Kendall County, IL Building Safety: Fire Sprinkler Requirements (2026)

The 2024 International Residential Code that some jurisdictions adopt includes Section R309, which would require automatic fire sprinkler systems in new one- and two-family dwellings and townhouses. Kendall County adopted the 2024 IRC as its residential building code (Kendall County Code § 8-19) but immediately amended it: item (8) of Section 8-25 instructs that 'Sec. R309 "Automatic Fire Sprinkler Systems" delete in its entirety,' so the sprinkler requirement never took local effect. That leaves fire protection in new houses governed by the Code's other life-safety provisions, smoke-alarm rules carried elsewhere in the adopted IRC, and whatever the local fire protection district requires for water supply and access.

The County Board took the same amend-and-delete approach with several other IRC and IBC default provisions in Sections 8-24 and 8-25, including striking the model exemptions from permitting (Section 8-25(2)) and substituting Illinois-specific codes for plumbing, electrical, private sewage and energy conservation (general amendments at Sections 8-24(10) and 8-25(9)). Because the sprinkler deletion is a straight repeal rather than a substituted standard, no numeric coverage area, water-flow, or design requirement applies to a new single-family or duplex home built in unincorporated Kendall County. Builders and buyers should still confirm requirements with their local fire protection district, since well and hydrant water-supply questions remain subject to Code Official and Health Department review, separate from the deleted Section R309 sprinkler mandate itself.