Cass County, MO Accessory Structures: ADU Rental Restrictions (2026)

050 of the Zoning Order defines DWELLING, TRANSITIONAL as a single-family accessory dwelling, attached or adjacent to the principal dwelling on the parcel, occupied temporarily by not more than two adult individuals who, due to human frailty, are in the care and custody of the residents of the principal residence. The definition states the intent is to accommodate transitional living needs of family members, not to provide caretaking facilities, and it directly prohibits charging rent for the unit. The unit may contain housekeeping facilities limited to a single bath and one kitchen, and it cannot have a separate mailing address from the principal residence.

030 separately caps this transitional living dwelling at nine hundred square feet and permits it only on a conforming lot zoned Agricultural, Rural Residential, or Rural-Suburban, and only through a Special Use Permit; the duration of the permit is set by the Board of Zoning Adjustment under the regulations issued by the Zoning Department. Because the county's definition ties the entire use to unpaid, family caretaking arrangements, a property owner cannot convert this accessory dwelling into a rented apartment or short-term rental without losing its transitional-dwelling status and the permit that allows it.