ADU rules in Muskogee

A detached ADU (a unit in an accessory structure on a single-family lot) is allowed only in the A-1 agricultural, R-A and R-1 districts and only through a 'special permit'; it is prohibited in every other district. The unit must be a complete housekeeping unit with kitchen and bath, only one is allowed per lot, its separate entrance must face the interior of the lot, and the structure must match the principal house's materials, roofing, roof pitch, trim and colors.

An ADU incorporated within a single-family dwelling (internal or attached) is permitted as of right with a building permit in the A-1, R-A and R-1 districts and is prohibited in all other districts. The house must be owner-occupied, the unit must have its own kitchen and bath, and only one ADU is allowed per house or lot. R-2, R-3 and R-4 allow two-family dwellings by right instead (Table 90-08(A)).

The ADU's gross floor area may not exceed 900 square feet, and a unit in an accessory structure is further capped at 40% of the rear yard, whichever is less; it may never later be enlarged beyond those limits. The unit may have only one bedroom and no more than two occupants, its footprint may not exceed the principal residence's, and the accessory structure holding it may not exceed one and a half stories or 18 feet. The ADU, house and all other structures together may not cover more than 35 percent of the lot.

Ongoing: the owner must continue to occupy one of the two units as a primary residence, except for bona fide temporary absences. Before a permit issues the owner must send a notarized letter stating so, and a buyer who wants to keep the ADU must file a new notarized letter with the Building Official within 30 days of the sale. Oklahoma has no statute preempting owner-occupancy rules.

One off-street space beyond what the principal house requires must be available to the owner-occupants and the ADU's occupants. A detached single-family house itself requires 2 spaces under Table 90-14-10, so a lot with an ADU needs 3 in total. Driveway parking counts for single-family dwellings (§90-14-08.C.2).

An internal ADU is as of right: §90-12-04.E.3.a lets the Building Inspections Department issue a building permit. A detached ADU needs a 'special permit', which the same clause also has the Building Inspections Department issue, but the zoning code never defines a special permit or a procedure for one. The use tables' 'special' uses go to Board of Adjustment special exceptions after a public hearing (§90-02-05), and Specific Use Permits (Article 23) go to the city council and do not list ADUs. Ask the Planning Department which route applies before you budget for a detached unit.

The code says ADUs 'can only be occupied by members of the principal homeowners' extended family and not as rental property', so neither long-term nor short-term rental of the ADU is allowed. Muskogee has no short-term rental ordinance or license (a Municode search for 'short-term' finds only unrelated definitions). Lodging taxes still apply under state law to any lawful lodging use.