Are ADUs or in-law suites allowed in Royal Oak?

Royal Oak provides a limited special-use path for senior accessory housing under § 770-71. It is not a general permission for a detached or unrestricted second dwelling. Section 770-22A(11) separately restricts combinations of utility services that make an accessory building easily convertible to habitable space.

Senior accessory housing is one additional dwelling for an elderly related person within or attached to an existing single-family dwelling. The owner must occupy the property, and the city reviews the special-use permit every two years. The unit is limited to 600 square feet, except where an existing dwelling can reasonably, conveniently and safely be converted to a slightly larger one-bedroom unit. One dedicated off-street parking space is required. All residential bulk and setback requirements apply. The owner must record a notice that the property was used for senior accessory housing and may not continue as a two-family land use.

In the One-Family Large Lot Residential (1FL) district, an existing single-family dwelling may be expanded to add a senior accessory dwelling of up to 600 square feet of usable floor area without regard to the 3,500-square-foot single-family floor-area cap. All other area and bulk requirements still apply, and the addition remains subject to § 770-71. This district-specific exception was added by Ordinance 2026-05, adopted May 18, 2026 (§ 770-35D(10)).