DuPage County, IL Building Safety: Carbon Monoxide Detectors (2026)
Key Facts
- Governing section
- Sec. 8-211(B), (C)
- CO detector placement
- Within 15 feet of every sleeping room
- Power source
- 110-volt wired with battery back-up
- Fire-district letter
- Required before new home/addition permit, Sec. 8-211(D)
- Enforced by
- Building Official, permit review and final inspection
- Violation fine
- $100-$1,000 per day, Sec. 8-117.4
Summary
DuPage County's Building Code requires a carbon monoxide detector within fifteen feet of every room used for sleeping, wired to a 110-volt power source with battery back-up, under Sec. 8-211(B) and (C). It sits in the same section as the county's smoke-detector mandate and residential fire-sprinkler compliance letter requirement.
8-211: - AUTOMATIC FIRE AND CARBON MONOXIDE DETECTION. A.Smoke Detectors Required: Smoke detectors shall be installed in each bedroom, outside of each separate sleeping area in the immediate vicinity of the bedrooms, in all furnace rooms and on each additional story of the dwelling, including basements and cellars but not including crawl spaces and uninhabitable attics.B.Carbon Monoxide Detectors Required: A carbon monoxide detector shall be installed within fifteen feet (15') of every room used for sleeping purposes.C.Power Source: Power source for required detectors to be 110 volt with battery back-up.D.Residential Fire Sprinkler Systems: Applicant must supply a letter from the local fire department/fire district, prior to the issuance of any new residential home or addition permit, indicating compliance with their fire codes or ordinances.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 14 Update 1).
Full Breakdown
Sec. ' Subsection C sets the power standard shared with the section's smoke-detector mandate: the 'power source for required detectors' must be '110 volt with battery back-up,' so a CO alarm cannot rely on batteries alone in new or renovated construction covered by the code. Subsection A, which governs smoke detectors in the same section, separately requires that when additions, repairs or substantial alterations requiring a permit occur, or when a sleeping room is added, 'the entire building shall be provided with smoke detectors located as required for new dwellings,' showing the county treats detector retrofits as triggered by permitted work rather than left voluntary.
Subsection D adds that an applicant must supply a letter from the local fire department or fire district, before the county issues a new residential home or addition permit, confirming compliance with that district's fire codes, a step that in practice lets the local fire authority flag missing detection equipment before a permit is even issued. The requirement is administered by the Building Official as part of permit review and final inspection under Sec. 8-115, so a CO detector's placement and wiring are checked before a certificate of occupancy issues.
Violations & Fines
A missing or noncompliant carbon monoxide detector is a Building Code violation subject to Sec. 8-117.4, the chapter's general penalty: a fine of 'not less than one hundred dollars ($100.00) nor more than one thousand dollars ($1,000.00),' with each day of noncompliance a separate offense. The Building Official first issues a notice of violation under Sec. 8-117.2, giving the owner fourteen days to install the required detector or file an administrative appeal before the county's legal counsel can pursue prosecution.
Frequently Asked Questions
How close does a CO detector have to be to a bedroom?
Can I use a battery-only CO detector?
Does remodeling my house trigger new detector requirements?
What happens if an inspector finds no CO detector?
Sources & Official References
Other rules in DuPage County
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