Build an ADU in Lyndeborough.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Lyndeborough — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
5 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Lyndeborough zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 217,800 sf (~5.00 ac)
The town's principal single-family district: RL1 is the catch-all covering all land not in another district (700.01). Single-family dwellings permitted (701.00.a); two-family by conditional use permit (703, min 4 ac / 500 ft frontage).
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Mixed-use town-center district; single-family dwellings, retail, offices, restaurants etc. permitted (501.00); two-family by conditional use permit (503, min 4 ac / 300 ft frontage). Min lot 2 contiguous acres of dry land undivided by wetland, pond or drainage way (502.01);…
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 217,800 sf (~5.00 ac)
Low-density rural district covering all land at/above 1,000 ft but below 1,500 ft elevation (800.01). Single-family dwellings permitted; two-family by conditional use permit (803, min 10 ac / 1,000 ft frontage).
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 435,600 sf (~10.00 ac)
Most restrictive rural district: all land at/above 1,500 ft elevation (900.01), intended to protect remote/sensitive land. Min lot 10 acres with 2 contiguous acres of dry land undivided by wetland, pond or drainage way (902.01); frontage 500 ft (902.02).
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Non-residential district (light manufacturing, offices, warehouses, retail; Table 302.00 marks single-family dwellings N). Min lot 2 contiguous acres of dry land undivided by wetland, pond or drainage way (602.01); frontage 250 ft (602.02).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Lyndeborough 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 Lyndeborough (Hillsborough County). A detached ADU can be up to 950 sf.
In Lyndeborough's RL1 zone, ADUs follow the single-family setbacks: 50 ft front, 50 ft side, and 50 ft rear. Lyndeborough has 5 zoning districts in total — see the full table below. Confirm your exact zone with the town.