Build an ADU in New London.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in New London — 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 New London zoning ordinance · source · 2026-07-07
- Front
- 25 ft
- Side
- 20 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Principal residential district (Art V permits single-family or two-family dwellings). TIERED BY UTILITIES — conservative no-utilities tier recorded: lots NOT using public sewer and water require min 2 acres (87,120 sf), 150 ft continuous frontage, side yards 20 ft, density 1…
- Front
- 25 ft
- Side
- 20 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
Same Article V district regulations as R-1 but no public-utility tier: min lot 2 acres (87,120 sf), 150 ft continuous frontage, density 1 family per 2 acres (V.B.2). Side yards 20 ft on ALL R-2 lots (V.C.2); front 25 ft from ROW line; rear 15 ft; corner lots 25 ft abutting…
- Front
- 50 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- 174,240 sf (~4.00 ac)
Permits any Residential District use (incl single/two-family dwellings) plus general farming, veterinarian, greenhouse, country club, forestry (VI.A). Min lot 4 acres (174,240 sf) with 200 ft continuous frontage (curving-street averaging allowed); density 1 family/4 acres (VI.B).
- Front
- 30 ft
- Side
- 10 ft
- Rear
- 10 ft
- Max coverage
- —
- Min lot
- —
All Residential District uses permitted in the same manner, plus lodging, apartments/multi-family, shops, restaurants, offices, mixed use; some uses by special exception (VII.A). Front: min 30 ft yard between the nearest RIGHT-OF-WAY and the extreme front of any building, but…
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 435,600 sf (~10.00 ac)
Open-space district that still permits SINGLE-FAMILY DWELLINGS plus forestry, agriculture, golf course, stables, water recreation, nurseries (VIII.A). Min lot 10 acres (435,600 sf), 200 ft continuous road frontage, density 1 family/10 acres (VIII.C); lakefront lots need 300…
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- —
- Min lot
- 1,089,000 sf (~25.00 ac)
Large-tract forest district; single-family dwellings and accessory structures ARE permitted (IX.A.6) along with forestry, agriculture, wildlife refuges; home businesses and recreational structures by special exception (IX.B).
- Front
- —
- Side
- —
- Rear
- —
- Max coverage
- —
- Min lot
- —
Colby-Sawyer College district. College buildings: 100 ft setback from any college property line directly abutting a residential-zone property, or 50 ft from a property line abutting a public ROW (Seamans Rd/Main St) (X.1.B.3); non-building activities 50-100 ft depending on…
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- —
New London Hospital district; licensed medical facilities and supporting activities permitted, others by special exception (X.3.A).
- Front
- 25 ft
- Side
- 25 ft
- Rear
- 25 ft
- Max coverage
- —
- Min lot
- —
Collegiate outdoor recreation district (Kelsey Athletic Campus).
- Front
- 25 ft
- Side
- 20 ft
- Rear
- 15 ft
- Max coverage
- —
- Min lot
- 87,120 sf (~2.00 ac)
New London Barn Playhouse district. Yard/setback and lot-area requirements CONFORM TO THE R-1 RESIDENTIAL DISTRICT (X.4.B.1-2), so the conservative no-utilities R-1 tier is recorded: front 25, side 20, rear 15, min lot 2 acres (10,000 sf where public sewer AND water serve the…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
New London 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 New London (Merrimack County). A detached ADU can be up to 950 sf.
In New London's R-1 zone, ADUs follow the single-family setbacks: 25 ft front, 20 ft side, and 15 ft rear. New London has 10 zoning districts in total — see the full table below. Confirm your exact zone with the town.