Build an ADU in Litchfield.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Litchfield — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
12 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Litchfield zoning ordinance · source · 2026-07-06
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
PRIMARY single-family residential district. Single-Family Uses row: min lot area 1 acre (43,560 sf) of minimum contiguous DRY lot size, min frontage 150 ft, front/ROW setback 50 ft (applies to both the front lot line and all public rights-of-way), rear 20 ft, side 20 ft Sheds…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 65,340 sf (~1.50 ac)
Same base Residential District, Two-Family (duplex) Uses row of the Section 310.00 table: min lot area 1.5 acres (65,340 sf) contiguous dry, min frontage 200 ft, front/ROW 50 ft, rear 20 ft, side 20 ft Shed exception per note 4 (<=200 sf need only 10 ft side/rear).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Base Residential District, 'All Other Uses' row of the Section 310.00 table (non-single/non-two-family permitted uses in the Residential District): min lot area 1 acre (43,560 sf) contiguous dry, min frontage 150 ft, front/ROW 50 ft, rear 20 ft, side 20 ft No coverage % in…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Overlay (Sections 525-527) allowing multi-family residences in addition to underlying-district uses. Section 310.00 row: min lot area 2 acres (87,120 sf), min frontage 200 ft, front/ROW 50 ft, rear 20 ft, side 20 ft Table note 5: two-acre minimum is for up to 3 dwelling…
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 21,780 sf (~0.50 ac)
Alternative cluster-style residential development (Section 575). Section 310.00 row: min individual lot 0.5 acre (21,780 sf) contiguous dry, min frontage 90 ft (on a Class V roadway or higher), rear 20 ft, side 20 ft The '30 feet' front figure in the table is the…
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Floating/approval overlay: the Planning Board may approve designation of an RMH District (manufactured housing parks) in any district except the Southern Commercial/Industrial Service district, on application (Sections 505.00-506.02).
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 65% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (200 ft if fronting Route 102 or created on/after 3/14/1989 fronting Route 102/3A, note 7), front/ROW 50 ft, rear 20 ft, side 20 ft Note 8: buildings must be set back from side/rear >= the…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 65% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (200 ft if fronting Route 3A, per note 7), front/ROW 50 ft, rear 20 ft, side 20 ft Note 8 (side/rear setback >= building height) and note 9 (Planning-Board-approved lot size, never < 1 dry…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 65% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (200 ft if fronting Route 102/3A per note 7), front/ROW 50 ft, rear 20 ft, side 20 ft Notes 8 and 9 apply. Section 802.03: max 65% site impervious coverage.
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 65% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (note 7), front/ROW 50 ft, rear 20 ft, side 20 ft Notes 8 and 9 apply. Section 902.04: max 65% site impervious coverage.
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 75% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (note 7), front/ROW 30 ft, rear 20 ft, side 20 ft Notes 8 (side/rear setback >= building height) and 9 (Planning-Board-approved lot size, never < 1 dry acre) apply.
- Front
- 30 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- 75% impervious
- Min lot
- 43,560 sf (~1.00 ac)
Section 310.00 row: min lot 1 acre (43,560 sf) contiguous dry, min frontage 150 ft (note 7), front/ROW 30 ft, rear 20 ft, side 20 ft Notes 8 and 9 apply. Section 952.03: max 75% site impervious coverage.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Litchfield 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 Litchfield (Hillsborough County). A detached ADU can be up to 950 sf.
In Litchfield's R-SF zone, ADUs follow the single-family setbacks: 50 ft front, 20 ft side, and 20 ft rear. Litchfield has 12 zoning districts in total — see the full table below. Confirm your exact zone with the town.