Joliet, IL Building Safety: Fire Sprinkler Requirements (2026)

Sec. 8-175 adopts the 2015 editions of the International Building Code and International Residential Code by reference, subject to a list of local amendments. " Section R313 of the model IRC is the provision that otherwise mandates automatic fire sprinkler systems in new one- and two-family dwellings and townhouses; Joliet's amendment deletes it outright rather than modifying it, so no citywide sprinkler mandate applies to that class of new residential construction. The same subsection carries other local IRC amendments worth knowing alongside it: Sec. 8-175(b)(2) requires a 10-inch by 20-inch footing for all single-family residential construction, matching the parallel building-code footing amendment in subsection (a)(3), and Sec.

8-175(b)(4) limits the required deck lateral load connection to decks that exceed 30 inches in height. This is a removal, not a substitute standard: Joliet does not impose a smaller residential sprinkler requirement in R313's place, it simply does not require one for townhomes and one- and two-family dwellings. Multifamily and commercial construction remain subject to whatever fire-suppression requirements the adopted International Building Code and International Fire Code otherwise carry, since the R313 removal is confined to the residential code amendment in subsection (b).