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

A garage conversion in Orland Park must address two major issues. First, zoning requires each single-family residence to provide a minimum number of off-street parking spaces, typically two spaces, of which at least one must be enclosed. Converting the garage to living space eliminates enclosed parking and may drop the property below the zoning minimum, requiring a replacement garage or a zoning variance. Second, the converted space must meet building code requirements for habitable space: minimum ceiling height (typically 7 feet), insulation (Illinois Energy Conservation Code), egress windows in sleeping rooms, smoke and CO detectors, proper heating capable of maintaining 68 degrees, and permanent electrical and HVAC. Converting a garage into a separate rental dwelling (ADU) is generally not permitted in single-family zones as discussed under ADU rules. A converted garage expanding the existing household's living area (not creating a separate unit) may be permitted with a building permit if parking and habitability requirements are met. Foundation, floor, and moisture management must be appropriate for converted slab-on-grade construction. Illinois Plumbing Code governs any added plumbing fixtures. HOA covenants in Orland Park subdivisions typically prohibit garage conversions outright.