ADU rules in Omaha

Omaha allows a detached ADU (a standalone structure with no more than one dwelling unit) on any site with an approved residential use, but the route depends on the zoning district. In the ordinary single-family districts (DR and R1 through R4), as well as AG and the LO, GO, LC, CC and GC office and commercial districts, a detached ADU needs a conditional use permit from the Planning Board after a public hearing. It is allowed by right in R5, R-WRN, R6, R7, R8, MH, NBD, CBD, DS and TOD. One ADU is allowed per site, setback at least 20 feet behind the front plane of the main house.

Attached ADUs (connected to the house with their own foundation) and internal ADUs (basement or attic units with no separate foundation) follow the same district split as detached units. They need a Planning Board conditional use permit in AG, DR, R1 through R4 and the office and commercial districts, and are permitted by right in R5, R-WRN, R6, R7, R8, MH, NBD, CBD, DS and TOD. Only one ADU of any type is allowed per site.

The 2024 ADU standards in §55-763(a) set no square-footage limit: the ADU must fit the base district's site development regulations, with a 15 percent bonus to maximum building and impervious coverage for ADU improvements, and the largest building on the site is treated as the primary dwelling. A detached ADU may sit 5 feet from the interior side and 8 feet from the rear lot line (3 feet where no utility easement exists); using those reduced setbacks caps its height at 16 feet, otherwise the base district height applies (35 feet in R3, for example). The R-WRN walkable residential district keeps its own rule that an accessory dwelling unit may not exceed 500 square feet of gross floor area and must sit at the rear of the site. The 750 sq ft or 50 percent cap reported in the press came from the 2020 TOD-area ADU code, which Ord. No. 43728 repealed in 2024.

The current ADU standards contain no owner-occupancy requirement. The 2020 ADU code required the owner to live in the main house or the ADU as a legal and permanent residence, but Ord. No. 43728 (passed 3-5-2024) struck that requirement along with the old accessory-apartment rules, which also required owner occupancy. Nebraska has no state rule on the subject.

Section 55-763(a)(5)f states that no additional on-site parking is required for an ADU. The site may have only one driveway per street frontage serving both the ADU and the main house. The 2020 code's two-space requirement for the combined ADU and main house was repealed in 2024.

In R5, R-WRN, R6, R7, R8, MH, NBD, CBD, DS and TOD an ADU is a permitted use needing only a building permit and staff review. In AG, DR, R1 through R4 (most single-family neighborhoods) and the LO, GO, LC, CC and GC districts it requires a conditional use permit under §55-883: the Planning Board holds a public hearing and makes discretionary findings, the applicant must certify contact with adjoining owners and registered neighborhood associations, and a denial can be appealed to the City Council. The city reported 5 by-right ADU building permits and 4 Planning Board conditional use permits in 2024.

Either unit may be rented, but if any residential unit on the site is offered for rent, the property must be registered under the city's rental registration and inspection program (§48-204), which covers leases longer than 30 days. The ADU cannot be sold separately from the main house. In DR through R4, combined occupancy of both units may not exceed three unrelated persons. Omaha's 'Short Term Rental' article (§§43-317 to 43-333) licenses only bed and breakfasts (rooms with owner-provided meals), and stays of 30 days or less owe the city hotel occupation tax (Chapter 19, Article XV); nothing in the ADU section bars nightly rental, and Neb. Rev. Stat. 18-1758 prohibits a city from banning short-term rentals.