Chicago, IL Building Safety: Carbon Monoxide Detectors (2026)

Under Chicago Building Code § 14X-5-504.9, carbon monoxide alarms must be installed in existing structures per Section 915.4 of the Chicago Building Code. Section 14X-5-504.9.1 requires alarms in dwelling and sleeping units that contain a fuel-burning appliance or fireplace, are served by a fuel-burning forced-air heating or cooling system, share ductwork or openings with a space containing a fuel-burning device, have a door leading directly to a private garage, or sit immediately above a private garage. Section 14X-5-504.9.3 separately requires an alarm in any room, regardless of occupancy, that contains a fuel-burning heating unit or water heater. Battery-operated alarms are allowed only where the code in effect at installation did not require hard-wired units; an approved carbon monoxide detection system under Section 915.5 is an acceptable alternative.