ADU rules in Norman

A detached ADU is a listed by-right use only in the A-1, A-2, RE, R-1 and R-1-A districts; the ADU definition itself says an ADU 'may be utilized only within' those five districts, and R-2, RM-2 and R-3 expressly do not inherit the R-1 ADU use. Inside those districts it is routine: one ADU per lot, on the same parcel as the house, no further forward than the principal structure, meeting the district's accessory-building setbacks (in R-1, 5 feet from side lot lines and 1 foot from the rear easement or alley line). The two-family and multifamily districts allow a 'single-family dwelling and a garage apartment' instead, a separately defined use.

The ADU definition covers a unit 'attached to the principal dwelling by a common wall or roof', so internal or attached ADUs follow the same district list as detached ones: by right in A-1, A-2, RE, R-1 and R-1-A, not available as an ADU elsewhere. In R-2, RM-2 and R-3 the equivalent second-unit routes are a duplex or a single-family dwelling with a garage apartment (7,000 sq ft minimum lot).

In R-1 (and R-1-A, which adopts every R-1 use) the listed use is 'One accessory dwelling unit with a total area of no more than six hundred fifty square feet'; the city's 2026 FAQ reads this as total living area across all floors. In the agricultural and estate districts there is no numeric cap, only the definition's requirement that the ADU be 'clearly subordinate to the principal dwelling unit in size, including height', plus rear-yard coverage caps (accessory buildings including ADUs may cover no more than 20% of the rear yard in A-1 and A-2, 10% in the Ten Mile Flat area). In R-1 an accessory building, including an ADU, may not exceed a 10-foot wall height unless side and rear setbacks grow a foot per extra foot, and never above the principal building.

Neither the ADU definition nor the district use lists, setbacks or parking table contain any owner-residency condition for an ADU; the code's only 'owner shall reside on-premises' rules are for Type I and Type II bed and breakfasts. The city's ADU FAQ lists no owner-occupancy requirement either. Oklahoma has no statute on the point.

Ordinance O-2324-51 (adopted 5-28-2024) amended the parking table 'to remove parking requirements for accessory dwelling units where allowed': single and two-family dwellings now need '2 per primary du, ADU more than 650 sq ft in area (where allowed), and garage apartment (where allowed)'. Because R-1 and R-1-A cap ADUs at 650 sq ft, no ADU there needs a space; ADUs built before 4-25-2024 without parking are not nonconforming for that reason. The city FAQ says parking applies to ADUs 'of 650 square feet or more', slightly looser than the code's 'more than 650'.

In the five eligible districts the ADU is a listed permitted use ('Uses permitted'), not a special use under §36-560, so approval is a building permit plus related mechanical, electrical and plumbing permits applied for through the city's online portal under the 'Accessory Dwelling Unit' construction permit type. The FAQ says only state- and city-licensed contractors can pull these permits and a site plan must show sewer and water service. A second unit in R-2, RM-2 or R-3 (garage apartment or duplex) is also a by-right use; anything else needs a rezoning or a PUD.

Nothing in Chapter 36 limits long-term rental of an ADU or requires either unit to be owner-occupied. Short-term rentals (30 days or less) are a listed use in A-1, A-2, RE and R-1 but need an annual license from the City Clerk (annual inspection, neighbor notice, local contact, at most four licenses per applicant without a special use, transient guest tax now 10%). §36-554 bars short-term rentals 'in an accessory structure (e.g., shed, garage, etc.)', and §36-101 says 'accessory' includes an ADU where the district allows one, while the licensing definition in §20-2701 covers any 'existing or otherwise permitted dwelling structure'; whether a permitted ADU can be licensed is not settled in the text, so confirm with Planning ((405) 366-5318) before listing one. No separate-sale provision exists, but the ADU must sit on the same parcel, is addressed as 'Unit 2' and cannot have its own water meter.