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

Orland Park's zoning code restricts single-family residential districts (R-1, R-2, R-3 single-family) to one dwelling unit per lot. Accessory structures may not contain a second dwelling unit with independent cooking, sleeping, and sanitation facilities. Multi-family (R-4 and higher) districts permit multiple dwellings as the principal use. Creating a second dwelling unit within or behind a single-family home without a zoning change or variance is generally prohibited. Unlike the City of Chicago, which adopted an ADU pilot ordinance in 2021, Orland Park has not formally authorized residential ADUs Village-wide. Legacy second units that predate zoning may continue as legal nonconforming uses if documented. Homeowners interested in creating a legal ADU typically need to apply for a zoning variance or special use permit through the Plan Commission and Village Board, which is a discretionary process. Cook County property tax assessments may also be affected by adding a second dwelling unit. HOA subdivisions almost universally prohibit ADUs through private covenants regardless of zoning.