Build an ADU in Bristol.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Bristol — 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 Bristol zoning ordinance · source · 2026-07-07
- Front
- 20 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 55% impervious
- Min lot
- 40,000 sf (~0.92 ac)
The town's residential district — neighborhoods adjacent to the commercial core; Single & Two-Family Dwelling is a permitted use. Min lot (single & two-family) is utility-tiered: Class 1 (town water AND sewer) 10,000 sf; Class 2 (water OR sewer) 25,000 sf; Class 3 (private…
- Front
- 20 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 40% impervious
- Min lot
- 80,000 sf (~1.84 ac)
Low-to-medium-density rural living district covering most outlying land; Single & Two-Family Dwelling, Manufactured Housing, and Cluster Development are permitted uses. Min area per dwelling unit is utility-tiered: Class 1 & 2 (any town utility) 30,000 sf; Class 3 (private…
- Front
- 20 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 35% impervious
- Min lot
- 80,000 sf (~1.84 ac)
Seasonal and year-round living on/near Newfound Lake and the Newfound and Fowler Rivers; Single & Two-Family Dwelling permitted. Min area per dwelling unit tiered: Class 1 & 2 30,000 sf; Class 3 (recorded) 80,000 sf (Amended 2024).
- Front
- 20 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 75% impervious
- Min lot
- 20,000 sf (~0.46 ac)
Mixed commercial district along Lake St / Pleasant St; Single & Two-Family Dwelling, Multifamily Dwelling, and Combined Dwelling & Business are permitted uses. Min lot (single & two-family) tiered: Class 1 10,000 sf; Class 2 20,000 sf; Class 3 (recorded) 20,000 sf.
- Front
- 15 ft
- Side
- 0 ft
- Rear
- 15 ft
- Max coverage
- 100% impervious
- Min lot
- —
Traditional downtown core (Central Square, South Main, Pleasant St), entirely Class 1 (town water & sewer) — the only class listed. Minimum lot size 'None'; side setback 'None' (recorded as 0); front 15 ft, rear 15 ft, frontage 50 ft, max lot coverage by impervious cover 100%.
- Front
- 20 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 60% impervious
- Min lot
- 40,000 sf (~0.92 ac)
Lower-density commercial corridor away from the village, mostly unserved by town utilities; Single & Two-Family Dwelling and Combined Dwelling & Business are permitted uses. Min area per dwelling unit (single & two-family or non-residential) tiered: Class 1 & 2 30,000 sf;…
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 75% impervious
- Min lot
- 40,000 sf (~0.92 ac)
Industrial plants, warehousing, manufacturing. Min area tiered: Class 1 20,000 sf (frontage 125 ft); Class 2 30,000 sf (frontage 150 ft); Class 3 (recorded) 40,000 sf (frontage 150 ft). Setbacks 25/25/25 and 75% max impervious cover in all classes.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Bristol 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 Bristol (Grafton County). A detached ADU can be up to 950 sf.
In Bristol's VR zone, ADUs follow the single-family setbacks: 20 ft front, 15 ft side, and 15 ft rear. Bristol has 7 zoning districts in total — see the full table below. Confirm your exact zone with the town.