ADU rules in Grand Forks

Grand Forks's Land Development Code (City Code Chapter XVIII) has no accessory dwelling unit use: quoted searches of the whole city code for 'accessory dwelling', 'accessory apartment', 'garage apartment', 'second dwelling', 'accessory living' and 'granny' return zero hits, and the city's own October 2025 Middle Housing Code Analysis says 'ADUs are not permitted in any residential zones.' The only detached accessory living unit the code allows is a guest house, defined in Sec. 18-0204 as 'an adjunct living unit, with sleeping area(s) and a bathroom, with or without kitchen facilities', and Table 18-0206(3) lists it as a conditional use (C/C) only in the A-1 agricultural preservation and A-2 agricultural urban reserve districts. Under Sec. 18-0206(3)(N) it needs a parcel of at least 5 acres, one per parcel, an owner living on the property, and a recorded covenant against separate sale, lease or rental. In R-1 through R-4, U-D and the other residential districts a second detached dwelling is not a listed use, and the Board of Zoning Adjustment may not grant use variances (Sec. 18-0602(1)).

There is no attached or internal ADU category either, but a second unit inside or attached to a house is lawful in some districts as a two-family dwelling, defined in Sec. 18-0204 as 'A dwelling designed for and occupied by not more than two (2) families and having an unpierced common wall, roof, or floor.' Two-family dwellings are permitted by right in R-2 (Sec. 18-0209(2)(B)), and through R-2's use list in R-3 and R-4 (Secs. 18-0210(2)(A), 18-0211(2)(A)) and the U-D university district (Sec. 18-0221(2)(A)), on lots of at least 7,000 sq ft and 50 ft wide (6,000 sq ft suffices for a single-family home). R-1, which covers over 70 percent of the city's residentially zoned land, permits only single-family detached dwellings (Sec. 18-0208(2)(A)); its one multifamily route is a conditional use limited to existing historic structures, and Sec. 18-0208(11)(A)3 says 'Conversion of existing single family structures to multifamily is prohibited.' Even where allowed, the result is a duplex of two co-equal units, not a subordinate accessory unit.

Because the code has no ADU use, it sets no ADU size. Sec. 18-0206(3)(N) gives the guest house no floor-area limit of its own; Table 18-0206(5) caps buildings at 35 ft and caps detached accessory structure area at 2,400 sq ft (attached 1,200 sq ft) in A-1 and A-2, but whether that accessory cap governs a guest house, which the table lists as a separate use, is not stated. For the two-family route there is no cap on either unit; the limits are a 7,000 sq ft lot at least 50 ft wide, 2.5 stories and 35 ft (Sec. 18-0209(5)), and impervious surface of 40 percent of the lot in R-2 (45 percent in R-3). Ordinary accessory buildings in town (garages, sheds) are capped at 1,000 sq ft of total accessory building area on lots under 10,000 sq ft and 1,400 sq ft on larger lots (Sec. 18-0305(4), Ord. No. 4899, 12-16-2024), but none of them may be a dwelling.

It depends on the route. The guest house conditional use requires that 'The owner must reside on the real property and said property must be the owner's primary place of residence' (Sec. 18-0206(3)(N)3), and that the guest house 'shall not be used in a fashion as to constitute a second primary residential use on the property' ((N)4); the permit is indefinite but revocable for any violation ((N)1 and (N)10). The two-family dwelling route in R-2, R-3, R-4 and U-D carries no residency condition (Sec. 18-0209(2)(B) lists it as a plain permitted use), so both units of a duplex may be rented. North Dakota has no statute imposing or preempting ADU owner occupancy, and the Legislative Assembly does not meet again until January 2027.

Ordinance No. 4956, adopted 7-6-2026 and not yet codified on Municode, replaced the Sec. 18-0302 parking schedule. Its Schedule A (Sec. 18-0302(17)(A)) requires 2 spaces for an owner-occupied single-family home ('Detached, attached (one unit/lot)') and keeps the 2006 rental rule: 'Every single- or two-family dwelling placed into use for rental purposes, in whole or in part, after January 17, 2006, shall provide 1 off-street parking space for each bedroom in the dwelling.' So converting a house into a duplex with a rented unit means one space per bedroom across both units. New Sec. 18-0302(8)(E) lets developments of four units or fewer deduct one space per 25 ft of usable local-street frontage next to the lot, and Sec. 18-0302(14)(D) lets the planning director approve reductions up to 10 percent (more needs the Planning and Zoning Commission). Neither the old nor the new schedule has a guest house line; Sec. 18-0302(8)(D) leaves unlisted uses to the zoning administrator's similar-use determination.

It depends on the route and district. A two-family dwelling in R-2, R-3, R-4 or U-D is a permitted use, so a conversion or new duplex needs only a building permit reviewed by the zoning administrator (Secs. 18-0501, 18-0506(1)), with no hearing. A guest house in A-1 or A-2 is a conditional use: application to the Planning and Zoning Commission, at least one public hearing, a recommendation, and a decision by the City Council (Sec. 18-0703(1)-(2)), with the conditions of Sec. 18-0206(3)(N) attached. In R-1 there is no permit path at all: a second unit is neither permitted nor conditional, the Board of Zoning Adjustment may not vary uses (Sec. 18-0602(1)), and only a rezoning or a PUD (Sec. 18-0223) adopted by City Council ordinance could allow one.

A guest house may house 'family members and guests without compensation' and 'may not be rented, leased or sold separately' from the main home (Sec. 18-0204), backed by a covenant recorded with Grand Forks County (Sec. 18-0206(3)(N)8). A unit in a two-family dwelling may be rented, but every rental unit in a building with fewer than three rental units needs a residential rental license from the city ($20 per unit per year, expiring each December 31; Secs. 21-0603, 21-0604(1), 21-0607, 21-0608), and an owner living more than 60 miles away must name a local agent (Sec. 21-0606). Grand Forks has no short-term rental ordinance (quoted searches for 'short-term rental', 'short term rental' and 'vacation rental' return nothing); nightly rentals would most likely fall under the hotel/motel license, which covers any building 'or any part thereof' furnishing sleeping accommodations to the public for periods of less than 30 days (Secs. 21-1101(1), 21-1102), and the 0.25 percent city lodging tax (Sec. 22-0503), but the city has published no guidance applying either to a home.