ADU rules in Norfolk

A detached accessory dwelling unit is a permitted use on single-family detached lots in the A, R-R, S-R, R-1, R-2, R-3 and R-O districts, each of which lists 'Accessory dwelling units, as per Sec. 27-287(b)' among its permitted uses. It is not listed in R-M (mobile home), R-T (tiny house), office, commercial or industrial districts. Only one detached ADU is allowed per lot, it must sit behind the rear building line of the house on a permanent perimeter foundation, and it may come within 7 feet of the rear lot line but never into an easement. Ord. No. 5799 (9-6-22) added the current rules.

Norfolk's code has no attached or internal ADU: the definition and every standard in Sec. 27-287(b) cover only a detached unit, and Sec. 27-287(a)(4) bars using other accessory buildings as dwellings. Adding a second unit inside or onto a house is possible only as a duplex, which is a permitted use in R-1, R-2, R-3 and R-O (in R-1 a duplex needs a 6,000 sq ft lot, 3,000 sq ft per unit), and is not available in the A, R-R or S-R districts. A duplex carries none of the ADU rules (no owner-occupancy rule, but normal parking at two spaces per unit).

The ADU may not exceed the lesser of 60 percent of the total square footage of the main building or 864 sq ft. The ADU plus all other accessory buildings must also stay within the district's accessory-building allowance (in R-1, the greater of 8 percent of the lot, 864 sq ft, or 400 sq ft per dwelling unit, never more than 2,000 sq ft in total; in S-R, the smaller of 5 percent of the lot or 2,500 sq ft). Sec. 27-287(b) sets no separate ADU height, so the district's 35-foot maximum height applies.

The lot owner must live on the property, either in the main house or in the ADU. The requirement is ongoing, not only at application, and the Sec. 27-2 definition repeats it. Nebraska has no state law limiting owner-occupancy rules.

No parking space is required for the ADU. However, existing required parking for the house (two spaces per single-family dwelling) may not be removed to build the ADU unless it is replaced elsewhere on the lot in conformance with the code.

A detached ADU is a listed permitted use in A, R-R, S-R, R-1, R-2, R-3 and R-O, so it needs only the ordinary permit that Sec. 27-22 requires before any building is built, reviewed by the Planning and Development Department. No public hearing is involved. A conditional use permit is needed only to depart from a standard the code lets a CUP modify, such as the architectural compatibility rule for accessory buildings.

The zoning code does not bar renting the ADU or the house, but the owner must live in one of the two units. Short-term rentals are allowed in A, R-R, S-R, R-1, R-2, R-3, R-M, R-T, R-O and C-2 under Sec. 27-284, but the operator needs an annual license under Chapter 13, Article XVII. The license requires an inspection by a city inspector for smoke and CO alarms, egress and sanitation, and occupancy is capped at two persons per sleeping area (maximum 12). The ADU must share utility connections with the main house (no separate meters).