Tinley Park, IL Accessory Structures: Garage Conversions (2026)

Tinley Park requires a building permit for garage conversion projects. The converted space must meet residential building code standards including insulation, egress windows from sleeping areas, smoke and carbon monoxide detectors, heating capacity, and minimum ceiling heights. Foundation and slab conditions must be verified to support habitable use. The zoning ordinance requires each single-family dwelling to maintain a minimum number of off-street parking spaces (typically 2 spaces). Converting an attached garage to living space eliminates those covered parking spaces, and the replacement parking must be provided on-site in a driveway or new garage. Because many Tinley Park lots have minimum driveway widths, replacement parking often is not feasible without creating non-conforming conditions. The conversion may not create a separate dwelling unit (no second kitchen, no separate entrance serving only the converted area, no separate utilities). Exterior appearance should be consistent with the dwelling; large areas of inappropriate siding or remaining garage doors converted to windows without proper framing are common compliance issues.