ADU rules in South Sioux City

South Sioux City's Uniform Zoning Code (Chapter 130, adopted 1999) has no accessory dwelling unit, guest house or second-dwelling use. The R, Division 1 single-family districts (R-1a to R-1d) allow only 'any one-family dwelling including private garages which are accessory to the residence', and accessory buildings are defined as incidental structures 'such as a detached garage'; a detached private garage may only store vehicles. A second detached home on one lot appears only as the 'planned group dwelling' (two or more detached dwelling buildings on one lot in single ownership), a by-right use in the multifamily R, Division 3 districts, subject to their 8 or 12 units per acre density caps.

There is no ADU, but a second unit inside or attached to a house is possible as a two-family dwelling (duplex), which is a by-right use in the R, Division 2 districts (R-2a, R-2b) and every R, Division 3 district, and in the R-42R rural residential subdivision district. Table 5-A gates it by lot size and density: two-family lots need at least 10,000 sq ft (single-family lots may be 6,200 sq ft), and the density caps of 4 (R-2a), 6 (R-2b), 8 (R-3a) and 12 (R-3b) units per acre imply roughly 21,780, 14,520, 10,890 and 10,000 sq ft for two units. The R-1 single-family districts allow one dwelling only.

Because the code has no ADU, it sets no ADU floor-area cap. A duplex unit is limited only by the district's setbacks, lot coverage and height in Table 5-A (30 ft and three stories in R-1 and R-2, 35 ft in R-3). Accessory buildings may not exceed the main building's area or height without council approval, and a detached private garage is capped at 1,000 sq ft, but neither may be lived in.

Nothing in Chapter 130 requires the owner to live on a two-family or planned group dwelling lot, and the rental license program in Chapter 18 has no owner-occupancy test. There is no ADU standard that could carry one.

The Off Street Parking Schedule (Table 8-A) requires 2 spaces per dwelling unit for single-family dwellings and 2.5 per unit for multi-family; a duplex is not listed separately, so the 2-per-unit row is the likely reading, and combined uses on a lot sum their requirements. Spaces must be hard surfaced. The city council may approve less parking when the applicant shows the requirement exceeds any reasonable likely need.

Where a second unit is allowed at all (a duplex in R-2 or R-3, or a planned group dwelling in R-3), it is a by-right use needing only a building permit and zoning compliance. There is no conditional-use route for a second unit in the R-1 single-family districts; the R-zone conditional use list (city council exceptions after Planning Commission and council hearings) does not include one. In C zones, R-district uses need a council conditional use permit.

Every rental dwelling in the city and its extraterritorial zoning area needs a rental license under the Rental Inspection Program, renewed each February 28 after inspection against the International Property Maintenance Code. The zoning code has no short-term rental provision; a bed and breakfast (five or fewer guestrooms for short-term lodging) is a council conditional use in R zones. State law (Neb. Rev. Stat. 18-1758) bars a city from prohibiting short-term rentals and allows only health-and-safety regulation.