Compare ADU rules across Nebraska

There is no attached or internal ADU use, but a Duplex (two dwelling units within a single building on one lot) is permitted by right in the R-3 Urban Family Residential, R-4 Multiple-Family, RC Residential-Commercial and O Office districts, so a house there can be converted to or built as two units if the lot meets the site area per unit (3,000 sq ft per unit in R-3, 2,750 in R-4, 2,500 in RC and O). Duplexes are not allowed at all in the AG, RR, R-1 and R-2 districts, which cover most single-family neighborhoods, so an internal second unit is unavailable there.

Ordinance read October 2026

In the single-family districts (RS-120, RS-84, RS-72, RE, RA) a single-family dwelling is defined as a building with one dwelling unit, so no internal or attached second unit is allowed. The only route to a second attached unit is a two-family dwelling (duplex), a permitted use by right in RD-60 on lots of at least 12,000 sq ft and 80 ft wide, and in RG-50, RG-28, RG-20 and RG-8 on lots of at least 10,000 sq ft. That is a duplex conversion or build, not an accessory unit, and most single-family lots in those districts are 5,000 to 6,000 sq ft.

Ordinance read October 2026

Columbus has no accessory dwelling unit use. A second home on a lot is the Two-Family Residential use, which CLDO §3-4(b) defines to include 'two detached single-family units on a single lot'. Table 4-3 permits that use by right only in R-2 (Two-Family), R-3 (Multiple-Family), O (Office) and UC (Urban Commercial), and by special permit in LC, B-1 and B-2; it is not listed at all in AG, RR, R-1 (Single-Family) or NTR. An owner in the ordinary R-1 district would have to rezone to R-2 first, as several 2026 applicants did.

Ordinance read October 2026

An attached second unit (a duplex conversion, or a two-unit townhouse) falls under the same Two-Family Residential use in CLDO §3-4(b), so it follows the same district gate: by right in R-2, R-3, O and UC (R-2 allows townhouses only as two-unit townhouses), by special permit in LC, B-1 and B-2, and not allowed in AG, RR, R-1 or NTR. The code has no internal or basement accessory apartment use, and the residential accessory-use list in §6-8(a) contains no dwelling.

Ordinance read October 2026

In R-2, R-3, O and UC the Two-Family use is permitted by right: the Building Official issues a building permit after administrative site plan review (§12-2 requires site plan review for all uses before a building permit; §12-6(b)). In LC, B-1 and B-2 it needs a special use permit under §12-3, which goes to a Planning Commission hearing and a discretionary City Council decision. In R-1, RR and AG the use is not available without rezoning, which is a legislative City Council action.

Ordinance read October 2026

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.

Ordinance read October 2026

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.

Ordinance read October 2026

There is no attached, basement or internal accessory apartment use. The only way to put a second unit inside or onto a house is to make it a two-family dwelling ('a building designed or used exclusively for the occupancy of two families living independently of each other and having separate kitchen and toilet facilities for each family'), which is a permitted use by right in R-2 Medium Density (§5.10.2), R-3 High Density (§5.11.2, restated by Ord. No. 2191 of 12-16-2025) and R-4 Highest Density (§5.11A.2, restated by Ord. No. 2208 of August 2026), and in the MUC district. The duplex must meet the district's two-family lot rules: 12,000 sq ft and 80 ft wide in R-2, 10,000 sq ft and 80 ft in R-3. R-1 Low Density, the main single-family district, and RE, RE-A, TA and AG permit only single family dwellings, so no second unit is possible there without a rezoning.

Ordinance read October 2026

Hastings allows a detached accessory dwelling only in the A Agricultural district, and only with a conditional use permit; Table 200-1 shows no entry for "Detached Dwelling, Accessory" in R-1, R-1A, R-1S, R-2, R-3 or any business or industrial district. Under §54-304(9) the lot must be at least five acres, the unit may house only the owner's parents or children, it may not be a mobile home, and it must share utility services with the main house. The A district is mostly the two-mile extraterritorial ring outside the city limits, so in practice no detached ADU is possible on an ordinary city lot.

Ordinance read October 2026

The code has no attached or internal accessory dwelling use. The only route to a second unit inside or attached to a house is a two-unit building: the "Semi-attached dwelling (duplex)" use is permitted by right in R-2, R-3, C-O, C-1 and C-3 but not in the R-1, R-1A or R-1S single-family districts. In R-2 a two-family dwelling has its own lot standard (3,500 sq ft area and 35 ft width in the §54-205 table) and must meet the district's yards and 40 percent lot coverage.

Ordinance read October 2026

An accessory detached dwelling needs a conditional use permit: the Planning Commission holds a public hearing and recommends, and the City Council decides after its own public hearing (Table 200-1 footnote 2: "discretionary review by planning commission and city council"). Applications are due at Development Services four weeks before the commission's monthly meeting, with a site plan, building plans and a narrative, and a building permit follows. A duplex in R-2 or R-3 is a by-right use needing only a building permit, but that is a two-unit building, not an ADU.

Ordinance read October 2026

There is no attached or basement ADU either, but a second unit inside a house is lawful where the district permits a duplex, defined as 'two (2) dwelling units, each occupied by one (1) family within a single building' (Sec. 13-104(B)). Table 14-1 lists Duplex as permitted by right in R-1D, R-2, R-3, R-4, RM, UC, C-O, C-1, C-2, CBD and C-3, and not at all in AG, RR-1, RR-2 or R-1, the low-density single-family district. The lot must also meet the duplex site rules: in R-2 a conventional duplex lot needs 6,000 sq ft, 3,000 sq ft of site area per unit and 70 ft of width (Sec. 20-102); in R-1D (created by Ord. No. 8660 in January 2024) the cap is 12 units per acre with a 60 ft minimum lot width (Sec. 19-102). A house in R-1 cannot add a second unit without a rezoning.

Ordinance read October 2026

There is no ADU permit. Where a duplex is listed with a 'P' (R-1D, R-2, R-3, R-4, RM, UC, C-O, C-1, C-2, CBD, C-3), Sec. 14-112(A) makes it a use 'permitted subject to issuance of a building permit by the Building Official', with no hearing. In AG, RR-1, RR-2 and R-1 the cell is blank ('Use not permitted in zoning district'), so there is no conditional-use route and the only path is a rezoning or planned development approved by the Planning Commission and City Council. A detached living unit has no route in any district (Sec. 47-105(A)(1)(j)).

Ordinance read October 2026

There is no attached, basement or internal accessory apartment use. The only lawful way to put a second unit inside or onto a house is to make it a two-family dwelling (duplex), which the R-2 Two-Family Residential district permits by right (§5.07.02.03) on a lot of at least 10,000 sq ft and 100 ft wide with 30 ft front and rear and 10 ft side setbacks (§5.07.05.01). R-1, the city's main single-family district, permits single-family dwellings only, and the R-3 and R-4 use lists name townhouses, condominiums and multiple-family dwellings rather than two-family dwellings. The value is 'conditional' because the route exists only in R-2 and only on lots that meet the duplex size standard.

Ordinance read October 2026

A detached accessory dwelling unit is allowed only in the AG Agricultural district, only by special permit, and only on a lot of 20 acres or more (abutting section-line and half-section-line road right-of-way counts toward the area). One ADU per lot; a detached unit must sit within 200 feet of the main house and no closer to the street than the house. No other county district (AGR, R, B and the rest) lists an ADU, so acreage lots zoned AGR cannot add one under the county regulations.

Ordinance read October 2026

The county definition covers a "subordinate building or portion of the main building," so an attached or internal unit (basement apartment, addition) goes through the same AG-only special permit with the same 20-acre minimum, size cap and owner-occupancy rule as a detached one. Outside AG there is no route for a second unit inside the house.

Ordinance read October 2026

An ADU needs a special permit, which requires a public hearing before the Lincoln-Lancaster County Planning Commission; the Commission's action may be appealed to the County Board. The Commission weighs neighborhood character, traffic, utilities and the Comprehensive Plan and may add conditions. The county fee for a special permit on more than 1 acre is $1,204 (Resolution R-26-0070, effective 10-1-2026). A building permit follows, after the deed restriction is recorded.

Ordinance read October 2026

Lexington's zoning ordinance has no accessory dwelling unit use. In the R-1, R-2, R-3 and R-4 residential districts a lot may hold only one principal building (§4.06.01), R-1 permits 'One single-family dwelling per zone lot' (§5.07.02), and the only lodging allowed in a detached outbuilding is 'accessory living quarters' for temporary guests with no kitchen that may not be rented or used as a separate dwelling unit, which is not an ADU. The one route to a second detached home is in the A-1 Agricultural and A-2 Transitional Agriculture districts, where 'One additional single-family dwelling for the purpose of housing relatives or agricultural workers' is a conditional use (§5.05.03(12), §5.06.03(8)) approved by the City Council after Planning Commission and Council hearings. Those districts require 10-acre residential lots and lie mostly in the two-mile extraterritorial ring, so on an ordinary city lot a backyard cottage is not possible.

Ordinance read October 2026

There is no attached, basement or internal ADU use either. The only lawful way to put a second unit inside or onto a house is a two-family dwelling (duplex), defined as a building 'designed or used exclusively for the occupancy of two families living independently of each other and having separate kitchen and toilet facilities for each family' (§2.02). Two-family dwellings are permitted by right in R-2 (§5.08.02(3)) and R-3 (§5.09.02(6)), but not in R-1 Single-Family Residential, R-4 or the agricultural districts. The lot must meet the duplex standard: 10,890 sq ft and 75 ft of width in R-2, or 7,260 sq ft and 75 ft in R-3, against 7,000 sq ft (R-2) for a single-family home.

Ordinance read October 2026

The route depends on the form. The A-1/A-2 additional single-family dwelling is a conditional use: under §§6.01 to 6.05 the Planning Commission holds a public hearing and recommends, the City Council holds its own hearing and grants or denies by majority vote, and an approval takes the form of a signed conditional use agreement that lapses if the use does not start within 12 months. A duplex in R-2 or R-3 is a permitted use that needs only a building permit and certificate of occupancy (§4.13.03 bars using any accessory building as a dwelling without a certificate of occupancy).

Ordinance read October 2026

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).

Ordinance read October 2026

A detached ADU is a permitted (P) use in the R-L, R-1, R-2 and R-3 districts under the Residential Use Table, added by Ord. 4092 in June 2022, and is not allowed in R-M. The catch is a lot-area gate: § 156.311(A) requires the lot to meet the district's minimum lot area for a two-family dwelling, which is 6,000 sq ft in R-2 (against 5,000 for a house) and 4,000 sq ft in R-3 (the same as a house). R-1 and R-L list no two-family lot area at all (duplexes are conditional in R-1 and not allowed in R-L), so staff must read the gate against the 9,000 sq ft R-1 'conditional uses' figure or the 12,000 sq ft R-L figure. A detached ADU must also sit at least 50 feet back from the front lot line.

Ordinance read October 2026

The code's ADU definition covers 'an attached or detached extension to an existing single-family structure' with its own entrance, kitchen, sleeping area and full bath, so an attached ADU follows the same rule as a detached one: permitted in R-L, R-1, R-2 and R-3, but only on a lot that meets the district's two-family minimum lot area under § 156.311(A). In R-3 that gate matches the 4,000 sq ft house minimum; in R-2 it is 6,000 sq ft; R-1 and R-L carry no two-family figure, so the larger conditional-use lot sizes are the likely yardstick. A full duplex is a separate route, permitted in R-2 and R-3 and a conditional use in R-1.

Ordinance read October 2026

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.

Ordinance read October 2026

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.

Ordinance read October 2026

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.

Ordinance read October 2026

A detached ADU is allowed only as a "secondary residence in an accessory structure, such as a caretaker's residence, guest home, granny flat or hired-hand quarters," and only with a special use permit, which Papillion's code lists as a permitted accessory use to any residential use (§ 205-208(B)(6)). The special use permit is a discretionary approval: a Planning Commission public hearing and recommendation, then a City Council public hearing and majority vote (§ 205-302). Separately, the Two-family residential use (two dwelling units on one lot, each in a separate building) is permitted by right in R-3, R-4 and MH and by special permit in R-2 under Table 205-38, but it is a two-principal-dwelling use with a 50-foot frontage minimum and rear-placement rules (§ 205-200(C)), not an accessory unit, and it is not available in AG, RE or R-1.

Ordinance read October 2026

The code has no attached or interior ADU route. The secondary-residence allowance in § 205-208(B)(6) is limited to an "accessory structure," and an accessory building physically attached to the house is treated as part of the principal building (§ 205-220(A)(10)). Single-family residential is defined as "one dwelling unit, occupied by one family" (§ 205-17(A)), so a second unit inside or attached to a house is a Duplex, which Table 205-38 permits by right only in R-3 and R-4 and by special permit in R-2, subject to the duplex lot standards (for example a 12,000 sq ft minimum lot in R-2 and 10,000 sq ft in R-3); it is not allowed in AG, RE or R-1. A pending rewrite (Ord. 2093) would allow one interior ADU in every single-family residence, but the Council tabled it on 8-18-2026.

Ordinance read October 2026

A secondary residence needs a special use permit, which the code describes as "public review and discretionary City Council approval": the Planning Commission holds a public hearing and recommends, and the City Council holds its own public hearing and votes (§ 205-302(A), (B) and (D)). The application requires a site plan, a title-company certified list of owners within 300 feet with mailing labels, and a fee of $300 (one acre or less) or $500 (over one acre). A permit lapses if not used within two years and can be revoked for violating its conditions (§ 205-302(G)). A building permit is also required. The by-right Duplex and Two-family uses in R-3 and R-4 are the only routes to a second unit that skip the hearing.

Ordinance read October 2026

The Sarpy County Zoning Regulations have no accessory dwelling unit use. A second detached house is allowed by right only through Section 1.7.2, which lets more than one single-family residence stand on one lot if the lot could be split into separate lots that each fully conform, so the lot must hold at least twice the district minimum (2 acres in RE1, 4 acres in RE2, 10 acres in AGR, 20,000 sq ft in RS-100, 14,400 sq ft in RS-72). In AG and AGD, farm dwellings for the owner's family, tenants and employees are a principal permitted use. A detached guest house is allowed only without a kitchen and may not be rented or used as a separate dwelling unit, so it is not an ADU.

Ordinance read October 2026

The regulations have no accessory dwelling use, and the only route to a second unit inside or attached to a house is a two-family dwelling, which is a permitted use only in RD-50 and the RG districts (10,000 sq ft minimum lot for a two-family dwelling). It is not allowed in the AG, AGD, AGR, RE or RS districts, which cover most unincorporated single-family land. A single-family dwelling is defined as having kitchen and toilet facilities for only one family, so adding a second kitchen unit on an ordinary single-family lot is not allowed.

Ordinance read October 2026

There is no ADU category, but a house can hold a second, independent unit as a two-family dwelling (a duplex, defined as one building under one roof for two families living independently). Two-family dwellings are a principal permitted use in R-1a Medium Density Residential and R-4 Heavy Density Residential, and a conditional use (formerly special permit use) in R-1 Low Density Residential. R-1b, R-6, AR and A do not list them. In R-1a a two-family dwelling needs a 7,000 sq ft lot that is 70 ft wide, against 5,500 sq ft for a single-family house.

Ordinance read October 2026

In R-1a and R-4 a two-family dwelling is a principal permitted use that needs only a building permit and zoning review. In R-1 it is a conditional use: the Planning Commission holds a noticed public hearing under Neb. Rev. Stat. 19-904 and 19-905, makes written findings and may attach conditions. Ord. 4366 (passed 2-2-2026) renamed the old special permit to the conditional use permit and added an expiration for permits that are not used, but kept the Planning Commission hearing.

Ordinance read October 2026

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.

Ordinance read October 2026

The code never names an accessory dwelling unit, but the "R" Single-Family district lists "Single-family ... and two-family dwellings" as a permitted use (Art. VII Sec. 3(1)), as do R-2 and R-3. A homeowner can therefore add a second unit inside or attached to the house only by making it a two-family dwelling, which in "R" needs a lot of at least 5,000 sq ft per family (10,000 sq ft) and in R-2 at least 3,000 sq ft per family (6,000 sq ft). Many older 7,200 sq ft "R" lots fall short. R-2's roomer rule allows renting up to two sleeping rooms but bars separate culinary accommodations, so it is not an ADU route.

Ordinance read October 2026