Build an ADU in Littleton.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Littleton — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
10 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Littleton zoning ordinance · source · 2026-07-07
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Town's principal single-family residential district: 'low to medium density urban character having public water and sewer facilities available' (4.02.01). LOT-AREA TIERING: the table lists lot area 'n/a' for R-I because it assumes town water+sewer; Sec 5.05 sets the binding…
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Same low-to-medium-density urban character as R-I but also permits a single mobile home on a permanent masonry foundation (4.02.02). Lot area 'n/a' in table (assumes town water+sewer); Sec 5.05 floor governs unserviced lots (2 ac / 87,120 sf if both on-site; 1 ac if one).
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Suburban/transitional district maintaining reasonable rural character (4.02.03). Table of Lot Requirements: minimum lot area 2 acres (87,120 sf), width 250 ft, depth n/a, front 40, side 25, rear 25, height 35 ft / 2.5 stories.
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 130,680 sf (~3.00 ac)
Rural district preserving openness, agriculture, forestry and limited commercial/industrial uses (4.02.04). Table of Lot Requirements: minimum lot area 3 acres (130,680 sf), width 300 ft, depth n/a, front 50, side 50, rear 50, height 35 ft / 3 stories.
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Commercial districts for continued business growth (4.02.05, covering Commercial I, II, III & IV). Table of Lot Requirements row 'Commercial I & IV (Town Services)': lot area n/a, width 100 ft, depth 250 ft, front 40, side 25, rear 25, height 35 ft / 3 stories.
- Front
- 25 ft
- Side
- 10 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Table of Lot Requirements row 'Commercial II (Town Services)': lot area n/a, width 100 ft, depth 150 ft, front 25, side 10, rear 25, height 35 ft / 3 stories. Table assumes town water+sewer; Sec 5.05 unserviced floor (2 ac / 87,120 sf both on-site) governs otherwise.
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Table of Lot Requirements row 'Commercial III (Town Services)': lot area n/a, width 300 ft, depth 250 ft, front 40, side 25, rear 25, height 35 ft / 3 stories. Table row assumes town water+sewer (lot area n/a); Sec 5.05 imposes the unserviced floor (2 acres / 87,120 sf for a…
- Front
- 40 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Industrial district (4.02.06). Table of Lot Requirements: lot area 1 acre, width 200 ft, depth n/a, front 40, side 25, rear 25, height 35 ft / 3 stories. The 1-acre table figure assumes utilities; Sec 5.05 unserviced floor (2 ac / 87,120 sf both on-site) governs otherwise.
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Mixed-use district encouraging residential and institutional development while preserving the rural-oriented landscape and promoting a mix of dwellings and compatible uses (4.02.07).
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Cemetery-Protected Area overlay-style district (approved 1985 Town Meeting; use regulations at 4.02.08). Not a residential building district and it carries no row in the Table of Lot Requirements, so no dimensional setbacks or minimum lot area are stated for it in the ordinance.
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Littleton 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 Littleton (Grafton County). A detached ADU can be up to 950 sf.
In Littleton's R-I zone, ADUs follow the single-family setbacks: 25 ft front, 10 ft side, and 25 ft rear. Littleton has 10 zoning districts in total — see the full table below. Confirm your exact zone with the town.