Build an ADU in Lebanon.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Lebanon — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
18 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Lebanon zoning ordinance · source · 2026-07-05
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 (Class 1 = 10,000 / 20/15/20 / 25%).
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 conservative.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 conservative.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 conservative.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 conservative.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 40,000 sf (~0.92 ac)
Class 3 conservative.
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 30 ft
- Max coverage
- 15% lot
- Min lot
- 130,680 sf (~3.00 ac)
Class 3: 3 acres (reducible to 1 ac via HIS).
- Front
- 40 ft
- Side
- 35 ft
- Rear
- 30 ft
- Max coverage
- 10% lot
- Min lot
- 130,680 sf (~3.00 ac)
Class 3: 3 acres.
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- 1% lot
- Min lot
- 435,600 sf (~10.00 ac)
10 acres, coverage 1%.
- Front
- 40 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 50% lot
- Min lot
- 87,120 sf (~2.00 ac)
2 acres; frontage 200.
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 50% lot
- Min lot
- 87,120 sf (~2.00 ac)
2 acres. Abutting residential: 75 ft setback.
- Front
- 40 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 50% lot
- Min lot
- 87,120 sf (~2.00 ac)
2 acres; frontage 200.
- Front
- 40 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 30% lot
- Min lot
- 50,000 sf (~1.15 ac)
Frontage 150.
- Front
- 40 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 30% lot
- Min lot
- 50,000 sf (~1.15 ac)
Frontage 150.
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 3,000 sf (~0.07 ac)
Downtown: 0 front/side, rear 10. No coverage limit.
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 3,000 sf (~0.07 ac)
Downtown: 0 front/side, rear 10. No coverage limit.
- Front
- 40 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 50% lot
- Min lot
- 75,000 sf (~1.72 ac)
Frontage 200.
- Front
- 20 ft
- Side
- 15 ft
- Rear
- 20 ft
- Max coverage
- 40% lot
- Min lot
- 30,000 sf (~0.69 ac)
Frontage 100.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Lebanon 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 Lebanon (Grafton County). A detached ADU can be up to 950 sf.
In Lebanon's R-2 zone, ADUs follow the single-family setbacks: 25 ft front, 25 ft side, and 30 ft rear. Lebanon has 18 zoning districts in total — see the full table below. Confirm your exact zone with the town.