Tinley Park, IL Building Safety: Fire Sprinkler Requirements (2026)

17 of the Fire Prevention Code lays out separate triggers for a mandatory sprinkler system. The first catches larger or taller commercial-type buildings: any structure with a gross area over 7,500 square feet, or one that exceeds two stories or 27 feet in height, must be sprinklered if it is used for assembly, educational, industrial, institutional, mercantile, storage, or the sale of combustible goods. The second trigger is size alone: any building, regardless of construction type, use or occupancy, that exceeds four stories or 55 feet in height needs a complete sprinkler system.

A third provision, layered elsewhere in the same section, extends a combined sprinkler-and-standpipe requirement to hospitals, nursing homes, day care centers, orphanages, sheltered care homes, retirement complexes and multi-family buildings with more than four units that rent primarily to elderly residents, regardless of how the building is constructed. Gross floor area is defined precisely for these purposes as the ground area within a building's surrounding exterior walls, including roof overhangs and enclosed extensions, with interior fire walls not counted as dividing one structure into separate buildings.

Installation plans must first be approved by an insurance-rating organization such as ISO Commercial Risk Services, then submitted to the Fire Prevention Officer of the Bureau of Fire Prevention for final approval before installation begins; that officer approves plans but does not have authority to decide which buildings must be sprinklered in the first place.