Kirkwood, MO Accessory Structures: ADU Owner Occupancy (2026)

Kirkwood added accessory dwelling units to its Zoning and Subdivision Code as a limited form of gentle density, but it paired the allowance with an owner-occupancy condition rather than opening ADUs to pure rental investment. Section 25-45(b)(11) states that the owner of the lot shall reside in either the principal dwelling or accessory dwelling unit as long as both dwelling units are occupied as residences. The condition is tied to occupancy of both units at once: if only the ADU is rented and the principal house sits vacant, or vice versa, the rule still requires the owner to be living in one of the two.

The requirement sits alongside the rest of § 25-45(b)'s ADU package: only one ADU is permitted per lot (b)(7), the lot must be at least 15,000 square feet (b)(8), the unit is capped at 750 square feet and two bedrooms (b)(9), and an extra off-street parking space is required beyond what § 25-65 already demands for the principal dwelling (b)(10). Kirkwood does not publish a separate ADU registration form in the code; compliance is verified through the standard occupancy permit process administered by the Director of Public Services, and a lot found renting out both units to non-owners without the required residency would be treated as a Code violation rather than a licensing infraction.