coverage
- 75% building
- Min lot
- 5,000 sf (~0.11 ac)
Side conditional (abutting yard or 10 whichever less).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 50 ft
- Max coverage
- 30% building
- Min lot
- 20,000 sf (~0.46 ac)
Rear 20 by special exception.
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 60 ft
- Max coverage
- 40% building
- Min lot
- 40,000 sf (~0.92 ac)
Height 50 ft.
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 50 ft
- Max coverage
- 30% building
- Min lot
- 20,000 sf (~0.46 ac)
Open space 25%.
- Front
- 10 ft
- Side
- —
- Rear
- 25 ft
- Max coverage
- 75% building
- Min lot
- 5,000 sf (~0.11 ac)
Side conditional. 50 ft river side.
- Front
- 75 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- 20% building
- Min lot
- 174,240 sf (~4.00 ac)
4 acres. Municipal W&S not permitted.
- Front
- 75 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 40% building
- Min lot
- 87,120 sf (~2.00 ac)
2 acres.
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 50 ft
- Max coverage
- 40% building
- Min lot
- 40,000 sf (~0.92 ac)
Open space 25%.
- Front
- 75 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 40% building
- Min lot
- 87,120 sf (~2.00 ac)
2 acres. Height 86 ft.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Exeter 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 Exeter (Rockingham County). A detached ADU can be up to 950 sf.
In Exeter's R-1 zone, ADUs follow the single-family setbacks: 25 ft front, 15 ft side, and 25 ft rear. Exeter has 19 zoning districts in total — see the full table below. Confirm your exact zone with the town.