Build an ADU in Deering.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Deering — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
6 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Deering zoning ordinance · source · 2026-07-07
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 40 ft
- Max coverage
- 30% building
- Min lot
- 87,120 sf (~2.00 ac)
FRONT IS MEASURED FROM THE EDGE OF THE RIGHT-OF-WAY, not centerline: min 50 ft between any building and the edge of a right-of-way (4.1.5.a). Min lot 2 acres (87,120 sf) OR LARGER depending on soil and slope conditions per state standards (4.1.3) — conservative base recorded;…
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Overlay on delineated wetlands; base town-wide setbacks still govern lot lines. No portion of a subsurface wastewater (septic) system within 75 ft of any wetland (3.5.5.a). Wetland area cannot count toward minimum lot acreage (4.1.4).
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Overlay; building setbacks remain the town-wide 50/30/40. Min lot within the overlay is 2 acres (87,120 sf) PER DWELLING UNIT for residential use, or per principal building for non-residential; expressly NOT to be read as requiring additional acreage to add an ADU to a…
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
NFIP-conforming floodplain overlay covering FEMA special flood hazard areas; imposes flood-elevation, anchoring and permitting standards rather than its own setback/lot dimensional table.
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- 20% impervious
- Min lot
- —
Overlay on protected shorelands of 4th-order+ streams, lakes and great ponds (incl Deering Reservoir/Lake, Dudley Pond, Contoocook River, Piscataquog River). NO STRUCTURE within 50 ft of the reference line (high-water line) (4.4.10.c); sheds/gazebos (not garages) may enter…
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Overlay over the Deering Lake (Deering Reservoir) watershed, repealed and replaced March 11, 2025. No fixed setback/lot table of its own; instead ALL 'regulated activities and improvements' require a Planning Board CONDITIONAL USE PERMIT: major CUP for new/expanded building…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Deering 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 Deering (Hillsborough County). A detached ADU can be up to 950 sf.
In Deering's TOWN zone, ADUs follow the single-family setbacks: 50 ft front, 30 ft side, and 40 ft rear. Deering has 6 zoning districts in total — see the full table below. Confirm your exact zone with the town.