Build an ADU in Chichester.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Chichester — 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 Chichester zoning ordinance · source · 2026-07-06
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
PRIMARY single-family residential district (smallest residential minimum lot; density greater than RA). Min lot 2 contiguous acres (87,120 sf) + 200 ft road frontage for single-family; 2.5 acres (108,900 sf) + 250 ft frontage for two-family.
- Front
- 30 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 217,800 sf (~5.00 ac)
Min lot 5 contiguous acres (217,800 sf) + 300 ft road frontage for single- and two-family dwellings. Each lot must contain one Buildable Acre. Front setback of 30 ft is measured from the EDGE of the State/town-maintained highway Right-of-Way, not centerline.
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 20 ft
- Max coverage
- 50% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Min lot 1 acre (43,560 sf) with one-half buildable acre; lot frontage 75 ft Impervious surface coverage is TIERED by parcel size: 50% for parcels MORE than 2 acres, 75% for parcels UNDER 2 acres (recorded max is the 50% large-parcel figure; small parcels under 2 ac allow up…
- Front
- 40 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 90% lot
- Min lot
- 43,560 sf (~1.00 ac)
Each lot must contain one Buildable Acre (43,560 sf); multi-family adds 0.5 acre per unit beyond the first. Front: no building nearer than 40 ft from the EDGE of State/town-maintained road Right-of-Way (not centerline).
- Front
- 15 ft
- Side
- 15 ft
- Rear
- 15 ft
- Max coverage
- 70% lot
- Min lot
- 43,560 sf (~1.00 ac)
Each lot must contain one Buildable Acre (43,560 sf); multi-family adds 0.5 acre per unit beyond the first. Residential single-family/duplex min lot 2 acres (87,120 sf)/200 ft frontage, two-family 2.5 acres/250 ft Setback basis not stated as centerline.
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Town-wide, non-mapped, NON-BUILDABLE district: land lacking the minimum road frontage for a developable lot. May be subdivided only if plat/deed restrict it to a non-buildable dwelling lot with at least a 50 ft Right-of-Way to a town/state road.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Chichester 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 Chichester (Merrimack County). A detached ADU can be up to 950 sf.
In Chichester's R zone, ADUs follow the single-family setbacks: 30 ft front, 15 ft side, and 15 ft rear. Chichester has 6 zoning districts in total — see the full table below. Confirm your exact zone with the town.