ADU rules in Grand Island

Grand Island's zoning code has no accessory dwelling unit definition or ADU standard; a backyard unit is simply a second dwelling unit. Every residential district lists "Dwelling units" as a permitted principal use, and Ordinance 10,025 (enacted June 24, 2025, effective July 9, 2025) added §36.27.1, which lets multiple detached buildings count as a single principal building when they stay within the district's density, coverage and setback limits. The density table is the gate: a second unit needs 18,000 sq ft of lot in R-1 (9,000 sq ft per unit), 12,000 sq ft in R-2 (6,000 per unit), and 18,000 sq ft in LLR with city sewer and water, while a standard 6,000 sq ft lot qualifies in R-3, R-3SL (3,000 per unit) and R-4 (1,000 per unit), and RO sets no per-unit minimum. So a detached unit is allowed by right on large lots or in the denser districts, but not on a typical R-1 or R-2 lot.

An attached or internal unit (a basement apartment or addition with its own kitchen, bath and sleeping area) makes the house a two-family dwelling. The Zoning Matrix lists "Dwelling, two-family" as permitted in LLR, R-1, R-2, R-3, R-4, RO, RM and RD, so no hearing is needed, but the same minimum lot area per dwelling unit applies: 18,000 sq ft in R-1, 12,000 in R-2, 6,000 in R-3 and R-3SL. A no-kitchen "guest building" (a permitted accessory use in LLR and R-1) is not a dwelling unit and cannot be rented.

The code sets no size limit for a second dwelling unit as such. A detached unit counted as part of the principal building under §36.27.1 must keep all buildings within the district's maximum ground coverage (30 percent in R-1, 35 percent in R-2, 50 percent in R-3 and R-3SL, 60 percent in R-4, 25 percent in LLR) and its height limit (35 ft in LLR through R-3). If the city instead treats the structure as an accessory building, §36.27.2(E) and (F) limit all detached accessory buildings to 50 percent of the allowable coverage, any single one to 35 percent of it, and its height to 125 percent of the house. The "Dwelling, Single Family" definition also requires at least 900 sq ft of above-grade floor area for single-story construction, which may set a minimum for a detached single-story house.

Nothing in Chapter 36 requires the owner to live on a lot with two dwelling units, and a code-wide search for owner-occupancy language found nothing in the zoning chapter. The only owner-residence rule in the zoning code applies to bed and breakfast inns ("The operator of the inn shall live on the premises"), not to dwellings. Nebraska has no state ADU statute bearing on owner occupancy.

The parking schedule requires two spaces per dwelling unit for single-family attached and detached dwellings and for duplexes, so a second unit adds two required spaces. For a building with three or fewer dwelling units, one space per unit may sit within the front yard setback if not directly in front of the building. The Central Business District described in §36-96(B)(1) is exempt from the off-street requirements.

Dwelling units and two-family dwellings are permitted principal uses in the residential districts, and §36.27.1 applies by its own terms with no hearing or special permit, so a second unit that meets density, coverage and setbacks needs only a building permit. The city's 2025 report to the Legislature describes ADUs as "permitted in all our residential zoning districts as a matter of right" on the same conditions. On a lot too small for the density, the route is a rezoning or a Board of Adjustment variance, not a use permit.

Neither unit is restricted to family members or owners, and the code's definition of a dwelling unit contemplates "owner occupancy or lease on a weekly, monthly, or longer basis". The city code has no short-term rental registration or license (a code-wide search found none), and Neb. Rev. Stat. 18-1758 bars cities from prohibiting short-term rentals. Chapter 23's 4 percent hotel occupation tax reaches facilities offering sleeping accommodations for payment, including a "tourist home" and "bed and breakfast", for stays of 30 days or less, which may cover nightly rental of a unit. A no-kitchen guest building or accessory living quarters may not be rented. Selling the second dwelling separately requires a lot split meeting the subdivision rules.