Chelan County, WA Accessory Structures: ADU Owner Occupancy (2026)

200, accessory dwelling units in the unincorporated county are capped at one ADU per lot alongside a single-family home or duplex, limited to 1,200 square feet of floor area (excluding garages, storage, stairwells, decks and patios), and require one dedicated parking space beyond what the primary residence needs. 290. An ADU that is never rented short-term carries no owner-occupancy mandate under this subsection. Recreational vehicles can never qualify as an ADU under subsection (6), and a common driveway must serve both units where feasible under subsection (7).

ADUs do not count toward density calculations in any zone under subsection (8). Community Development's planning and code enforcement staff review ADU permits against these standards, and enforcement of the occupancy tie-in runs through the short-term rental permitting and Title 16 enforcement process once a rental use is proposed. Owners who apply for a short-term rental land use permit on a property with an ADU must demonstrate, through proof such as government identification, voter registration, or utility bills, that they occupy one of the two units. Losing that occupancy after obtaining an STR permit exposes the property to permit revocation under the short-term rental provisions.