Build an ADU in Swanzey.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Swanzey — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
7 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Swanzey zoning ordinance · source · 2026-07-07
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Primary single-family residential district; permitted use is one-family dwelling (Sec IV.B.1.a). All lots must be at least 1 acre (43,560 sf) with 150 ft frontage on a Town or State maintained road; front setback 30 ft from the front property line, side and rear 20 ft from…
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Lowest-density district. All lots must be at least 3 acres (130,680 sf) with 225 ft frontage on a Town or State maintained road; front setback 30 ft from the front property line, side and rear 20 ft from property lines (Sec IV.A.3).
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
Mixed village district along State Route 32 that permits one-family dwellings plus small business uses. All lots must be at least one-half acre (21,780 sf) with 100 ft frontage on a Town or State maintained road; front setback 30 ft from the front property line, side and rear…
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Commercial district that also permits one-family dwellings established before the district and one-to-two-family conversions. All lots must be at least 1 acre (43,560 sf) with 125 ft frontage on a town or State maintained road (Sec V.B.3).
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
Village mixed-use district in West Swanzey (North Winchester/Main/Ashuelot/Summer Streets). All lots must be at least one-half acre (21,780 sf) with 100 ft frontage on a Town or State maintained road; front setback 30 ft from the front property line, side and rear 20 ft from…
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Industrial/commercial district along Route 10 near the Keene line. Minimum lot size is TIERED by access: lots taking access from Rte 10 must be at least 3 acres (130,680 sf) with 400 ft frontage on Rte 10; lots using a feeder road from Rte 10 need only 1 acre (43,560 sf) with…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 50% building
- Min lot
- 87,120 sf (~2.00 ac)
Industrial-park district (moved from former Sec X-A in 2022) off Rte 32/Page Court. Minimum lot area 2 acres (87,120 sf), minimum width at building line 150 ft, minimum frontage 150 ft (Sec VI.B.8.a-c).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Swanzey 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 Swanzey (Cheshire County). A detached ADU can be up to 950 sf.
In Swanzey's RES zone, ADUs follow the single-family setbacks: 30 ft front, 20 ft side, and 20 ft rear. Swanzey has 7 zoning districts in total — see the full table below. Confirm your exact zone with the town.