What Kentucky Requires for CO Detectors in New Construction

Last verified: August 24, 2026

Kentucky carbon monoxide detector laws in statewide code practice are tied to the Kentucky Residential Code and its adoption language in 815 KAR 7:125. Two numbers matter and it is worth getting them the right way round, because guidance published elsewhere often does not. The permit trigger is Section R315.2.2, headed Alterations, Repairs and Additions, which is the provision that catches work on an existing house. Section R315.3 is headed Location and says where the alarm goes, not when one is required. The current instrument is the 2018 Kentucky Residential Code, Third Edition, effective 1 August 2024, built on the 2018 International Residential Code, and the numbering above is read from that code. The clearest statewide trigger appears when permit-required work affects existing dwellings with fuel-fired appliances or attached-garage conditions, which brings CO alarm obligations into active inspection workflow. Homes and many rental contexts can be affected through this code path, so owners and managers should treat detector compliance as part of standard project closeout and occupancy readiness.

Kentucky's legal structure is code-centric rather than one standalone penalty statute, making documentation of trigger conditions, installation status, and correction activity especially important. Where URLTA duties apply, landlords and tenants should align lease operations with applicable health-and-safety code obligations.

Kentucky operators should preserve inspection correspondence and code citations in every turnover file.

Key Takeaways

CO detector requirements for Kentucky
Applies to homes?	Yes
Applies to rentals?	Yes
Applies to hotels/STRs?	Yes
Applies to schools?	Yes, under a condition
Applies to workplaces?	No

Schools and workplaces

Schools: it depends, and the test is one you can apply to the building itself. Read Kentucky's own rendering rather than the model text, because the two differ and the difference is the answer. 815 KAR 7:120 Section 2 makes the 2015 International Building Code the mandatory state building code for all buildings constructed in Kentucky, and Section 915.1.1 as Kentucky renders it requires carbon monoxide detection in "Group I-1, I-2, and R occupancies and in classrooms in Group E occupancies" in the Section 915.2 locations where any of the conditions in Sections 915.1.2 through 915.1.6 exist. So a Kentucky classroom is covered where it holds a fuel-burning appliance or fireplace, is served by a fuel-burning forced-air furnace, sits in a building holding such equipment with an opening that communicates, or adjoins an attached private garage. An all-electric school with no attached garage meets none of them. In the 2015 edition Kentucky adopts, the classroom's duty does not stop at the detector. Section 915.2.3 requires detectors in classrooms in Group E occupancies and requires their alarm signals to be "automatically transmitted to an on-site location that is staffed by school personnel", excepting a Group E occupancy with an occupant load of 30 or less. State that as the base rather than as Kentucky's own text, because Kentucky's rendering of Section 915 could not be read to 915.2.3 on 2026-08-24: the Department of Housing, Buildings and Construction's own PDF of the 2018 Kentucky Building Code Fourth Edition lists Section 915 in its contents and the text was beyond the reach of every extraction route tried, and the code-catalogue view of Kentucky's chapter 9 stops at Section 914. Kentucky does amend 915.1.1, as the next paragraph shows, so a reader relying on the transmission duty for a Kentucky school should confirm 915.2.3 against the Fourth Edition itself. One group is missing from that list and it is not Group E. The 2015 model text reads "Group I-1, I-2, I-4 and R", and Kentucky's rendering has no I-4. Group I-4 is day care, so a Kentucky day care centre is outside Section 915.1.1 while the classroom down the road is inside it. Two other jurisdictions' 2015 views were read as a control and both carry I-4, so the omission is Kentucky's rather than the edition's, and the instrument it comes from is named in the adopting rule: 815 KAR 7:120 makes the 2015 International Building Code mandatory statewide "with the exception that Kentucky amendments in the 2018 Kentucky Building Code shall supersede any conflicting provision". The amendment document is the 2018 Kentucky Building Code, Fourth Edition, February 2024, and the regulation carrying it took effect on 3 December 2024. So the base edition is 2015 and has not moved, and what differs from the model is Kentucky's own amendment rather than a later cycle.

Workplaces: Kentucky places no carbon monoxide detection duty on an office, shop or other workplace. Federal and state occupational rules set an exposure limit for carbon monoxide in air; they do not require a detector to be installed, and this row is about installation. Section 915.1.1 of the 2015 International Building Code, which 815 KAR 7:120 Section 2 makes mandatory statewide, reaches Group I-1, I-2 and R occupancies and classrooms in Group E occupancies, and names no Group B, F, M or S. Kentucky writes no carbon monoxide statute of its own, and because the building code is mandatory and uniform under KRS 198B.040(7) and 198B.050 a locality cannot write a construction rule to add one. The local carbon monoxide rules found in Kentucky sit in rental licensing chapters, at Covington Section 110.31(B)(1)(a) and Louisville Section 115.520, and both reach dwellings rather than workplaces.

When Are CO Alarms Required?

Buildings with fuel-burning appliances
Buildings with attached garages
When building permits are required
Existing dwellings with permit-required work are addressed by Section R315.2.2, Alterations, Repairs and Additions, which is the trigger provision rather than R315.3.

Where to Install CO Alarms

Carbon monoxide alarms must be provided in accordance with Section R315.1 when the Section R315.2.2 permit conditions are met, and sited as Section R315.3 directs.

For detailed placement guidance beyond legal requirements, see where to place carbon monoxide detectors.

Device Requirements

Device listing, power, and technical details follow the adopted R315 code pathway in Kentucky Residential Code materials.

Landlord and Tenant Responsibilities

Landlord: In URLTA jurisdictions, landlords must comply with applicable building and housing codes affecting health and safety; outside URLTA areas, allocation is more lease-driven. Which jurisdictions those are is not answerable from a statute, because KRS 383.500 leaves adoption to local ordinance and no statutory list exists or could. Compiled from secondary sources and consistent across several of them: four counties, Jefferson, Fayette, Oldham and Pulaski, and fifteen cities, Barbourville, Bellevue, Bromley, Covington, Dayton, Florence, Georgetown, Ludlow, Melbourne, Newport, Shelbyville, Silver Grove, Southgate, Taylor Mill and Woodlawn. Treat it as a starting point and confirm with the city or county. Two have since been read at source: Fayette adopted by Ordinance No. 98-84, and Pulaski by an ordinance of its Fiscal Court taking KRS 383.505 through 383.705 in its entirety and without amendment, both readings in 1993. Provision: Section 915.1 and 915.1.1.

Tenant: In URLTA jurisdictions, tenants have general duties to maintain safe premises and report issues; CO-specific operation should be documented in lease policies. Provision: Section 915.1 and 915.1.1.

Cited Kentucky sources emphasize code-triggered obligations and do not provide one universal statewide landlord-tenant CO matrix.
The landlord-tenant layer is local and the building-code layer is not, which is the split that decides most Kentucky questions. KRS 383.500 lets a city, county or urban-county government adopt the Uniform Residential Landlord and Tenant Act at KRS 383.505 to 383.705, whole rather than in pieces, so nineteen jurisdictions have it and the rest do not. The Kentucky Residential Code is mandatory and uniform statewide either way, so the permit trigger reaches a rental in Paducah exactly as it reaches one in Louisville. What changes across the line is who owes what to whom afterwards, not whether an alarm is required.

Full Kentucky landlord and tenant carbon monoxide duties, with citations

Enforcement

Enforced by: Local permitting and inspection authorities, applying the mandatory uniform code the Department of Housing, Buildings and Construction promulgates under KRS 198B.040(7) and 198B.050. Which half of it applies follows the building: 815 KAR 7:125 governs one- and two-family dwellings and townhouses, and 815 KAR 7:120 governs everything else, lodging included. On a property already standing the fire official matters more than the building department, because Kentucky's structure creates no routine building-code inspection of a building in use.

Enforcement typically occurs:

During permit review and inspections when the Section R315.2.2 trigger conditions are met.
During correction and reinspection workflow after identified deficiencies.

What a Tenant Can Do in Kentucky

Read this before the table:This row is not the law of Kentucky. KRS 383.500 authorises a city, county or urban-county government to adopt the Uniform Residential Landlord and Tenant Act as set out in KRS 383.505 to 383.705, and a jurisdiction that adopts takes it whole rather than in pieces. Because adoption happens by local ordinance, no statutory list of adopters exists or could exist. Kentucky is the only state in the fifty-one where the set of places its landlord-tenant act governs cannot be read off the statute at all. Tennessee also runs a partial act, but 66-28-102 names its counties by a population test, so a Tennessee reader can at least look the answer up. The list compiled from secondary sources, consistent across several of them, is four counties, Jefferson, Fayette, Oldham and Pulaski, and fifteen cities: Barbourville, Bellevue, Bromley, Covington, Dayton, Florence, Georgetown, Ludlow, Melbourne, Newport, Shelbyville, Silver Grove, Southgate, Taylor Mill and Woodlawn, many of them clustered in Kenton and Campbell counties. That list is secondary and should be treated as a starting point: the authoritative check is whether the reader's own city or county passed the ordinance. Outside the adopting jurisdictions none of the five values below applies, and the lease and common law govern instead. The sections here were read from the act as published by the Lexington-Fayette Urban County Human Rights Commission, which is the text as adopted in one of those jurisdictions.

The jurisdictions on that compiled list, 19 of them:

Jefferson County
Fayette County
Oldham County
Pulaski County
Barbourville
Bellevue
Bromley
Covington
Dayton
Florence
Georgetown
Ludlow
Melbourne
Newport
Shelbyville
Silver Grove
Southgate
Taylor Mill
Woodlawn

If your city or county is not on that list, check whether it passed the ordinance before relying on any row below.

When a carbon monoxide alarm stops working in a rented home in Kentucky, these are the five routes a tenant can take and where each one comes from.

"Via general law" means the Kentucky carbon monoxide statute itself is silent and the remedy comes from the state's landlord-tenant law instead. The remedy is available even though the alarm rule does not contain it.

Tenant remedies for a defective carbon monoxide alarm in Kentucky, with the citation or the body of law searched for each.
Rent withholding	Via general lawKRS 383.645. A counterclaim, with an ending most states do not offer. In an action for possession for nonpayment, or for rent while the tenant is in possession, the tenant may counterclaim for any amount recoverable, and the court may order rent paid into court and work out what each side owes. If no rent remains due after that accounting, judgment is entered for the tenant in the possession action itself rather than leaving the tenancy in doubt. The risk sits on the other side of the same section: a counterclaim without merit and not raised in good faith exposes the tenant to the landlord's attorney's fees.
Repair and deduct	Via general lawKRS 383.635. Among the narrowest deductions in the fifty-one on both money and mental state, alongside Vermont and Delaware. The cap is the greater of $100 or one-half of the monthly rent, below Arizona and Missouri at $300 and far below Hawaii at $1,000. And willfulness is required twice over: the landlord must willfully and materially fail to comply, and must then willfully fail to comply within fourteen days of the tenant's written notice. The tenant must also submit an itemized statement for work actually done and paid for in full before deducting. A tenant who takes the essential-services route at 383.640 instead gives up this section for that breach.
Right to end the lease	Via general lawKRS 383.625(1). One notice carries two dates: the landlord has fourteen days to remedy, and the agreement terminates on a date the tenant names not less than thirty days after receipt. A landlord who adequately remedies before that date stops the termination. A substantially similar breach recurring within six months drops the requirement to at least fourteen days' notice, and a tenant cannot terminate for a condition caused by the tenant, the tenant's family or someone there with their consent.
Notice the tenant must give	Via general lawKRS 383.625(1). No waiting period before serving, but the notice has to specify the acts and omissions constituting the breach and name the termination date. Kentucky then needs a second and different notice for the deduction route under 383.635, which is a notice of the tenant's intention to correct the condition at the landlord's expense rather than a notice of breach.
Landlord cure period	Via general law, 14 daysKRS 383.625(1). Fourteen days to remedy, with the tenancy ending no sooner than thirty days after receipt, so the landlord's window and the tenant's exit are different numbers in the same sentence. The same fourteen days runs under 383.635 for the deduction, shortened there to as promptly as conditions require in an emergency, which is the only place Kentucky moves faster for a hazard.

Remedies last checked 2026-08-03. Compare Kentucky with the other states.

What Kentucky Requires in Lodging

The Kentucky carbon monoxide requirement reaches hotels and short-term rentals.

Hotels already standing: it depends, and on a separate test from the one that decides coverage generally. Which fire code edition the local authority enforces decides it, and that is a local question rather than a statewide one. The building code is uniform: 815 KAR 7:120 makes the International Building Code mandatory for all buildings constructed in Kentucky, and its Section 915.1 governs new buildings on its own terms while sending existing buildings to Chapter 11 of the International Fire Code. An edition of that fire code carrying the existing-building carbon monoxide provision brings the whole property into scope; an edition without it leaves the requirement attached to permitted work. Kentucky's structure creates no routine building-code inspection of an operating hotel, so ask the local fire official which edition they enforce.

Operator duty: Kentucky is one of the states where lodging needs no separate rule, because the building code is mandatory and uniform. KRS 198B.040(7) and 198B.050 require the Department of Housing, Buildings and Construction to promulgate a mandatory uniform state building code covering the construction of all buildings in the state, and 815 KAR 7:120 Section 2 carries that out: the 2015 International Building Code "shall be the mandatory state building code for all buildings constructed in Kentucky", with the Kentucky amendments in the 2018 Kentucky Building Code overriding any conflict. Only three things are carved out, and a hotel is none of them: one- and two-family dwellings and townhouses, which go to the residential code at 815 KAR 7:125, and manufactured homes under KRS 227.550 through 227.665. Section 915 of the adopted edition requires carbon monoxide detection in Group I-1, I-2 and R occupancies, and a hotel is Group R-1, wherever a sleeping unit holds a fuel-burning appliance or fireplace, is served by a fuel-burning forced-air furnace, or sits near fuel-burning appliances outside the unit. One boundary is worth knowing before a refit: Section 915.1 governs new buildings itself and sends existing buildings to Chapter 11 of the International Fire Code, so an operator working on an older property should ask the local authority which fire code edition it enforces.

Full Kentucky hotel and short-term rental requirements

Penalties for Non-Compliance

The cited Kentucky sources focus on permit and inspection enforcement rather than a dedicated statewide CO-specific fine schedule.

Additional Notes

Kentucky has no carbon monoxide statute, and the instrument a search reaches first is the residential code, which makes the state look as though it answers only permitted work on houses. Lodging is answered elsewhere and without a trigger. 815 KAR 7:120 Section 2 makes the 2015 International Building Code the mandatory state building code for all buildings constructed in Kentucky and carves out exactly three things, one- and two-family dwellings, townhouses and manufactured homes, so Section 915 reaches a hotel as a Group R-1 occupancy. Read R315.3 for an existing house and 815 KAR 7:120 for everything the residential code does not take.
For URLTA and lease-duty interpretation, local legal counsel review is recommended in mixed-jurisdiction portfolios.
The section numbers on this page are the 2018 numbering and they are correct for Kentucky today, but they are not permanent and the reason is worth knowing before reading any national guidance. Carbon monoxide alarms sit in Section R315 of the International Residential Code through the 2018 and 2021 editions. The 2024 edition reordered Chapter 3, moved the alarms to Section R311, and gave R315 to sleeping lofts. Kentucky's current code is the 2018 Kentucky Residential Code, Third Edition, effective 1 August 2024 and built on the 2018 model edition, so R315 is the right number here and will stay right until the state adopts a 2024-based edition. What changes on that day is not just the number but what the old number points at. A reference to R315 does not stop working when the edition moves, it quietly starts describing sleeping lofts instead, with nothing to warn the reader. Most guidance published anywhere still says R315, so expect to keep meeting it, and check the edition it was written against before relying on it.

Local Rules That Differ From State Law

At least one Kentucky municipality sets CO requirements that go beyond the statewide rule. Where your property sits decides which applies, and the stricter one governs.

Covington

Covington is the only Kentucky city found writing its own placement rule, and it applies to every licensed rental in the city rather than to work under permit. Section 110.31(B)(1)(a) requires every residential rental property dwelling unit in the city to be equipped with at least one approved carbon monoxide alarm in operating condition within 15 feet of every room used for sleeping purposes. There is no fuel-burning trigger in that sentence: the duty attaches to the licence rather than to what the building contains. Subsection (A) defines an approved alarm as one complying with the rules and regulations of the National Fire Protection Association and State Fire Marshal standards and bearing the label of a nationally recognised testing laboratory, and pins NFPA 720 to its 2005 edition "and as modified thereafter". Worth knowing before buying to that number: NFPA withdrew NFPA 720 in August 2018 and folded carbon monoxide alarms into Chapter 29 of NFPA 72, so the ordinance names a standard nobody has maintained for seven years and the phrase "as modified thereafter" points at modifications that stopped. A current listing to UL 2034 with installation to NFPA 72 is what a testing laboratory and an inspector will both recognise. The section sits in Chapter 110, the licence fees and taxes chapter, which is where a uniform-code state leaves room. Section 127.17 then requires the Code Enforcement Division to make an inspection checklist available to every short-term rental applicant identifying the carbon monoxide detector requirements alongside smoke detectors, fire extinguishers, a posted evacuation plan and unobstructed shared stairways.

Covington Code of Ordinances Section 110.31, carbon monoxide alarm devices, with the short-term rental checklist duty at Section 127.17 Checked 2026-08-11.

Louisville-Jefferson County

Louisville makes the alarm a standing duty of the host rather than a condition of construction. Section 115.520 lists what a short-term rental host must ensure: that the property meets the smoke alarm requirements of LMCO Section 94.02, that it has at least one functional carbon monoxide detector installed in an appropriate location as set out in the Kentucky Residential Code, that it has at least one properly maintained and charged fire extinguisher on each habitable floor, and that every sleeping room has at least one operable emergency and rescue opening. The placement standard is the state's, borrowed rather than rewritten, which is what the uniform code requires. What Louisville adds is that the duty runs for as long as somebody is hosting, that it reaches a dwelling nobody has taken a permit for in decades, and that the fire extinguisher and egress conditions travel with it.

Louisville Metro Code of Ordinances Section 115.520, duties of a host, short-term rentals Checked 2026-08-11.

Lexington-Fayette

Lexington writes the same bargain into its licensing chapter and adds two words that matter. Section 13-79 sets the duties of a licensee, requiring that the property comply "at all times" with a list: sufficient smoke detectors installed and in working order under Section 12-1 of the code, at least one functional carbon monoxide detector installed in an appropriate location as set out in the Kentucky Residential Code, and at least one maintained and charged fire extinguisher in an open and easily accessible location on each habitable floor. "At all times" is the operative phrase. It converts a code provision that speaks once, when work is permitted, into a continuing condition of holding the licence, and it puts the extinguisher somewhere a guest can reach rather than merely somewhere on the premises.

Lexington-Fayette Urban County Government Code of Ordinances Section 13-79, duties of a licensee Checked 2026-08-11.

What was checked:Kentucky's building code is mandatory and uniform, which this site has already established from KRS 198B.040(7) and 198B.050 and from the adopting regulation's own preamble. A Kentucky city therefore cannot write construction requirements at all, and all three findings below respect that in the same way: each borrows the Kentucky Residential Code or a national standard for the technical answer and supplies its own duty, its own trigger and its own enforcement. Two of them hang the duty on a short-term rental registration and one on a residential rental property licence. That is worth stating plainly for a reader, because it changes what "compliance" means. The state code speaks at permitted work. A licence condition speaks continuously, for as long as the licence is held, and is checked by whoever issues it. Six municipalities read on 2026-08-11: Louisville-Jefferson County, Lexington-Fayette, Covington, Bowling Green, Owensboro and Paducah. Bowling Green, Owensboro and Paducah carry nothing, each control-tested against terms their own indexes return. Northern Kentucky beyond Covington, the Red River Gorge cabin country and the Lake Cumberland towns were not searched.

Local sweep last reviewed 2026-08-11.

Official Sources & References

815 KAR 7:120, Kentucky Building Code , Necessity, Function and Conformity; Section 1 definitions; Section 2 (building code, accessed 2026-08-08)
The instrument that settles lodging, and it settles it in one sentence: "The 2015 International Building shall be the mandatory state building code for all buildings constructed in Kentucky", subject to three exceptions and no more. The Kentucky amendments in the 2018 Kentucky Building Code supersede any conflicting provision; one- and two-family dwellings and townhouses go to 815 KAR 7:125; manufactured homes go to KRS 227.550 through 227.665. Section 1 defines each of those three terms, and none of the definitions can be stretched over a hotel. The preamble records that KRS 198B.040(7) and 198B.050 require a mandatory uniform code for the construction of all buildings in the state.
Kentucky rendering of the 2015 International Building Code, Section 915 Carbon Monoxide Detection , Section 915.1 and 915.1.1 (building code, accessed 2026-08-04)
Confirms the adopted edition carries the provision and that it reaches lodging. 915.1.1 requires carbon monoxide detection in Group I-1, I-2 and R occupancies and in classrooms in Group E occupancies, and a hotel is Group R-1. Kentucky's rendering omits Group I-4, which the 2015 model text carries. 915.1 governs new buildings and routes existing buildings to Chapter 11 of the International Fire Code.
2013 Kentucky Residential Code Third Edition (DHBC PDF) , R315.2.2 existing-dwelling trigger language, with placement at R315.3 (building code, accessed 2026-02-16)
Cited edition is the 2013 Kentucky Residential Code. The current instrument is the 2018 Kentucky Residential Code, Third Edition, effective 1 August 2024, and the section numbering above was re-read against it on 2026-08-12. The 2013 PDF itself could not be re-fetched, because dhbc.ky.gov refuses connections from this network, as does apps.legislature.ky.gov.
2013 Kentucky Residential Code Third Edition (R315 adoption context) , R315 reference pathway to R315.1 requirements (building code, accessed 2026-02-16)
Supports the installation-reference language. Read R315.1 for the general duty and listing, R315.2.2 for the permit trigger, and R315.3 for placement.
815 KAR 7:125 Kentucky Residential Code adoption , 815 KAR 7:125 (state code, accessed 2026-02-17)
Administrative regulation that adopts IRC-based residential code framework in Kentucky.
815 KAR 7:125 Kentucky Residential Code adoption (administrative scope) , Adoption scope and applicability for one- and two-family dwellings (state code, accessed 2026-02-17)
Additional adoption context for statewide code-enforcement workflow.

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.

Frequently Asked Questions

Which Kentucky code-adoption scenarios trigger mandatory home CO alarms?

Permit-triggered work is the Kentucky route, and the two section numbers are constantly swapped. Kentucky Residential Code Section R315.2.2, Alterations, Repairs and Additions, is the TRIGGER, under which work requiring a permit in a covered dwelling brings the alarm duty with it. Section R315.3 is the PLACEMENT rule that then says where the alarm goes, outside each separate sleeping area in the immediate vicinity of the bedrooms and inside any bedroom holding a fuel-burning appliance. Guidance that cites R315.3 as the trigger has them the wrong way round, and a reader who follows it will look for a permit condition in a rule about position. The adoption is 815 KAR 7:125 for one- and two-family dwellings and 815 KAR 7:120 for everything else.

Are Kentucky rental properties affected by the same code pathway?

A Kentucky rental answers the same code pathway as any other dwelling, and the rental-specific duty, where one exists at all, is local rather than state. The construction layer is uniform and cannot be added to, because KRS 198B.040(7) and 198B.050 make the building code mandatory statewide, so no city can write a stricter carbon monoxide construction rule. What a city can do is attach a condition to a rental licence, and two have. Covington Section 110.31(B)(1)(a) and Louisville Section 115.520 both sit in rental licensing chapters rather than in a building code. On top of that, KRS 383.500 lets a city, county or urban-county government adopt URLTA, and in a URLTA jurisdiction the landlord owes compliance with building and housing codes affecting health and safety; outside one, the allocation is whatever the lease says.

Does Kentucky publish one standalone CO detector penalty statute?

No, and the absence is structural rather than an oversight. Kentucky writes no standalone carbon monoxide statute, so there is no carbon monoxide fine to publish. The duty lives inside an adopted construction code, which means the enforcement is the code's own, a permit that does not pass inspection and an occupancy that does not issue. Where a rental licence carries the condition, as in Covington and Louisville, the penalty is the licensing chapter's rather than the building code's. A reader looking for a dollar figure attached to a missing alarm will not find one at state level.

Are all-electric Kentucky homes automatically outside CO alarm obligations?

Usually yes, and the limb that reopens it is the building rather than the unit. R315 of the Kentucky Residential Code attaches where the dwelling contains a fuel-burning appliance or fireplace, is served by a fuel-burning forced-air furnace, sits in a building containing fuel-burning appliances, or has an attached garage. A detached all-electric house with no attached garage meets none of them. In an apartment building the third limb is the one to check, because it reaches a unit in a building that holds fuel-burning equipment rather than only a unit that holds it, so a shared boiler in a mechanical room can pull an all-electric unit back in. An attached garage does the same whatever the unit burns.

How does Kentucky's answer differ from Tennessee's for an owner on the state line?

Where the duty is written, which changes who a reader has to ask. Kentucky has no carbon monoxide statute at all, so everything runs through an adopted construction code and a permit, and a city cannot add to the construction layer because KRS 198B.040(7) and 198B.050 make it uniform. That is why the Kentucky answer for an existing building so often comes back as nothing until work is done to it. For the neighbouring position, see Tennessee CO detector laws.

Practical CO Detector Guides

Beyond legal requirements, these guides help you choose, install, and maintain CO alarms:

Where to place carbon monoxide detectors, room-by-room placement recommendations
CO detector beeping patterns, what different alarms mean
What to do if your detector goes off, emergency response checklist
CO resources and links, official agencies and safety information