Tinley Park, IL Accessory Structures: ADU Rules (2026)

Tinley Park's zoning ordinance establishes single-family (R-1, R-2, R-3) and multi-family (R-4, R-5) residential districts. Single-family districts permit only one dwelling unit per lot. The Village does not have a specific ADU or accessory dwelling ordinance. Finished basements, garage conversions, and second-floor additions are permitted only as part of the single-family dwelling and may not function as separate living units with their own kitchens, separate entrances, and separate utility connections. Installing a second kitchen (defined by the presence of a stove or other permanent cooking appliance) in a single-family home typically requires a statement that it will not be used for a separate dwelling unit and often prompts additional zoning review. 'In-law arrangements' where family members share the home without creating a separate unit are generally acceptable. Creating a legal ADU on a single-family lot would require a zoning text amendment or a use variance approved by the Zoning Board of Appeals and Village Board, which is uncommon. Properties legally established as two-family dwellings prior to zoning changes may retain non-conforming status.