ADU rules in Oklahoma City

Allowed since Ord. No. 27847 (adopted May 20, 2025): a detached Accessory Dwelling (a freestanding unit, or one above or beside a detached garage) is a conditional use in R-1, R-2, R-3, R-4 and NC, but only where the parcel also sits in the Urban Medium or Urban High Land Use Typology Area of the planokc comprehensive plan, which covers the older core of the city rather than its suburban and rural fringe. In R-2, R-3, R-4 and NC the lot must be occupied by a single-family house; the lot must be at least 50 feet wide; and the unit goes in the rear yard meeting district setbacks. It is barred in the Historic Landmark Overlay and the Historic Preservation district (whose use table lists no accessory dwelling and allows one single-family dwelling per lot), and in a PUD or SPUD that does not list it; everywhere outside the UM/UH core an accessory dwelling still needs a rezoning such as a SPUD.

The same 9350.2.1 standards allow an attached unit with its own exterior entrance or an internal unit without one, under the same gates as a detached unit: R-1 (or a single-family house in R-2, R-3, R-4 or NC), inside the planokc Urban Medium or Urban High Land Use Typology Area, at least 50 feet of lot width, and outside the Historic Landmark Overlay, the HP district and PUDs or SPUDs that do not list the use. Only one accessory dwelling of any type is allowed per parcel.

Every accessory dwelling, detached, attached or internal, is capped at 950 square feet of total floor area, and only one is allowed per parcel. The zoning district's lot coverage limit (50 percent of the lot, per the city ADU page and Table 6100.2) applies to all structures including the ADU, so a large house or other outbuildings can shrink what is buildable. A detached unit may be no taller than the principal dwelling or 25 feet, whichever is less, except that a unit built above a new or existing detached garage may reach 25 feet for the whole structure regardless of the house height. A new ADU needs a lot at least 50 feet wide; there is no minimum unit size.

The adopted standards contain no owner-occupancy requirement for either the principal house or the accessory dwelling, and the signed text of Ord. No. 27847 has none either. The only residency test is for short-term rental: an accessory dwelling may be used for home sharing only when it is on the same parcel as the host's primary residence and the host occupies that residence at the time of the rental. The ADU also cannot be split off from the ownership of the principal dwelling.

One off-street space is required unless the paved street frontage measures at least 26 feet curb to curb or the ADU has 600 square feet of floor area or less; on paved streets without curbs one space is required regardless of width. New parking may not go in front of the principal dwelling, an improved alley may provide the access, and garage spaces count toward the ADU space as long as the house's own required parking is still met.

Table 6100.1 lists Accessory Dwelling as 'C' (conditional), but in Oklahoma City a conditional use is an administrative approval: the Public Works Director (staff) checks compliance with the Article IX standards and, if they are met, the use 'shall constitute a permitted use', with no hearing; discretionary uses are the separate SE (Board of Adjustment) and SP (Council) categories. 9350.2.1.C requires a building permit for a new unit or a conversion, and the owner must post a notice sign with the permit number within 30 days of filing until the certificate of occupancy issues. Sites outside the UM/UH typology areas, in the HP district or Historic Landmark Overlay, or in other zones need a rezoning (for example a SPUD, plus Historic Preservation Commission design approval in historic districts), which is a legislative hearing.

Nothing in 9350.2.1 restricts long-term rental of the ADU or the house; the unit may house one family and may not be divided from the ownership of the principal dwelling, so it cannot be sold separately. Rentals under 30 consecutive days are allowed in an ADU only when it sits on the same parcel as the host's primary residence and the host occupies that residence at the time of the rental, and 9350.2.1.G.2 additionally requires a Board of Adjustment special exception under 9350.38.1.E. Each rented dwelling unit needs its own annual home sharing license from the Supervisor of Licenses (fee $120.00 for July 2026 to June 2027 per the city's license page), special exceptions run up to three years and are capped at the greater of one per block or 10 percent of the block's dwelling units, and the special exception requires one off-street space per four occupants. Hotel tax of 5.5 percent applies to home sharing rentals of two or more bedrooms per the city's license page.