Hollis, New Hampshire · Hillsborough County

Build an ADU in Hollis.

Allowed by-right · RSA 674:71-73

New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Hollis — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.

All zoning districts in Hollis

14 districts

Each district's single-family setbacks — which your ADU follows. The primary residential district is highlighted.

Verified against the official Hollis zoning ordinance · source · 2026-07-06

R&APrimary

Residential and Agricultural District

Ch X.G.5 (Area and Height Regulations, R&A); districts Ch VII.A.7; coverage Ch IX.E.4; height Ch IX.I.1; front measured per Ch VIII FRONT YARD def

Front: 50 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

PRIMARY residential district (Ch X.G). Intent: 'to encourage farming in Town while recognizing that growth and development will occur and should therefore be located in these areas where physical site conditions may be favorable, and critical Town services are available.'…

Rural Lands Zone

Ch X.H.5 (Area Height Regulations, RL); districts Ch VII.A.8; coverage Ch IX.E.4; height Ch IX.I.1

Front: 100 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

Ch X.H. Intent: 'to encourage farming in Town and to permit limited development in areas where physical site conditions are problematic or access to Town services is restricted.' PERMITTED USES include single- and two-family dwellings and 'Accessory dwelling units according…

Recreational Zone

Ch X.F.5 (Area and Height Regulations, Recreational); districts Ch VII.A.6; coverage Ch IX.E.4; height Ch IX.I.1

Front: 50 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

Ch X.F. Intent: 'to allow residential and recreational development around local bodies of water while protecting water quality.' Covers land within 600 ft of the shores of Silver Lake, Pennichuck Pond, Rocky Pond, Flint Pond, the Nissitissit River, Nashua River and Dunklee…

WSC

Water Supply Conservation Zone

Ch X.J.5 (Area and Height Regulations, WSC); districts Ch VII.A.10; ADU special-exception Ch X.J.4.b; coverage Ch IX.E.4; height Ch IX.I.1

Front: 50 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

Ch X.J. Intent: to protect a large, high-quality underground water resource serving the Hollis school system and residences. Dimensional standards Ch X.J.5: MIN LOT AREA 2 acres/dwelling unit (87,120 sf); MIN FRONTAGE 200 ft; FRONT YARD 50 ft (100 ft on scenic roads); SIDE…

Town Center Zone

Ch X.I.6 (Area and Height Regulations, Town Center); districts Ch VII.A.9; coverage Ch IX.E.4; height Ch IX.I.1; ADU Ch IX.K

Front: 50 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

Ch X.I. Dimensional standards Ch X.I.6: MIN LOT AREA 2 acres/dwelling unit (87,120 sf); MIN FRONTAGE 200 ft; FRONT YARD 50 ft (100 ft on scenic roads); SIDE YARD 35 ft principal, 15 ft accessory, AND a minimum 100 ft between houses; REAR YARD 35 ft principal, 15 ft accessory;…

MH-2

Mobile Home-2 Zone

Ch X.E.4 (Area and Height Regulations, MH-2); districts Ch VII.A.5; coverage Ch IX.E.4; height Ch IX.I.1

Front: 50 ft
Side: 35 ft
Rear: 35 ft
Max coverage: 25% impervious
Min lot: 87,120 sf (~2.00 ac)

Ch X.E. Dimensional standards Ch X.E.4: MIN LOT AREA 2 acres/dwelling unit (87,120 sf); MIN FRONTAGE 200 ft on a public road; FRONT YARD 50 ft (100 ft on scenic roads); SIDE YARD 35 ft from house/principal structure to lot line, 15 ft from accessory structures; REAR YARD 35…

MH-1

Mobile Home-1 Zone

Ch X.D.5 (Area and Height Regulations, MH-1) + Ch X.D.6.a; districts Ch VII.A.4; coverage Ch IX.E.4; height Ch IX.I.1

Front: 25 ft
Side: 15 ft
Rear: —
Max coverage: 25% impervious
Min lot: 15,000 sf (~0.34 ac)

Ch X.D. Dimensional standards Ch X.D.5: MIN LOT AREA per mobile home 15,000 sf (5,000 sf of which must be unencumbered open space); MIN LOT WIDTH 100 ft at the setback line; MIN SIDE YARD 15 ft; MIN FRONT YARD 25 ft; mobile-home-park road ROW min width 40 ft; MIN SIZE OF…

A&B

Agricultural and Business Zone

Ch X.A.6 (Area and Height Requirements, A&B); districts Ch VII.A.1; coverage Ch IX.E.1.b/E.2.b; height Ch IX.I.1

Front: 50 ft
Side: 15 ft
Rear: 15 ft
Max coverage: 35% building
Min lot: 32,670 sf (~0.75 ac)

Ch X.A. Dimensional standards Ch X.A.6: MIN LOT SIZE 3/4 acre (32,670 sf) for individual businesses; FOR RESIDENCES the minimum lot size is 2 ACRES per dwelling unit (87,120 sf) — the 32,670 sf shown is the business figure, so an ADU on a residential lot here follows the…

Commercial Zone

Ch X.B.3 (Area and Height Requirements, Commercial); districts Ch VII.A.2; coverage Ch IX.E.1.a/E.2.a and Ch X.B.3.f; height Ch IX.I.1

Front: 50 ft
Side: 15 ft
Rear: 15 ft
Max coverage: 50% building
Min lot: 43,560 sf (~1.00 ac)

Ch X.B. Dimensional standards Ch X.B.3: MIN LOT SIZE 1 acre (43,560 sf) for individual businesses; FRONT YARD 50 ft from public roads, 25 ft from internal roads; SIDE YARD 15 ft, 35 ft when abutting a residential zone; REAR YARD 15 ft, 35 ft when abutting a residential zone;…

Industrial Zone

Ch X.C.3 (Area and Lot Requirements, Industrial); districts Ch VII.A.3; coverage Ch IX.E.1.a/E.2.a and Ch X.C.3.f; height Ch IX.I.1

Front: 50 ft
Side: 25 ft
Rear: 25 ft
Max coverage: 50% building
Min lot: 43,560 sf (~1.00 ac)

Ch X.C (labeled INDUSTRIAL ZONE (IN) in Ch VII.A.3; 'I' in Ch X headings). Dimensional standards Ch X.C.3: MIN LOT SIZE 1 acre (43,560 sf); MIN FRONTAGE 200 ft; FRONT YARD 100 ft when abutting a state highway, 50 ft on all other roads (50 shown = other-roads base, 100 =…

APO

Aquifer Protection Overlay Zone

Ch X.K (APO) + Ch IX.E.3 (15% impervious cap); overlay listed Ch VII.B.1

Front: —
Side: —
Rear: —
Max coverage: 15% impervious
Min lot: —

OVERLAY (Ch X.K; Ch VII.B.1). 'A zoning overlay district which imposes additional requirements and restrictions to those of the underlying district zoning. Its numeric dimensional standard is the coverage cap: per Ch IX.E.3, except for the Industrial Zone, impermeable…

WCO

Wetland Conservation Overlay Zone

Ch X.M (WCO) + Ch VII.B.3 (100-ft buffer) + Ch IX.E.3 (15% impervious cap)

Front: —
Side: —
Rear: —
Max coverage: 15% impervious
Min lot: —

OVERLAY (Ch X.M; Ch VII.B.3). Covers wetlands, surface waters, hydric soils, and a 100-ft buffer around them (measured from the mean high-water mark, delineated wetland edge, or hydric-soil limit, whichever is most restrictive).

FPO

Flood Plain Overlay Zone

Ch X.L (FPO); overlay listed Ch VII.B.2

Front: —
Side: —
Rear: —
Max coverage: —
Min lot: —

OVERLAY (Ch X.L; Ch VII.B.2). A regulatory flood-protection overlay: it imposes construction/elevation standards but does NOT set its own front/side/rear yard setbacks, min lot size, or a lot-coverage percentage for dwellings — those come from the underlying base district.

Multi-Family Overlay Zone (Workforce Housing)

Ch X.N.2 (MF General Standards); overlay listed Ch VII.B.4

Front: —
Side: —
Rear: —
Max coverage: —
Min lot: 174,240 sf (~4.00 ac)

OVERLAY (Ch X.N; Ch VII.B.4). GENERAL STANDARDS (Ch X.N.2): density max 4 units/acre on Net Tract Area; MIN LOT AREA 4 acres (174,240 sf) with at least 50 ft of frontage; garden-style structures limited to 2 stories, townhouse style up to 2 stories with first-floor garage; a…

Form-based and downtown districts may use build-to lines instead of fixed setbacks (shown as “—”); verify your parcel's district before you build.

Confirm your zoning

Hollis zoning ordinance ↗Hollis parcel map (MapGeo) ↗

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Hollis ADU FAQ

Can I build an ADU in Hollis, NH?

Yes. Under NH RSA 674:71-73 (HB 577), one accessory dwelling unit is allowed by-right on single-family lots statewide, including Hollis (Hillsborough County). A detached ADU can be up to 950 sf.

What are the ADU setbacks in Hollis?

In Hollis's R&A zone, ADUs follow the single-family setbacks: 50 ft front, 35 ft side, and 35 ft rear. Hollis has 14 zoning districts in total — see the full table below. Confirm your exact zone with the town.

ADU rules in nearby Hillsborough County towns

Amherst Antrim Bedford Bennington Brookline Deering Francestown Goffstown