Build an ADU in Gorham.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Gorham — 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 Gorham zoning ordinance · source · 2026-07-07
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 10,000 sf (~0.23 ac)
Primary single-family residential district; permitted by right is a single-family dwelling or single-family dwelling with accessory dwelling unit, plus one two-family dwelling (duplex) per lot and manufactured housing on individual lots (4.01 A).
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Lower-density residential district; single-family dwelling or single-family dwelling with one accessory dwelling unit permitted by right, plus cluster development (4.02 A). Min lot area not less than one acre = 43,560 sf; min frontage 100 ft (4.02 C.1, C.4).
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 10,000 sf (~0.23 ac)
Mixed commercial/residential downtown-fringe district; residential uses same as Residential A unless otherwise listed; multi-family housing permitted (4.03 A, B). Min lot area 10,000 sf; min frontage 75 ft; multi-family needs +10,000 sf per unit above 3 units (4.03 D.1, D.6,…
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Highway/commercial district allowing light manufacturing, auto/RV sales, contractor equipment yards and multi-family housing (4.04 B); residential uses same as Residential A unless listed. Min lot area not less than 1 acre = 43,560 sf; min frontage 100 ft; multi-family needs…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Heavy and light industrial district (4.05). Min area not less than one acre = 43,560 sf; min frontage 100 ft (4.05 C.1, C.4).
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 217,800 sf (~5.00 ac)
Forestry/agriculture district where soils and terrain are often not appropriate for development (4.06). Min lot area not less than 5 acres = 217,800 sf; min frontage 200 ft (4.06 C.1, C.4).
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Any land owned or maintained by the Town of Gorham set aside for public enjoyment or recreation (4.07). No residential use and no dimensional standards (lot area, setbacks, frontage, coverage) are established for this municipal-recreation district in the ordinance.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Gorham 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 Gorham (Coös County). A detached ADU can be up to 950 sf.
In Gorham's Residential A zone, ADUs follow the single-family setbacks: 20 ft front, 10 ft side, and 20 ft rear. Gorham has 7 zoning districts in total — see the full table below. Confirm your exact zone with the town.