Build an ADU in Auburn.
New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Auburn — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.
7 districts
Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.
Verified against the official Auburn zoning ordinance · source · 2026-07-06
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 5% building
- Min lot
- 87,120 sf (~2.00 ac)
PRIMARY single-family residential district - per sec 4.06(1) the R-1 District 'is intended to be primarily residential in character with very limited accessory uses.' Single Family Detached Dwelling and Accessory Dwelling Unit are permitted by right (sec 4.06(2)).
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 5% building
- Min lot
- 87,120 sf (~2.00 ac)
Second residential district - 'a somewhat more rural area with a greater variety of residential and accessory uses permitted' (sec 4.06(1)). Same density and dimensional requirements as R-1 (identical 4.06(6) table): min lot 2 acres (87,120 sf), min frontage 200 ft, yards…
- Front
- 50 ft
- Side
- 50 ft
- Rear
- 50 ft
- Max coverage
- 5% building
- Min lot
- 130,680 sf (~3.00 ac)
Largest / most-restrictive district (order of restrictiveness R > R-1 > R-2 > V > C-2 > C-1 > I per sec 4.03(6)); covers remote agricultural/forestry/water-quality areas. Min lot size 3 acres (130,680 sf); min frontage 300 ft All three yards 50 ft from property lines…
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 40% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Regional commercial district. Min lot 2 acres (87,120 sf); min frontage 200 ft; yards from property lines front 50 / side 30 / rear 50 ft; max height 35 ft / 3 stories. 'Lot coverage by impervious material in both commercial districts shall be a maximum of 40%' (sec 4.07(1))…
- Front
- 50 ft
- Side
- 30 ft
- Rear
- 50 ft
- Max coverage
- 40% impervious
- Min lot
- 87,120 sf (~2.00 ac)
Local low-intensity commercial district 'in keeping with the Village character' (sec 4.07(1)). Same dimensional table as C-1 (sec 4.07(6)): min lot 2 acres (87,120 sf), frontage 200 ft, yards front 50 / side 30 / rear 50 ft from property lines, max height 35 ft / 3 stories,…
- Front
- 50 ft
- Side
- 20 ft
- Rear
- 20 ft
- Max coverage
- —
- Min lot
- 43,560 sf (~1.00 ac)
Listed as one of the seven districts at sec 4.02, but sec 4.08(2) describes it as an OVERLAY over an underlying C-2 (and R-2) zone along Route 121 / Manchester Rd / Raymond Rd Dimensional requirements (sec 4.08(4)): min lot 1 acre (43,560 sf); min frontage 100 ft; yards from…
- Front
- 50 ft
- Side
- —
- Rear
- —
- Max coverage
- 40% impervious
- Min lot
- 130,680 sf (~3.00 ac)
Industrial district. Min lot size 3 acres (130,680 sf) - reducible by Planning Board discretion if served by municipal water and/or sewer (sec 4.09(4) note *). Min frontage 300 ft Front yard 50 ft from property line; SIDE and REAR yards are 'To be determined by Site Plan…
Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.
Auburn 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 Auburn (Rockingham County). A detached ADU can be up to 950 sf.
In Auburn's R-1 zone, ADUs follow the single-family setbacks: 50 ft front, 30 ft side, and 50 ft rear. Auburn has 7 zoning districts in total — see the full table below. Confirm your exact zone with the town.