Build an ADU in Croydon.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Croydon — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
3 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Croydon zoning ordinance · source · 2026-07-07
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- 152,460 sf (~3.50 ac)
Primary residential district: comprises 'all land not included in Village or Conservation District' (Art V.B), 'mainly districts of farms, residences and woodlands.' Permitted uses include single-family or two-family owner-occupied dwellings, home occupations, agriculture,…
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Village centers (Croydon East Village, Croydon Flat) — 'mainly districts of residences, commercial establishments, community buildings and neighborhood businesses' (Art V.C). Permitted uses include any use permitted in C/RR, neighborhood stores, neighborhood service…
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- —
Conservation/open-space district covering specific parcels only: all land within Corbin Park, the YMCA property, and the wetland within Lyme Timber Company land adjacent to Old Route 10 (Art V.A).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Croydon 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 Croydon (Sullivan County). A detached ADU can be up to 950 sf.
In Croydon's RR zone, ADUs follow the single-family setbacks: 35 ft front, 35 ft side, and 35 ft rear. Croydon has 3 zoning districts in total — see the full table below. Confirm your exact zone with the town.