Build an ADU in Berlin.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Berlin — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
8 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Berlin zoning ordinance · source · 2026-07-07
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- 40% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Berlin's principal single-family district (permitted use: single family dwelling, 17-62). District base minimum lot is 5,000 sf with 50 ft frontage (17-63, Ord 1/3/2022), BUT the town-wide Sec 17-22 overrides this where municipal utilities are absent: min lot 1 acre (43,560…
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- 40% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Medium-density, up to two dwelling units per structure (17-71, 17-76.2). District base minimum lot 5,000 sf, 50 ft frontage (17-73, Ord 1/3/2022); town-wide Sec 17-22 raises this to 1 acre where city sewer OR water is absent and 2 acres where both are absent — recorded value…
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- 45% impervious
- Min lot
- 87,120 sf (~2.00 ac)
High-density multi-family district (17-81). District base minimum lot 10,000 sf for the first dwelling unit + 1,500 sf per additional unit, 100 ft frontage (17-83). Town-wide Sec 17-22 overrides where utilities absent: 1 acre (one of sewer/water missing) / 2 acres (both…
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 25% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Low-density rural district that relies primarily on on-site sewer and water (17-51). Minimum lot 2 acres (87,120 sf), 200 ft frontage (17-53). The 2-acre district minimum already equals the town-wide Sec 17-22 no-utilities floor, so no tiering adjustment needed.
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- 75% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Mixed recreation/residential/retail gateway district (17-51a). 2 acres = 87,120 sf); for nonresidential uses the minimum lot is soil-based, not less than 10,000 sf (17-53a). Frontage 200 ft Setbacks: front 50 ft (primary and accessory), rear 25 ft, side 25 ft (17-54a).
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- 1,500 sf (~0.03 ac)
Pedestrian-scale downtown core; a mixture of commercial, retail, government and housing uses is encouraged, with multi-family dwellings permitted (17-91, 17-92). Minimum lot 1,500 sf, 15 ft frontage (may be reduced to 750 sf / 10 ft by special exception) (17-93).
- Front
- 20 ft
- Side
- 6 ft
- Rear
- 20 ft
- Max coverage
- 75% impervious
- Min lot
- 10,000 sf (~0.23 ac)
Intense commercial + light-industrial district (17-101). Recorded values are for NONRESIDENTIAL uses: minimum lot 10,000 sf, 100 ft frontage (17-103.1.b); front 20 ft (primary), rear 20 ft, side 6 ft — each side increased 1 ft per 1 ft of building height over 25 ft (17-104.2).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 75% impervious
- Min lot
- 10,000 sf (~0.23 ac)
Industrial district for heavy/light industry, warehousing and freight (17-111, 17-112). Minimum lot 10,000 sf (plus 2 sf of open space, including parking, per 1 sf of building footprint), 100 ft frontage (17-113).
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Berlin 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 Berlin (Coös County). A detached ADU can be up to 950 sf.
In Berlin's RS zone, ADUs follow the single-family setbacks: 25 ft front, 10 ft side, and 25 ft rear. Berlin has 8 zoning districts in total — see the full table below. Confirm your exact zone with the town.