ADU rules in Henderson

Henderson's zoning regulations have no accessory dwelling unit, accessory apartment, garage apartment or guest house use in any district. Section 4.21 allows no more than one principal building per lot except in a multi-family development, group home or PUD, and a 'lot' is defined around one principal building plus its accessory buildings, so a second house in the backyard is not allowed. The R-1 and R-5 single-family districts permit only single-family detached dwellings plus customary accessory buildings 'not involving any business', and the dwelling-unit definition (complete living, sleeping, cooking and sanitation facilities) means a garage or shed fitted out as a home would be a second dwelling unit rather than an accessory building. Planning staff told the Planning Commission on September 1, 2026 that an ADU ordinance is being researched but has not been drafted.

No district allows an accessory apartment inside a single-family home. The only route to a second unit in a house is a two-family dwelling (duplex), which §4.06 permits by right in R-2, R-3 and R-4, in a PUD and in the Audubon Residential district, subject to the district's two-family minimums: 10,000 sq ft and 75 ft of width in R-2, 9,000 sq ft in R-3 and 8,000 sq ft in R-4. The R-1 and R-5 single-family districts do not allow two-family dwellings, so a lot there would need a rezoning (Planning Commission hearing and City Commission ordinance).

Because the ordinance has no ADU use, it sets no ADU floor-area cap. A two-family dwelling follows the Schedule of Regulations: in R-2 a 10,000 sq ft minimum lot, 75 ft width, 25 ft front and rear yards, 8 ft side yards, 40 percent lot coverage and a 30 ft height limit. Residential accessory buildings may not exceed one story or 14 ft (nor the height of the house), may cover no more than 25 percent of a non-required yard, and together may not exceed the floor area of the principal building; a lot may have one detached garage or carport and two other accessory buildings.

No owner-occupancy rule applies to the only available route, a two-family dwelling in R-2, R-3, R-4, PUD or Audubon Residential; both units may be rented. The ordinance's owner-occupancy language appears only for bed and breakfast inns and for the single dwelling a commercial owner-operator may add by conditional use in the business districts.

The off-street parking schedule requires two spaces for each unit of a single- or two-family dwelling, so a duplex needs four in total, on the same lot as a garage or a hard-surfaced strip and apron connected to a street or alley. A parking amendment to §9.01 passed the Planning Commission on October 6, 2026 and had its first City Commission reading on October 13, 2026; the draft table in that packet keeps two spaces per single- or two-family dwelling unit.

Where a two-family dwelling is a permitted use (R-2, R-3, R-4, Audubon Residential), it needs a building permit from the enforcement officer with no Board of Zoning Adjustment hearing; a PUD needs Planning Commission approval of the development plan. Getting an R-1 or R-5 lot into a two-family district is a zoning map amendment with a Planning Commission hearing and City Commission ordinance. There is no conditional-use route for a second unit in the single-family districts.

The zoning ordinance does not regulate short-term rentals: a 2024 short-term rental zoning amendment recommended by the Planning Commission was pulled by the City Commission and never adopted, and the codified text through Ord. No. 39-25 contains no short-term rental use. Rentals of 30 days or more are not restricted by zoning. The city's 3 percent transient room tax (Code §21-110) covers accommodations regularly furnished to transients and the platforms that broker them, and §21-115 exempts short-term rentals supplied for 30 days or more (Ord. No. 48-24).