Colorado CO Detector Laws: The Sale Triggers It
Colorado requires an alarm when the house changes hands.
Colorado requires an alarm when the house changes hands.
Colorado requires an operational carbon monoxide alarm within fifteen feet of the entrance to each room lawfully used for sleeping in a single family or multi family dwelling that has a fuel fired heater or appliance, a fireplace, or an attached garage, and the duty attaches to an existing home when it is offered for sale or transfer, when permitted interior alterations, repairs, appliance replacements or additions occur, or when a rental changes tenants.
In Colorado the duty attaches at a closing, which means a house can sit for forty years without ever meeting it. The trigger the code names is the sale or transfer of an existing dwelling, and separately a permitted alteration or a change of tenant occupancy.
C.R.S. 38-45-102, and what it attaches to
The sentence below is the whole of it. Everything that separates Colorado from the state across the river sits inside that sentence and inside the clause that conditions it, which is why it is reproduced rather than summarised.
A requirement and the event it waits for are two different facts, and a roundup that carries the first without the second is how the same state gets described as strict and as lax in the same week. Both are on the card, with the citation, the title the code gives the section and the link the sentence was read from.
The section
Carbon monoxide alarms in single-family dwellings - rules
C.R.S. 38-45-102
Notwithstanding any other provision of law, the seller of each existing single-family dwelling offered for sale or transfer on or after July 1, 2009, that has a fuel-fired heater or appliance, a fireplace, or an attached garage shall assure that an operational carbon monoxide alarm is installed within fifteen feet of the entrance to each room lawfully used for sleeping purposes or in a location as specified in any building code adopted by the state or any local government entity.Colorado Revised Statutes 2026, Title 38, Property - Real and Personal, Office of Legislative Legal Services, Colorado General Assembly, read September 23, 2026. Read it at the source
- ReachWhen the house changes hands
- Triggerthe sale or transfer of an existing dwelling, and separately a permitted alteration or a change of tenant occupancy
- EffectiveMarch 24, 2009, with the duty attaching to dwellings offered for sale or transfer on or after July 1, 2009
- SourceColorado Revised Statutes 2026, Title 38, Property - Real and Personal, Office of Legislative Legal Services, Colorado General Assembly
A conveyance is the event, so the alarm arrives with a new owner and the section says nothing to the one who stayed put.
In Colorado the requirement attaches to the sale or transfer of an existing dwelling, and separately a permitted alteration or a change of tenant occupancy
In Colorado the duty attaches at a closing, which means a house can sit for forty years without ever meeting it. The trigger the code names is the sale or transfer of an existing dwelling, and separately a permitted alteration or a change of tenant occupancy.
This is the reading that decides whether the law is speaking to a particular house. 10 states wrote the duty against the dwelling itself and 25 wrote it against an event, and a national article that prints only the first number reads as though every one of the 42 belonged to the first group. The 25 triggers are below, grouped by shape.
| State | Waits for | The trigger the code names |
|---|---|---|
| Alabama | Permit or new build | residential construction governed by the adopted residential code |
| Arkansas | Permit or new build | work governed by the adopted residential code, since the statutory requirement was repealed in 2013 |
| Hawaii | Permit or new build | building, altering, replacing or repairing a dwelling under the State Residential Code |
| Indiana | Permit or new build | a permitted alteration, addition or complete replacement of the electrical system, and the construction of a new dwelling |
| Michigan | Permit or new build | initial construction of the dwelling, a renovation of an existing dwelling for which a permit is required, or the addition or creation of a bedroom |
| New Mexico | Permit or new build | construction, alteration, repair, replacement or a change of occupancy that is subject to a Construction Industries Division permit |
| Oklahoma | Permit or new build | residential construction, alteration, replacement or repair covered by the statewide minimum residential code |
| South Carolina | Permit or new build | construction under the residential code the state adopts |
| Tennessee | Permit or new build | building a dwelling, changing an existing building over to a dwelling, or adding thirty square feet or more of interior space |
| Texas | Permit or new build | construction, alteration, remodeling, enlargement or repair of a residential structure inside a municipality |
| Utah | Permit or new build | building, altering, remodeling or repairing a dwelling under the state construction code |
| Colorado | Sale or transfer | the sale or transfer of an existing dwelling, and separately a permitted alteration or a change of tenant occupancy |
| Louisiana | Sale or transfer | the sale or lease of the dwelling, and separately the professional installation of a home generator |
| Maine | Sale or transfer | acquiring a single family dwelling or multiapartment building by sale or exchange, with a separate continuous duty on multifamily units and rentals |
| Nebraska | Sale or transfer | a sale or transfer, a permitted interior alteration, construction on or after January 1, 2017, or a change of tenant occupancy |
| New Jersey | Sale or transfer | a sale, a lease, or any other change of occupancy of a dwelling unit in a building with fewer than three dwelling units |
| Oregon | Sale or transfer | conveying fee title or transferring possession under a land sale contract, and separately the start of a new tenancy |
| Rhode Island | Sale or transfer | the transfer of title to an occupied residential property, with a separate duty on new construction and conversion |
| Vermont | Sale or transfer | for a single family house, being constructed or transferred by sale or exchange; for condominiums, multiple unit dwellings and other residential buildings the duty is continuous |
| Connecticut | New build only | a building permit for new occupancy issued on or after October 1, 2005 for a new one or two family residential building; the certificate of occupancy is withheld until the equipment is certified |
| Florida | New build only | constructing a building or building an addition onto one |
| Georgia | New build only | building a dwelling unit |
| Idaho | New build only | taking out a building permit in a city or county that runs a building code enforcement program |
| Kentucky | New build only | constructing a single family dwelling, two family dwelling or townhouse |
| Virginia | New build only | a building permit application for new construction submitted on or after the code's effective date |
Colorado writes the location into the code
Colorado writes the spot into the code: within fifteen feet of the entrance to each room lawfully used for sleeping purposes or in a location as specified in any building code adopted by the state or any local government entity.
The rule is quoted below in the code's own words. Nationally 20 states print one and 5 of those reach every storey rather than the sleeping floor alone, and no two of the 20 are quite the same sentence.
Where the code puts it
within fifteen feet of the entrance to each room lawfully used for sleeping purposes or in a location as specified in any building code adopted by the state or any local government entity
shall assure that an operational carbon monoxide alarm is installed within fifteen feet of the entrance to each room lawfully used for sleeping purposes or in a location as specified in any building code adopted by the state or any local government entity.Colorado, read September 23, 2026. Read it at the source
What Colorado puts on a landlord and what it puts on a tenant
Colorado splits the job: the owner puts the alarm in and the tenant keeps it working. The owner replaces an alarm before a new tenancy and after notice, the tenant keeps, tests and maintains it.
The split matters because the two halves are enforced differently: an installation duty runs against the owner and a maintenance duty commonly runs against whoever is living there. Where the section names no party, the card says so rather than filling the silence with the commonest answer. 28 states of the fifty reach a tenancy at all.
In a rented home
- Installsowner
- Maintainstenant
the owner replaces an alarm before a new tenancy and after notice, the tenant keeps, tests and maintains it.
(3) (a) Notwithstanding any other provision of law, the owner of any rental property specified in subsections (1) and (2) of this section shall: (I) Prior to the commencement of a new tenant occupancy, replace any carbon monoxide alarm that was stolen, removed, found missing, or found not operational after the previous occupancy; (II) Ensure that any batteries necessary to make the carbon monoxide alarm operational are provided to the tenant at the time the tenant takes residence in the dwelling unit; (III) Replace any carbon monoxide alarm if notified by a tenant as specified in paragraph (c) of subsection (4) of this section that any carbon monoxide alarm was stolen, removed, found missing, or found not operational during the tenant's occupancy; and (IV) Fix any deficiency in a carbon monoxide alarm if notified by a tenant as specified in paragraph (d) of subsection (4) of this section. (b) Except as provided in paragraph (a) of this subsection (3), the owner of a single-family dwelling or dwelling unit in a multi-family dwelling that is used for rental purposes is not responsible for the maintenance, repair, or replacement of a carbon monoxide alarm or the care and replacement of batteries for such an alarm. (4) Notwithstanding any other provision of law, the tenant of any rental property specified in subsections (1) and (2) of this section shall: (a) Keep, test, and maintain all carbon monoxide alarms in good repair;Colorado, read September 23, 2026. Read it at the source
Colorado names the standard the alarm has to meet
Colorado names the national fire protection association's standard 720. A combination smoke and carbon monoxide alarm is accepted.
38 states of the fifty name a standard and 16 say in writing that a combination smoke and carbon monoxide alarm satisfies the requirement. Where a state named none, approval belongs to the code the building is inspected under, which is a local reading rather than a state one.
The same question in the other forty nine
42 states require a carbon monoxide alarm in a home and 8 have no statewide section for one. Of the 42, 10 reach a home already lived in, 25 wait for a sale, a permit or a first build, and 28 reach a rented home.
The bar splits the fifty by what their section touches, and the table beneath it puts them in alphabetical order for finding a particular one. Neither order tracks how cold a state gets.
| State | Reach | Rented homes | Placement rule | Citation |
|---|---|---|---|---|
| Alabama | Permit or new build | No | No | Ala. Admin. Code r. 305-2-4-.09 (Residential Building Codes), adopted by the Alabama Energy and Residential Codes Board under Code of Ala. 1975, Sections 41-23-80 through 41-23-85 |
| Alaska | Every home | Yes | Yes | Alaska Stat. 18.70.095(a) |
| Arizona | None statewide | No | No | No section |
| Arkansas | Permit or new build | No | No | 12 CAR pt. 15, Arkansas Fire Prevention Code, 2021 Edition, Volume III |
| California | Every home | Yes | Yes | Cal. Health & Safety Code 17926(a) |
| Colorado | Sale or transfer | Yes | Yes | C.R.S. 38-45-102 |
| Connecticut | New build only | No | No | Conn. Gen. Stat. §29-292 |
| Delaware | Rented only | Yes | No | 16 Del. C. 6602C |
| Florida | New build only | Yes | Yes | Fla. Stat. 553.885 |
| Georgia | New build only | No | No | Georgia State Amendments to the International Residential Code (2024 Edition), Section R311 Carbon Monoxide Alarms, revising Section R311.2.1, adopted by the Department of Community Affairs under the Uniform Codes Act, O.C.G.A. Section 8-2-20 et seq. |
| Hawaii | Permit or new build | No | No | Haw. Rev. Stat. 107-25, with the code adopted under it |
| Idaho | New build only | No | No | Idaho Code 39-4116(2)(b), with the code itself defined at 39-4109(1)(b) |
| Illinois | Every home | Yes | Yes | 430 ILCS 135/10 |
| Indiana | Permit or new build | No | No | 675 IAC 14-4.4-27 (2020 Indiana Residential Code, amending Section R315.2.2 of the 2018 International Residential Code) |
| Iowa | Every home | Yes | No | Iowa Code 10A.518(3)(b) |
| Kansas | None statewide | No | No | No section |
| Kentucky | New build only | No | No | 815 KAR 7:125, promulgated under KRS 198B.040(7) and 198B.050 |
| Louisiana | Sale or transfer | Yes | No | La. R.S. 40:1581 |
| Maine | Sale or transfer | Yes | Yes | 25 M.R.S. §2468 |
| Maryland | Rented and new | Yes | Yes | Md. Code, Public Safety § 12-1104 |
| Massachusetts | Every home | Yes | No | M.G.L. c. 148, §26F1/2 |
| Michigan | Permit or new build | Yes | Yes | MCL 125.1504f (Stille-DeRossett-Hale Single State Construction Code Act, 1972 PA 230, Sec. 4f; the "Overbeck law") |
| Minnesota | Every home | Yes | Yes | Minn. Stat. 299F.51, subd. 1 (a) |
| Mississippi | None statewide | No | No | Senate Bill 2378, 2014 Regular Session, Section 1 |
| Missouri | None statewide | No | No | No section |
| Montana | Rented only | Yes | No | Mont. Code Ann. 70-24-303(1)(g) |
| Nebraska | Sale or transfer | Yes | Yes | Neb. Rev. Stat. 76-604 |
| Nevada | None statewide | No | No | No section |
| New Hampshire | Rented and new | Yes | No | RSA 153:10-a |
| New Jersey | Sale or transfer | Yes | No | N.J.S.A. 52:27D-133.3 |
| New Mexico | Permit or new build | No | No | 14.7.3 NMAC, 2021 New Mexico Residential Building Code |
| New York | Every home | Yes | No | N.Y. Exec. Law 378(5-a) |
| North Carolina | Rented and new | Yes | Yes | N.C. Gen. Stat. § 42-42(a)(7) |
| North Dakota | None statewide | No | No | N.D. Admin. Code 45-18-01-04 |
| Ohio | Every home | Yes | Yes | Ohio Adm.Code 1301:7-7-11 (Ohio Fire Code, Chapter 11), modifying International Fire Code Sections 1101.1 and 1103.9 |
| Oklahoma | Permit or new build | No | No | OAC 748:20-6-1 |
| Oregon | Sale or transfer | Yes | Yes | Or. Rev. Stat. 105.838 |
| Pennsylvania | Rented only | Yes | Yes | Carbon Monoxide Alarm Standards Act, Act of Dec. 18, 2013, P.L. 1229, No. 121, section 4 |
| Rhode Island | Sale or transfer | Yes | Yes | Rhode Island Life Safety Code, 450-RICR-00-00-8, §24.6.3.1 (adopted under R.I. Gen. Laws §23-28.1-2) |
| South Carolina | Permit or new build | No | No | S.C. Code Regs. R.8-1200 (2021 International Residential Code as adopted), promulgated under S.C. Code Ann. Section 6-9-40 and Section 6-9-50 |
| South Dakota | None statewide | No | No | No section |
| Tennessee | Permit or new build | No | No | Tenn. Comp. R. & Regs. 0780-02-23-.02 (Adoption by Reference), Division of Fire Prevention, under T.C.A. Section 68-120-101(a), (b), and (d) |
| Texas | Permit or new build | No | No | Tex. Loc. Gov't Code 214.212 |
| Utah | Permit or new build | No | No | Utah Code 15A-2-103(1)(b) |
| Vermont | Sale or transfer | Yes | Yes | 9 V.S.A. §2882 |
| Virginia | New build only | Yes | Yes | 13VAC5-63-240 (Virginia Construction Code, Section 915 as amended), adopted under Va. Code § 36-99 |
| Washington | Every home | Yes | Yes | Wash. Rev. Code 19.27.530 |
| West Virginia | Rented and new | Yes | Yes | W. Va. Code § 15A-10-12 |
| Wisconsin | Every home | Yes | Yes | Wis. Stat. 101.647 (3) (a) |
| Wyoming | None statewide | No | No | No section |
Colorado carbon monoxide alarm questions
Carbon monoxide detector laws in every state
Colorado read September 23, 2026, off the state’s own published code: C.R.S. 38-45-102, as part of a reading of all fifty compiled September 23, 2026. Every quotation above is reproduced in the source’s own wording and links back to the document it was read from. Legislatures amend these between sessions, and a county or city building code can reach a building the state code does not, so the link beside a quote is what governs on the day. What Colorado wrote is what this page carries: the duty, what it attaches to, where the code puts the alarm, what it says about a rented home, and the sentence it set.