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

The 2021 International Residential Code, in its unamended form, requires an automatic fire sprinkler system in new townhouses (Section R313.1) and in new one- and two-family dwellings (Section R313.2). Kane County Code section 6-4, Amendments To Residential Code, specifically overrides both provisions: 'R313.1 Townhouse automatic fire sprinkler systems. Change "shall" to "may".' and 'R313.2 One- and Two-family dwellings automatic fire systems. Change "shall" to "may".' That single word change converts a mandatory installation requirement into a discretionary one, meaning a builder in unincorporated Kane County can choose to install residential fire sprinklers but is not required to under the county's building code.

This amendment applies only within the unincorporated area; a municipality such as Aurora, Elgin, Geneva, St. Charles, Batavia, Carpentersville, or South Elgin could adopt its own, stricter sprinkler requirement inside city limits, so the county's optional standard does not carry over once a parcel is annexed. The amendment sits alongside other Chapter 3 amendments in the same 2021 code cycle, including a rewritten emergency escape and rescue opening requirement (Section R310.1) and townhouse fire-separation wall standard (Section R302.2), both adopted or last amended by Ordinance 21-475 on November 9, 2021.

Because sprinklers remain optional rather than banned, a homeowner who wants one may still install it as part of a permitted building project, subject to the same permit and inspection process as any other residential construction under Section 105 and Section 110.