Build an ADU in Sanbornton.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Sanbornton — 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 Sanbornton zoning ordinance · source · 2026-07-06
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
PRIMARY single-family residential district (Art 6): 'mainly a District of farms and dwellings.' Minimum land area 2 acres (87,120 sf); no dwelling/building on less than 2 acres. Minimum lot frontage 200 ft Setback: 30 ft from any right-of-way line; at least 10 ft from side…
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Rural farms-and-dwellings district (Art 5); largest-area base zone. Minimum land area 3 acres (130,680 sf). Minimum lot frontage 220 ft Set-back 30 ft from any right-of-way line (Art 5.A(6)); side and rear no nearer than 10 ft to the property line (Art 5.A(7)).
- Front
- 35 ft
- Side
- 35 ft
- Rear
- 35 ft
- Max coverage
- —
- Min lot
- 261,360 sf (~6.00 ac)
Large tracts of forest and open land (Art 7). Minimum land area 6 acres (261,360 sf). Minimum lot frontage 600 ft Set-back 35 ft from any right-of-way line (Art 7.A(6)); side and rear no nearer than 35 ft to any property line (Art 7.A(7)).
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 65,340 sf (~1.50 ac)
Seasonal dwellings and recreational/seasonal-use establishments (Art 8). Minimum land area 1.5 acres (65,340 sf). Minimum lot frontage 175 ft Set-back 30 ft from any right-of-way line (Art 8.A(6)); no building within 10 ft of side and rear property lines (Art 8.A(5)).
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 65,340 sf (~1.50 ac)
Historical Preservation District (Art 9), Village Historical Area sub-area = lots fronting on presently maintained town or state roads (Art 9.C(1)). Minimum land area 1.5 acres (65,340 sf); minimum frontage 175 ft (Art 9.D(1)).
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Historical Preservation District (Art 9), Rural Historical Area sub-area = balance of the district not fronting maintained town/state roads (Art 9.C(2)). Minimum land area 3 acres (130,680 sf); minimum frontage 220 ft (Art 9.D(2)).
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- 60% lot
- Min lot
- 21,780 sf (~0.50 ac)
Commercial District (Art 10). Minimum lot size 0.5 acre (21,780 sf) 'but may be required to be larger depending on use, soil suitability and slope' (Art 10.B) — the Art 2 table notes '1/2 (subject to soil conditions)'.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Sanbornton 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 Sanbornton (Belknap County). A detached ADU can be up to 950 sf.
In Sanbornton's GR zone, ADUs follow the single-family setbacks: 30 ft front, 10 ft side, and 10 ft rear. Sanbornton has 7 zoning districts in total — see the full table below. Confirm your exact zone with the town.