Health and Safety Code section 17926, California Legislative Information was read on September 23, 2026, and every quote on this page came off that page on that day. Fifty states were read the same way for the national comparison.

California Carbon Monoxide Detector Law: Every Home

Q: Where does California say the alarm goes?

The code prints the spot: in a manner consistent with building standards applicable to new construction for the relevant type of occupancy or with the manufacturer's instructions, if it is technically feasible to do so. California is one of 20 states that put a location in writing rather than leaving it to the manufacturer's instructions.

Q: What about buildings that are not houses in California?

California writes separate rules for hotels and motels, what counts as a dwelling unit. Those sections sit beside the residential one rather than inside it, and each is quoted on this page.

Yes

Required in a home

Cal. Health & Safety Code 17926(a)

Yes

Reaches a home already lived in

one of 10 states that do

Covered

In a rented home

one of 28 states that reach a tenancy

In the code

Where the code says to put it

one of 20 states that print a spot

September 23, 2026

Read

off the state’s own published code

The short answer

California requires an alarm in every home, including one already lived in.

California puts the duty on the owner of any existing dwelling unit that has a fossil fuel burning appliance, a fireplace or an attached garage, with no sale, permit or tenancy needed to trigger it, and the deadlines for existing homes have long since passed.

In California the duty attaches to the dwelling itself, so it is on a house that was built, sold and lived in long before the section passed. The trigger the code names is none: the duty is continuous and was phased in by fixed dates, with no sale, permit or tenancy needed.

Every homeReaches a lived in homeRented homesCal. Health & Safety Code 17926(a)read September 23, 2026

The section itself

Cal. Health & Safety Code 17926(a), and what it attaches to

The sentence below is the whole of it. Everything that separates California 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 device, installation in existing dwelling units

Cal. Health & Safety Code 17926(a)

(a) An owner of a dwelling unit intended for human occupancy shall install a carbon monoxide device, approved and listed by the State Fire Marshal pursuant to Section 13263, in each existing dwelling unit having a fossil fuel burning heater or appliance, fireplace, or an attached garage, within the earliest applicable time period as follows: (1) For all existing single-family dwelling units intended for human occupancy on or before July 1, 2011. (2) For all existing hotel and motel dwelling units intended for human occupancy on or before January 1, 2017. (3) For all other existing dwelling units intended for human occupancy on or before January 1, 2013.

Health and Safety Code section 17926, California Legislative Information, read September 23, 2026. Read it at the source

ReachEvery home, including one already lived in
Triggernone: the duty is continuous and was phased in by fixed dates, with no sale, permit or tenancy needed
EffectiveJuly 1, 2011 for existing single family dwelling units and January 1, 2013 for all other existing dwelling units
SourceHealth and Safety Code section 17926, California Legislative Information

The section speaks to the dwelling rather than to something happening to it, which makes it the only shape that reaches a house nobody is building, selling or renting.

Why this state is unusual

California is one of 10 states whose duty follows the dwelling

In the other 25 states that require an alarm, the requirement waits: for a sale, for a permit, for a first build, for a lease. A house standing in one of those states, owned by the same person for twenty years, can sit outside its state’s carbon monoxide section entirely. That is not true here.

The other 9 written the same way are below, with the sentence each one used and the date it took effect, oldest first.

The ten states whose carbon monoxide duty attaches to the dwelling itself, oldest section first.
State	Effective	Citation	The sentence that attaches it
Washington	January 1, 2011 for newly constructed residential occupancies and January 1, 2013 for all other residential occupancies	Wash. Rev. Code 19.27.530	“(1) By July 1, 2010, the building code council shall adopt rules requiring that all buildings classified as residential occupancies, as defined in the state building code in chapter 51-54 WAC, but excluding owner-occupied single-family residences legally occupied before July 26, 2009, be equipped with carbon monoxide alarms. (2)(a) The building code council may phase in the carbon monoxide alarm requirements on a schedule that it determines reasonable, provided that the rules require that by January 1, 2011, all newly constructed buildings classified as residential occupancies will be equipped with carbon monoxide alarms, and all other buildings classified as residential occupancies will be equipped with carbon monoxide alarms by January 1, 2013. (b) Owner-occupied single-family residences legally occupied before July 26, 2009, are exempt from the requirements of this subsection (2). However, for any owner-occupied single-family residence that is sold on or after July 26, 2009, the seller must equip the residence with carbon monoxide alarms in accordance with the requirements of the state building code before the buyer or any other person may legally occupy the residence following such sale.” source
California	July 1, 2011 for existing single family dwelling units and January 1, 2013 for all other existing dwelling units	Cal. Health & Safety Code 17926(a)	“(a) An owner of a dwelling unit intended for human occupancy shall install a carbon monoxide device, approved and listed by the State Fire Marshal pursuant to Section 13263, in each existing dwelling unit having a fossil fuel burning heater or appliance, fireplace, or an attached garage, within the earliest applicable time period as follows: (1) For all existing single-family dwelling units intended for human occupancy on or before July 1, 2011. (2) For all existing hotel and motel dwelling units intended for human occupancy on or before January 1, 2017. (3) For all other existing dwelling units intended for human occupancy on or before January 1, 2013.” source
Ohio	November 20, 2025 (rule); the modified Section 1103.9 begins "On or before January 1, 2019, carbon…"	Ohio Adm.Code 1301:7-7-11 (Ohio Fire Code, Chapter 11), modifying International Fire Code Sections 1101.1 and 1103.9	“2. The provisions of Section 1103.9 shall apply to all existing occupancies identified in Section 1103.9.” source
Illinois	P.A. 94-741, eff. 1-1-07	430 ILCS 135/10	“Every dwelling unit shall be equipped with at least one approved carbon monoxide alarm in an operating condition within 15 feet of every room used for sleeping purposes.” source
Alaska	not printed in the section	Alaska Stat. 18.70.095(a)	“(a) Smoke detection devices shall be installed and maintained in all dwelling units in the state, and carbon monoxide detection devices shall be installed and maintained in all qualifying dwelling units in the state. The smoke detection devices must be of a type and shall be installed in a manner approved by the state fire marshal. The carbon monoxide detection devices must have an alarm and shall be installed and maintained according to manufacturers' recommendations.” source
Iowa	not printed in the section	Iowa Code 10A.518(3)(b)	“Existing single-family dwellings that have a fuel-fired heater or appliance, a fireplace, or an attached garage shall be equipped with approved carbon monoxide alarms.” source
Massachusetts	not printed in the section	M.G.L. c. 148, §26F1/2	“Every dwelling, building or structure, including those owned or operated by the commonwealth, occupied in whole or in part for residential purposes, that: (1) contains fossil-fuel burning equipment including, but not limited to, a furnace, boiler, water heater, fireplace or any other apparatus, appliance or device that burns fossil fuel; or (2) incorporates enclosed parking within its structure shall be equipped by the owner with working, approved carbon monoxide alarms in conformance with the requirements of the board of fire prevention regulations” source
Minnesota	not printed in the section	Minn. Stat. 299F.51, subd. 1 (a)	“Every single-family dwelling and every dwelling unit in a multifamily dwelling must have an approved and operational carbon monoxide alarm installed within ten feet of each room lawfully used for sleeping purposes.” source
New York	not printed in the section	N.Y. Exec. Law 378(5-a)	“Standards for installation of carbon monoxide detectors requiring that every one or two-family dwelling, or any dwelling accommodation located in a building owned as a condominium or cooperative in the state or any multiple dwellings shall have installed an operable carbon monoxide detector of such manufacture, design and installation standards as are established by the council.” source
Wisconsin	not printed in the section	Wis. Stat. 101.647 (3) (a)	“The owner of a dwelling shall install a functional carbon monoxide detector in the basement of the dwelling and on each floor level except the attic, garage, or storage area of each dwelling unit.” source

Where the code says to put it

California writes the location into the code

California writes the spot into the code: in a manner consistent with building standards applicable to new construction for the relevant type of occupancy or with the manufacturer's instructions, if it is technically feasible to do so.

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

in a manner consistent with building standards applicable to new construction for the relevant type of occupancy or with the manufacturer's instructions, if it is technically feasible to do so

(b) With respect to the number and placement of carbon monoxide devices, an owner shall install the devices in a manner consistent with building standards applicable to new construction for the relevant type of occupancy or with the manufacturer's instructions, if it is technically feasible to do so.

California, read September 23, 2026. Read it at the source

In a rented home

What California puts on a landlord and what it puts on a tenant

California puts the job on the owner. The owner installs and maintains, the device must work when the tenant takes possession, and the tenant's duty is to report a fault.

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
Maintainsowner

the owner installs and maintains, the device must work when the tenant takes possession, and the tenant's duty is to report a fault.

(a) An owner or owner's agent of a dwelling unit intended for human occupancy who rents or leases the dwelling unit to a tenant shall maintain carbon monoxide devices in that dwelling unit consistent with this section and Section 17926. ... (c) The carbon monoxide device shall be operable at the time that the tenant takes possession. A tenant shall be responsible for notifying the owner or owner's agent if the tenant becomes aware of an inoperable or deficient carbon monoxide device within his or her unit.

California, read September 23, 2026. Read it at the source

What counts as an alarm

California names the standard the alarm has to meet

California names ANSI/UL 2034 or ANSI/UL 2075, approved and listed by the State Fire Marshal. 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.

What the code provides

California writes the consequence into the section

California writes the consequence into the code: an infraction with a maximum fine of $200 for each offense, after a 30 day notice to correct.

It is quoted on the card above in the sentence it was read from. What a penalty clause says and what an enforcement body does with it are different questions, and only the first is on this page. Nationally 19 states print something inside the section; the rest send a reader to a general enforcement provision.

Buildings that are not houses

The 2 other buildings the California code reaches

What the section covers in California is an existing dwelling unit with a fossil fuel burning heater or appliance, a fireplace, or an attached garage.

Hotels, schools, care homes and childcare buildings are where several legislatures started, and in a few states they are still the only place a carbon monoxide duty appears at all. Each is quoted below under the kind of building it covers.

hotels and motels
existing hotel and motel dwelling units were given until January 1, 2017
Cal. Health & Safety Code 17926(a)(2)
For all existing hotel and motel dwelling units intended for human occupancy on or before January 1, 2017.
Cal. Health & Safety Code 17926(a)(2), read September 23, 2026. Read it at the source
what counts as a dwelling unit
the definition reaches condominiums, lodging houses, dormitories and time shares, and excludes state and local government property
Cal. Health & Safety Code 13262(b)
"Dwelling unit intended for human occupancy" means a single-family dwelling, factory-built home as defined in Section 19971, duplex, lodging house, dormitory, hotel, motel, condominium, stock cooperative, time-share project, or dwelling unit in a multiple-unit dwelling unit building or buildings. "Dwelling unit intended for human occupancy" does not mean a property owned or leased by the state, the Regents of the University of California, or a local governmental agency.
Cal. Health & Safety Code 13262(b), read September 23, 2026. Read it at the source

How California compares

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.

10Every home

4Rented and new

11Permit or new build

8Sale or transfer

6New build only

3Rented only

8None statewide

All fifty states, alphabetical. Reach is what the section speaks to: the dwelling itself, or an event happening to it.
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

A row of tall nineteenth century brick and frame houses on Queen City Avenue in the South Fairmount neighbourhood of Cincinnati, under a clear sky. — Housing this old is the whole question. Ohio is one of ten states whose carbon monoxide section attaches to the dwelling itself, so it reaches these houses as they stand. In most of the country the same section would wait for one of them to be sold, altered under permit or rebuilt. “Queen City Avenue, South Fairmount, Cincinnati, OH (28224745388)”, Warren LeMay, CC0

California carbon monoxide alarm questions

Does California require a carbon monoxide detector?

Does the California requirement apply to an older house?

Yes. California is one of ten states whose section speaks to the dwelling rather than to a sale, a permit or a new build, so the age of the house does not change the answer. The section reads: "(a) An owner of a dwelling unit intended for human occupancy shall install a carbon monoxide device, approved and listed by the State Fire Marshal pursuant to Section 13263, in each existing dwelling unit having a fossil fuel burning heater or appliance, fireplace, or an attached garage, within the earliest applicable time period as follows: (1) For all existing single-family dwelling units intended for human occupancy on or before July 1, 2011. (2) For all existing hotel and motel dwelling units intended for human occupancy on or before January 1, 2017. (3) For all other existing dwelling units intended for human occupancy on or before January 1, 2013."

Where does California say the alarm goes?

Who is responsible in a rented home in California?

What is the penalty in California?

An infraction with a maximum fine of $200 for each offense, after a 30 day notice to correct. The code puts it this way: "(c) (1) Notwithstanding Section 17995, and except as provided in paragraph (2), a violation of this section is an infraction punishable by a maximum fine of two hundred dollars ($200) for each offense. (2) Notwithstanding paragraph (1), a property owner shall receive a 30-day notice to correct."

What about buildings that are not houses in California?

What kind of alarm does California accept?

When was this read?

Carbon monoxide detector laws in every state

Home heating rebatesWhat a state pays toward replacing the fuel burning appliance the alarm is watching, and where the application actually lives.Sidewalk snow removal rulesWho has to clear the walk and by when, read off thirteen statutes and a great many city codes.Leaving a car running unattendedThe winter law that turns out to sit in a theft statute rather than an emissions one.Ground snow load by stateWhat a roof is designed to carry, and the fourteen states that publish their own number.

California read September 23, 2026, off the state’s own published code: Cal. Health & Safety Code 17926(a), 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 California 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.