ADU rules in Shawnee

Shawnee's 2024 Unified Development Code lists Accessory Dwelling Unit as an accessory use permitted by right in R-1 (Low Density), R-2 (Medium Density), R-3 (High Density) and the Downtown Transition (DT-T) subdistrict, and by conditional use permit in TA (Transitional Agriculture), MU (Mixed Use) and the Twin Lakes Residential (TL-R) subdistrict. The definition covers a unit 'located in a detached accessory building, such as carriage houses', and the use standards set separate footprint caps for single-story and two-story detached ADUs. One ADU per lot, only with a single-family house, and only in the rear yard.

The UDC defines an accessory dwelling unit as 'an additional dwelling unit integrated within a single-family dwelling, or located in a detached accessory building', so an internal or attached unit is the same listed use with the same district map: by right in R-1, R-2, R-3 and DT-T, by conditional use permit in TA, MU and TL-R. The same standards apply (owner residency, recorded covenant, 900 sq ft living-space cap, matching design, one parking space), and the rear-yard location rule in §22-205.E.1.d is written for every ADU.

Every ADU's living space is capped at 900 square feet. A detached ADU's footprint is further limited to 50 percent of the principal structure's first-floor area for a single-story unit, or 40 percent for a two-story unit, so on a smaller house the percentage cap governs. The general accessory-building rules also apply: detached accessory buildings may not exceed 50 percent of the principal structure's floor area, combined building area may not exceed the district's lot coverage, height is limited to 18 feet, and setbacks are 5 feet from side and 10 feet from rear lot lines.

The property owner must live in either the principal house or the ADU, and an instrument must be recorded with the county clerk covenanting that the structure is established as an ADU and may only be used under those conditions, so the requirement runs with the property rather than ending at permit issuance. Oklahoma has no state law limiting owner-occupancy rules.

The ADU must provide at least one off-street parking space, matching the use table's 1/DU ratio for the Accessory Dwelling Unit row. A separate driveway giving the ADU exclusive access from a road is not allowed unless the director approves it for problematic, lot-specific circumstances. No state parking preemption applies.

In R-1, R-2, R-3 and DT-T the use table marks ADUs 'P' (permitted by right, subject to the use-specific standards), so a building permit is the review. In TA, MU and TL-R the table marks them 'C', which requires a conditional use permit: one public hearing, a planning commission recommendation, and a final decision by the city commission by ordinance, with notice to owners within 300 feet. Most in-town single-family lots are zoned R-1 or R-2.

The code does not bar renting the ADU long term, but the owner must live in either the house or the ADU, so only one of the two units can be rented, and the recorded covenant ties the ADU to these conditions. A short-term rental (30 days or less) is a conditional use in TA, R-1, R-2, R-3, MU, DT and TL and needs a city commission conditional use permit before an annual, non-transferable license from the community development department, with an annual inspection, state tax permits, occupancy limited to the number of beds and no events. Short-term rental is barred in any part of the property not approved for residential occupancy (sheds, garages, RVs). The code has no express ban on selling the ADU separately, but only one ADU is allowed per lot with a single-family house.