ADU rules in Owensboro

Since Ordinance 16-2026 (second reading and adoption 8-18-2026), a detached accessory dwelling unit is a conditional use in the A-R, A-U, R-1A, R-1B, R-1C, R-1T and R-4DT zones, so every detached unit needs a conditional use permit from the Owensboro Metropolitan Board of Adjustment. It must sit in a side or rear yard, meet principal-structure setbacks and the Kentucky Building Code, and only one ADU is allowed per parcel. The multi-family zones (R-2MF, R-3MF) are not listed. Before the 2026 amendment the ordinance allowed accessory dwellings only above or behind business, office and industrial uses.

An attached accessory dwelling unit is a principally permitted use (P/2A) in the A-R, A-U, R-1A, R-1B, R-1C, R-1T and R-4DT zones under Ordinance 16-2026, subject to the /2A conditions: one per parcel, owner residing on site, 50 percent of the principal structure's footprint, entrance on the side or rear facade, principal-structure setbacks, one extra parking space, an attorney's no-covenant letter (or a plat note) and Health Department approval where on septic. In R-2MF and R-3MF a second unit is reachable through the two-family or multi-family uses instead.

Both §8.4/2A and /2D cap the ADU's floor area at fifty percent of the footprint of the principal structure; there is no fixed square-foot cap and no minimum. Attached units may not exceed the height allowed by the underlying zone, which is 36 feet in R-1A, R-1B, R-1C and R-1T (§8.5.5 to 8.5.8) and has no limit except airport zoning in A-R and A-U (§8.5.1, 8.5.2). Both types must meet the setbacks for principal structures, not the lighter accessory-building setbacks. The detached /2D list carries no explicit height line in the text read, so the zone height and any Board of Adjustment conditions govern.

Both attached (§8.4/2A(1)) and detached (§8.4/2D(1)) units require the current owner of the property to reside in either the primary dwelling or the ADU. The text is framed as a standing condition of the use (the 'current' owner), not only an at-application test. Kentucky has no state ADU law preempting owner occupancy.

Both ADU types require a minimum of one additional parking space beyond the parking required for the primary dwelling (§8.4/2A(6), /2D(6)). Article 13's parking schedule likewise lists 'Dwelling: Accessory' at one space per dwelling unit. No transit or lot-size exemption is written.

Attached ADUs are principally permitted in the agricultural and single-family zones, so they go through OMPC zoning review and a building permit with the attorney's covenant letter (and Health Department approval on septic). Detached ADUs are conditionally permitted and need a conditional use permit from the Owensboro Metropolitan Board of Adjustment after a public hearing, with septic approval required before the CUP application is filed. Under §8.2 'C' uses are 'permitted only with Board of Adjustment approval.'

The ADU conditions require the owner to live in one of the two units but say nothing against renting the other, and neither the ADU text nor Article 14 addresses short-term rental of an ADU; the zoning use closest to nightly rental is the owner-occupied bed and breakfast home, a conditional use limited to two rooms in R-1 zones. City Code §16-70.39.5 (Ord. 19-2024) requires anyone operating a short-term rental in Owensboro to register annually with the Finance Department (fine up to $500 for not registering within 60 days), and stays under 30 days owe the transient room tax. No condominium or separate-sale rule appears in the ADU text, though the one-ADU-per-parcel rule and owner-residency condition make a separate sale impractical.