ADU rules in Lincoln

A detached accessory dwelling is allowed with a single-family home in the R-1, R-2, R-3 and R-4 districts as a 'permitted conditional use', which in Lincoln means allowed by right when the listed conditions are met, with no hearing. Since Ord. 21860 (March 30, 2026) the lot only needs the ordinary single-family minimum lot area for its district (9,000 sq ft in R-1, 6,000 in R-2 and R-3, 5,000 in R-4) instead of the larger two-family area. A detached unit uses the accessory-building setbacks of 27.72.120 but must sit at least 60 feet back from the front lot line (corner lots excepted) and may have no windows or wall openings within 5 feet of a rear or side lot line. ADUs are not listed in AG, AGR or R-5 through R-8.

The accessory dwelling is defined as 'a subordinate building or portion of the main building', and 27.62.040(b) allows 'a single-family dwelling and an accessory dwelling' in R-1 through R-4 under the same conditions, adding that 'an attached accessory dwelling shall meet the required setbacks for the main building'. The 27.06.070 use table row is labeled 'Single-family dwelling with detached accessory dwelling', but the condition section and definition expressly cover attached and internal units. Same lot-area condition as detached: the district's single-family minimum.

The ADU's total square footage may not exceed the lesser of 40 percent of the total square footage of the main building or 800 square feet, so a 1,500 sq ft house allows 600 sq ft and the 800 sq ft cap binds only for houses of 2,000 sq ft or more. It may have no more than one bedroom. Its floor area does not count toward the accessory-building floor-area cap of Table 27.72.120(d). Ord. 21860 dropped the old height cap tied to the main building: the ADU follows the district height limit (35 feet in R-1 through R-4), or the accessory-building limit (15 feet) if it occupies the setbacks.

Ongoing requirement: the owner of the lot must reside on the property, in either the main house or the ADU. Ord. 21860 extended this to 'a person with a controlling interest or who is the beneficiary of any legal entity owning the lot', so trust- or LLC-held lots can qualify. Nebraska has no state ADU law preempting owner occupancy.

One parking stall is required for the ADU in addition to the parking required for the single-family home. The parking chapter repeats the rule: accessory dwelling units need one space per dwelling unit beyond the main use's requirement. No transit or proximity exemption is written into either section.

Lincoln lists the ADU as a 'permitted conditional use' (C in the use table), which 27.11.030 and 27.62.010 define as a use allowed in the district 'in conformance with the Chapter 27.62 conditions of approval', checked administratively with no public hearing; this differs from Lincoln's 'permitted special uses' (S), which need a special permit. In practice the ADU goes through a building permit reviewed against the 27.62.040(b) conditions. The owner must also record a deed restriction barring separate sale.

Nothing in the ADU conditions bars renting the unit long-term, but because the owner must live on the lot, one of the two units is owner-occupied. Since Ord. 21860 an ADU 'may be used as a short-term rental' (stays of 30 days or less) if the operator holds a Chapter 5.39 license and it is the only short-term rental on the premises. The STR license costs $250 a year and requires a safety self-certification and a 45-minute emergency contact; occupancy is capped at two per sleeping area, up to 12. A recorded deed restriction bars selling the ADU separately from the main house.