Tippecanoe County, IN Accessory Structures: ADU Rental Restrictions (2026)

Section 4-12 of the county's Unified Zoning Ordinance (Third Edition, Amendments 115 & 124) permits one accessory dwelling unit (ADU) per lot or parcel in unincorporated Tippecanoe County, but only in rural zones and only when the section's qualifications are met. Subsection (f) restricts ADU occupancy to one family, exclusive of the occupants of the primary dwelling unit, meaning the principal house can be occupied by a separate family at the same time as the ADU. Subsection (k) goes further on short-term and rental use: transient guest houses are not permitted in ADUs at all, and if the property owner lives in the ADU as a primary residence, the principal dwelling unit likewise cannot be run as a transient guest house.

Home occupations and rural home occupations are allowed inside an ADU only if they remain accessory to the ADU's residential use, so a converted ADU cannot be operated as a standalone business or lodging unit. Illegal ADUs that existed before the amendment can be brought into legal conformance through a permit under subsection (l), and the ordinance separately flags that properties in West Lafayette may also face that city's own rental inspection requirements, a reminder that the county's rural-zone ADU rule does not extend into incorporated municipalities. The Area Plan Commission, which administers the UZO for the county and its member jurisdictions, reviews ADU permit applications through the Administrative Officer.