Wisconsin Carbon Monoxide Detector Requirements for Hotels and Short-Term Rentals

A missing carbon monoxide alarm can close a Wisconsin lodging facility. ATCP 72, overhauled in full with effect from 25 January 2026, designates it a Priority violation, which is the category capable of triggering immediate closure rather than a correction notice and a return visit. Wisconsin hotel carbon monoxide detector duties start above that in Wis. Stat. 101.149, whose definition of a residential building takes in any public building used for sleeping or lodging, tourist rooming houses and bed and breakfasts. The building-code layer beside them changed in 2025: chapter SPS 362 moved to the 2021 International Building Code and SPS 362.0915, Wisconsin's own substitute for the model Section 915, did not come across.

Last verified: August 24, 2026

Key Takeaways

The trigger is a fuel-burning appliance or an attached garage, and no size threshold sits in front of it, so a two-hundred-room hotel and a one-unit cabin answer the same rule.
Kenosha cuts the repair clock from five days to one. Wisconsin gives an owner five days to restore a detector to working order after written notice from an occupant, and Section 16.25(B)(2) gives the Responsible Person twenty-four hours from receipt of that notice where a detector is not functional or has been removed by somebody other than the occupant. Over a weekend that is a device replaced on Saturday rather than the following Thursday.
Kenosha balances the hard deadline with a shield. Paragraph 3 protects the Responsible Person from damages for a false alarm from a reasonably maintained detector, and for a failure caused by another person tampering with, removing or destroying the device, or by a faulty detector that was reasonably maintained. Paragraph 4 bars anyone from tampering with, removing, destroying, disconnecting or taking the batteries from an installed detector except during inspection, maintenance or replacement, and paragraph 5 keeps the state exemption where a building has no attached garage and no fuel-burning appliances.
Madison publishes what a missing detector is worth in money. Section 32.04 item 41 is a rent abatement schedule priced by position: 5 to 10 percent of rent per affected area for a detector missing in the basement, 10 to 25 percent for one missing on a floor level other than an attic, garage or storage area, 10 to 25 percent for one missing outside a separate sleeping area in the immediate vicinity of the sleeping units, and a further band where a fuel-burning appliance sits inside a sleeping room.
Madison also reaches a housing type the state rules do not name. Section 28.151(b) requires every tiny house to carry a smoke detector, a carbon monoxide detector and a fire extinguisher, and paragraph (c) restricts heating to listed vented gas appliances, liquid propane or natural, or to electric heat.
Five local provisions read like rules and are not. Madison Sections 29.22 and 34.01 and Sturgeon Bay Section 6.17 adopt SPS 328 by reference alongside the rest of the state code family, which is adoption rather than divergence. Madison Section 30.20 and La Crosse Section 103-200 both cap the products of combustion from a gas burner at 0.04 percent carbon monoxide, which regulates the gas rather than the alarm and asks for no detector.

Legal Summary

Wisconsin requires carbon monoxide detectors in all hotels, motels, tourist rooming houses, bed and breakfasts, and short-term rentals, including Airbnb and VRBO listings, when the property contains a fuel-burning appliance or has an attached garage. The foundational law is Wisconsin Statute § 101.149, which defines a "residential building" broadly to include any public building used for sleeping or lodging, tourist rooming houses, and B&Bs. Administrative Code Chapter ATCP 72, entirely overhauled effective January 25, 2026, governs day-to-day operational requirements for licensed lodging facilities and designates a missing CO alarm as a Priority violation capable of triggering immediate facility closure. The building-code layer used to be SPS 362.0915, which substituted Wisconsin's own technical standard for the model code's Section 915. It is gone. The Legislature's current chapter SPS 362 runs SPS 362.0901 through .0913 with no .0915, removed by Register August 2025 No. 836 when the chapter moved to the 2021 International Building Code with effect from 1 September 2025. A lodging building permitted since that date answers the model Section 915 unamended; one permitted earlier was built to the repealed section. Wisconsin's 2026 regulatory update introduced updated placement distances and new enforcement tools that every lodging operator, from a 200-room hotel to a one-unit Airbnb cabin, must understand.

Who Is Covered

Every type of Wisconsin lodging facility is covered. Under Wis. Stat. § 101.149(1)(b), a "residential building" subject to the CO detector mandate includes hotels, motels, tourist rooming houses, and bed and breakfast establishments. Wisconsin classifies any short-term rental offered for pay to transients, whether listed on Airbnb, VRBO, or any other platform, as a tourist rooming house under ATCP 72.03(95), and such properties must be licensed by DATCP when rented more than 10 nights per year. Dormitories and other buildings used for sleeping are also covered as "public buildings used for sleeping or lodging purposes." Hospitals and nursing homes are explicitly excluded from § 101.149. No size threshold or building-age threshold eliminates the requirement once a trigger condition (fuel-burning appliance or attached garage) is present.

Hotels already standing: covered too. The Wisconsin requirement reaches an existing hotel and not only one being built.

Operator Responsibilities

The property owner, or, for licensed lodging facilities, the license holder, is solely responsible for installation, maintenance, and timely repair of CO detectors. Responsibility does not transfer to guests or tenants.

Installation. Detectors must be installed at all locations required by § 101.149(2) before the property is occupied, following manufacturer directions and specifications per § 101.149(2)(e).

Maintenance. Under § 101.149(3)(a), owners must "reasonably maintain every carbon monoxide detector in the residential building in the manner specified in the instructions." Detectors must be replaced by their manufacturer-specified expiration date.

Response to notice. If an occupant provides written notice that a detector is missing or non-functional, the owner must repair or replace it within 5 days per § 101.149(3)(b). Under ATCP 72.18(12)(h), when DATCP or its agent notifies an operator of a non-functional or expired alarm, the operator must confirm repair or replacement to DATCP within 5 calendar days.

Tampering prohibition. Wisconsin Statute § 101.149(4) prohibits any person, including guests and staff, from tampering with, removing, disconnecting, or removing batteries from an installed CO detector except during inspection, maintenance, or replacement. Operators should post clear guest notices about this prohibition.

Liability protection. Owners are protected from liability for false alarms when the detector was reasonably maintained, and from liability for detector failure caused by tampering by someone other than the owner, per § 101.149(3)(c).

Installation and Technical Requirements

CO detectors are triggered by the presence of a fuel-burning appliance (furnace, boiler, water heater, fireplace, stove, or gas dryer) or an attached garage. When triggered, placement must comply with both § 101.149(2) and ATCP 72.18(12).

Under ATCP 72.18(12)(e), effective January 25, 2026, detectors in individually keyed units must be installed outside each separate sleeping area within 21 feet of any door to a sleeping room, measured along a path of travel, and inside a sleeping room where a fuel-burning appliance sits in that room or its attached bathroom. Wisconsin wrote this itself and it is not the model code's rule, so the sleeping-unit-versus-corridor question that governs most states does not arise here; what governs is a measured distance along the route a guest would walk.

Ceiling mounting is an option in one place rather than a requirement anywhere. Under 72.18(12)(c)2, where the fuel-burning appliance is outside the guest unit, an alarm is not required in each unit if one is provided either between the appliance and the unit or on the ceiling of the room containing the appliance. That is a way of covering several units with one device, not a mounting rule for the units themselves.

All standalone CO alarms must meet UL 2034. Detectors connected to a building fire alarm system must meet UL 2075. Combination smoke/CO devices are acceptable. The wiring rule changed with the code, and the older one still describes the building it was applied to. SPS 362.0915(2)(c)-(d) required construction initiated on or after 1 October 2008 to carry hardwired detectors with battery backup, interconnected within each unit, and left battery-operated units acceptable in what was built before that; the section was removed from the code by Register August 2025 No. 836. New work now answers the model Section 915.4.1, which requires an alarm to take primary power from the building wiring where that wiring is served from a commercial source and to fall back to a battery, with permanent wiring and no disconnecting switch beyond overcurrent protection, excepting only a building without commercial power. It sets no construction-date threshold and requires no interconnection, and neither Wis. Stat. 101.149 nor ATCP 72.18(12) adds a wiring duty of its own.

Enforcement

Three agencies share enforcement authority. DATCP and its authorized local agent health departments conduct annual inspections of licensed lodging facilities statewide. Under the 2026 ATCP 72, a missing CO alarm is a Priority (P) violation, indicating immediate risk, and triggers closing criteria under ATCP 72.26(1)(f), empowering DATCP to issue an immediate temporary closure order. DATCP may also summarily suspend or revoke a license without prior notice when violations pose a serious danger to public health under ATCP 72.10. DSPS enforces the commercial building code, chapter SPS 362, which since 1 September 2025 applies the model Section 915 without the substitution SPS 362.0915 used to supply. Local fire departments and marshals enforce fire prevention codes and may inspect for CO compliance under § 101.647(4). Municipalities may authorize local inspectors under city, village, town, or county ordinance.

Penalties

Under § 101.149(8)(a), after an inspection finding a violation the enforcing agency issues a correction order. Failure to correct within the specified time (typically 5 days) results in a $50 per day forfeiture for each day the violation continues. Tampering with an installed CO detector carries a fine of up to $10,000 and/or up to 9 months imprisonment for a first offense under § 101.149(8)(c). A second or subsequent tampering offense is a Class I felony under Wisconsin law. DATCP may additionally suspend or revoke the lodging facility license, which effectively halts operations.

Local Override Warning

Wisconsin municipalities cannot weaken statewide CO detector requirements but may impose additional lodging-specific licensing conditions consistent with state law. Municipal STR programs may require proof of CO detector compliance during permit issuance or local safety inspection steps. A reading of six municipal codes in August 2026 found none aimed specifically at lodging, but two that reach any residential building an operator might own. Kenosha Section 16.25(B)(2) shortens the state's five-day repair window to twenty-four hours after written notice from an occupant. Madison Section 32.04 publishes a rent abatement schedule that prices a missing detector by location, which matters to anyone letting a unit for more than a transient stay. Madison Section 28.151(b) also requires a smoke detector, a carbon monoxide detector and a fire extinguisher in every tiny house and limits heating to listed vented gas or electric. One thing about the state clock is worth knowing before treating either city rule as an addition. Wis. Stat. 101.149(3)(b) gives the owner five days from an occupant's written notice to repair or replace the detector, and 101.149(3)(am) attaches the same five days to written notice from a person certified under 101.12(4) or 101.14(4r), an inspector. Both routes end at five days, so Kenosha's twenty-four hours cuts a deadline the state had already started rather than supplying one it never gave. Madison also regulates the appliance rather than the alarm at Section 30.20, forbidding a gas conversion burner to be left in operation unless it is adjusted so the products of combustion contain no more than 0.04 percent carbon monoxide, sampled from the breeching as near the furnace as possible, with La Crosse Section 103-200 setting the same ceiling for gas burner installations of 400,000 BTU and smaller. Operators should verify all city and county permit requirements before operating a licensed lodging facility.

Frequently Asked Questions

Are carbon monoxide detectors legally required in Wisconsin hotels?

Yes. Wisconsin Statute § 101.149 requires CO detectors in all hotels, motels, and other buildings used for sleeping or lodging when a fuel-burning appliance is present or an attached garage exists. The requirement applies regardless of hotel size or building age. Administrative Code ATCP 72, overhauled effective January 25, 2026, further designates a missing CO alarm as a Priority violation, the highest severity level, which can trigger an immediate facility closure order issued by DATCP or its authorized local agent.

Are Airbnb and VRBO hosts in Wisconsin covered by the same CO detector requirements?

Yes. Wisconsin classifies any short-term rental rented to the public, including Airbnb and VRBO listings, as a tourist rooming house under ATCP 72.03(95). Properties rented more than 10 nights per year must obtain a DATCP tourist rooming house license under Wis. Stat. § 66.1014(2)(d)(2), which subjects them to the full ATCP 72 framework, including CO alarm requirements under ATCP 72.18(12). The CO detector obligation under Wis. Stat. § 101.149 applies independently of licensure status whenever the fuel-burning-appliance trigger condition is met.

Who is responsible for installing and maintaining CO detectors in Wisconsin lodging?

The property owner, or license holder for licensed lodging facilities, bears sole responsibility for installation, maintenance, and timely repair under Wis. Stat. § 101.149(3)(a). Responsibility does not transfer to guests. If an occupant provides written notice of a missing or non-functional detector, the owner must repair or replace it within 5 days per § 101.149(3)(b). Under ATCP 72.18(12)(h), when notified by DATCP of a non-functional alarm, the operator must confirm repair to DATCP within 5 calendar days. Tampering with an installed detector is prohibited for all persons, including guests.

Where exactly do CO detectors need to be placed in Wisconsin hotel or STR rooms?

Under ATCP 72.18(12)(e), effective January 25, 2026, CO alarms in individually keyed units go outside each separate sleeping area within 21 feet of any door to a sleeping room, measured along a path of travel, and inside a sleeping room where a fuel-burning appliance sits in that room or its attached bathroom. Ceiling mounting is not a requirement for guest rooms: under 72.18(12)(c)2 it is one of two alternatives, alongside a device between the appliance and the unit, that lets an operator cover units served by an appliance located outside them. ATCP 72.18(12)(f) requires conformity to UL 2034 with the listing mark, and installation follows the manufacturer's directions under (12)(g).

What penalties apply for missing CO detectors in a Wisconsin hotel or short-term rental?

Under Wis. Stat. § 101.149(8)(a), after a violation is found during inspection, the enforcing agency issues a correction order. If not corrected within the specified time, typically 5 days, a $50 per day forfeiture applies for each day the violation continues. DATCP may also suspend or revoke a lodging license under ATCP 72.10, effectively halting operations. Tampering with an installed CO detector carries a fine of up to $10,000 and/or up to 9 months imprisonment for a first offense; a second offense is a Class I felony under § 101.149(8)(c).

Can local Wisconsin cities or counties require stricter CO detector rules than state law?

Wisconsin municipalities cannot enact building code standards that conflict with state commercial building rules, but they can impose CO detector compliance as a condition of local lodging licenses. Municipal STR programs may require proof of a valid DATCP tourist rooming house license and may include local inspection steps tied to CO detector compliance. County-level permit layers may also apply in some jurisdictions. Always verify applicable municipal and county requirements directly, local rules may impose additional safety inspection steps beyond the statewide ATCP 72 baseline.

Disclaimer: This page explains the law as it stood on August 24, 2026. It is general information, not legal advice, and reading it creates no attorney-client relationship. Requirements vary by city, county and building type, and statutes and codes are amended: confirm the current text with the issuing authority before acting on it. Each requirement here cites the instrument it comes from, so you can check it at source.

Sources and References

Wisconsin Statute § 101.149, Carbon monoxide detectors , § 101.149(1)(b), (2), (3), (4), (8)
Wisconsin Administrative Code ATCP 72, Hotels, Motels, and Tourist Rooming Houses (eff. January 25, 2026) , ATCP 72.03(95), 72.18(11) smoke alarms, 72.18(12)(a) to (i) carbon monoxide alarms, 72.26(1)(f), 72.10
Wisconsin Administrative Code SPS 362.0915, Carbon monoxide detection in commercial buildings , SPS 362.0915(1)-(3), under the 2015 International Building Code
DATCP, Tourist Rooming Houses program page , Licensing requirements, ATCP 72 applicability
Wisconsin Statute § 66.1014, Regulation of short-term rentals , § 66.1014(2)(d)(2)