How big can an ADU be in Lee?

200 to 1,000 sq ft gross floor area; not larger than the main house, but never capped below 750 sq ft; max 2 bedrooms, per Art. V.E.4.b.i(a)-(c) as read 2026-11-15.

Does the owner have to live on the lot in Lee?

Owner must live in the house or the ADU (proof by Lee voter or vehicle registration) (Art. V.E.4.a).

Can an ADU in Lee be detached?

Attached (in, attached to, or inside an existing detached structure) or detached; one per lot, under Art. V.E.2 (definitions).

Strafford County · New Hampshire

ADU rules in Lee, NH

Lee is a Strafford County town on the Lamprey and Oyster Rivers.

This is a reference guide. Lee is not on our service-area list, so call to ask whether we can take on a build there.

Call (978) 987-0089

Town ADU rules

What’s allowed on your lot in Lee.

Lee allows an ADU of 200 to 1,000 sq ft with a building permit and certificate of occupancy only, attached or detached.

Size limit: 200 to 1,000 sq ft gross floor area; not larger than the main house, but never capped below 750 sq ft; max 2 bedrooms
Where it can go: Attached (in, attached to, or inside an existing detached structure) or detached; one per lot
Owner on site: Owner must live in the house or the ADU (proof by Lee voter or vehicle registration)
Parking: No ADU parking rule in the ordinance
Approval: Building permit and certificate of occupancy only
Rentals: ADU may not be used for short-term rentals or other transient housing
Water setback: No buildings, septic, driveways or parking within 100 ft of the Lamprey, Little, North and Oyster Rivers, Dube and Chesley Brooks and Wheelwright Pond

Allowed

ApprovalAn ADU needs only a building permit application and a certificate of occupancy.Art. V.E.3
How manyOne attached or one detached ADU per lot of record, in every district where residential use is allowed by right (only Zone A).Art. V.E.2
Attached or detachedAttached means within or attached to the house, or completely inside a preexisting detached structure. Detached means neither. An ADU connected to the house must share a wall with it.Art. V.E.2 (definitions)
DesignAttached ADUs need an interior door between the house and the ADU; the door does not have to stay unlocked.Art. V.E.2 (definitions)
Owner on siteThe owner must live in either the house or the ADU as a primary residence, shown by Lee voter or vehicle registration. For a trust or LLC, a beneficiary or owner must live there. Fines under RSA 676:17 if the owner moves out.Art. V.E.4.a
RentalsThe ADU may not be used as transient or temporary housing, including short-term rentals.Art. V.E.4.a
SizeBetween 200 and 1,000 sq ft gross floor area. No ADU may be bigger than the main house, but the town will not cap it below 750 sq ft. Maximum two bedrooms.Art. V.E.4.b.i(a)-(c)
LotADUs follow normal setbacks, except when a legally nonconforming detached accessory structure or nonconforming house is converted. An ADU may not be closer to the front line than the house.Art. V.E.4.b.ii
SepticAdequate water and sewage per RSA 485-A:38; separate systems not required. A septic approval application is required before building; a new system must be installed if the existing one lacks approval or fails.Art. V.E.6
OtherTo discontinue an ADU, the owner notifies the Code Enforcement Officer while it is empty, and the certificate of occupancy is revoked.Art. V.E.7
ShorelandLocal Shoreland Conservation District = all land within 100 ft of the average high-water line of the Lamprey River, Little River, North River, Oyster River, Dube Brook, Chesley Brook and Wheelwright Pond. No roads, driveways, parking, dwellings or other structures (except pump housing), and no wastewater systems. Existing structures may be replaced or remodeled but not expanded. Max 50% of tree basal area may be cut. Separately, the Wet Soils Conservation Zone bars septic tanks and leach fields within 125 ft of any wetland and needs a special exception for listed uses within 75 ft of a wetland. The ordinance does not say it adopts RSA 483-B; it cites RSA 483-B:9 only for agriculture and forestry.Art. XIV.B-D; Art. XV.E-F.1
State lawThe town text still requires an interior door and a shared wall for an attached ADU. State law lets the owner choose how an attached ADU is entered.RSA 674:72, III

Not allowed

Not allowedNo ADU with manufactured housing (RSA 674:31) or with attached single-family dwellings such as townhouses.Art. V.E.5
Not allowedThe ADU may not be made a condominium or owned separately from the house.Art. V.E.4.a
Not allowedNo short-term or transient use of the ADU.Art. V.E.4.a
Not allowedNo ADU larger than the main house (but not capped below 750 sq ft); no more than two bedrooms.Art. V.E.4.b.i
Not allowedNo residential use, so no ADU, in Zone C or Zone LC.Art. VI.A.1; Art. VI-a.B.1

Read 2026-11-15 from Zoning Ordinance, Town of Lee, New Hampshire (Cover: "ADOPTED: April 9, 1966 / LAST REVISED: March 10, 2026"). Anything not listed here, we check with the Lee land-use office for your lot.

Setbacks

Front, side and rear in Lee.

NH RSA 674:71-73 (HB 577) - one attached or detached ADU by right on a single-family lot

Lee's dimensional table, as printed in the ordinance.

District	Front	Side	Rear	Lot / cover / height
Zone AprimaryResidential ZoneArt. V.B.1-3. Zone A frontage 250 feet of contiguous frontage on a public right-of-way. Zone A accessory buildings: Same as any building (setback applies to "any building").	50 feet from the public and private right-of-way	25 feet (35 feet when the line is along a right of way)	25 feet (35 feet when the line is along a right of way)	85,000 square feet of contiguous land which is suitable for development · No Zone A coverage limit found; 10% impervious for the part of a lot in the Aquifer Conservation District (Art. XIII.D.1) · Height No Zone A height limit found in the ordinance (35 ft appears only in the condominium and multifamily articles)

Verified 2026-11-15 against Zoning Ordinance, Town of Lee, New Hampshire. Towns amend ordinances, so confirm with the land-use office before you build. Official source

FAQ

ADUs in Lee.

How big can an ADU be in Lee?: 200 to 1,000 sq ft gross floor area; not larger than the main house, but never capped below 750 sq ft; max 2 bedrooms, per Art. V.E.4.b.i(a)-(c) as read 2026-11-15.
Does the owner have to live on the lot in Lee?: Owner must live in the house or the ADU (proof by Lee voter or vehicle registration) (Art. V.E.4.a).
Can an ADU in Lee be detached?: Attached (in, attached to, or inside an existing detached structure) or detached; one per lot, under Art. V.E.2 (definitions).

Planning an ADU in Lee?

Call (978) 987-0089 and we will say whether we can build there. See the ADU models

Get a quote Call (978) 987-0089