Carbon Monoxide Alarms in New Mexico Rentals: What an Owner Owes a Resident

Two bodies of law meet on a New Mexico rental and neither one mentions a carbon monoxide alarm.

The technical requirement comes from an adopted code. For a detached one- or two-family dwelling or a townhouse of not more than three stories, the Construction Industries Division adopted the 2021 International Residential Code at 14.7.3.8 NMAC under NMSA 60-13-9(F), and 14.7.3.2 NMAC scopes that rule to construction, alteration, repair, use and occupancy of those buildings. The scope clause lists building types and building work and says nothing about who holds the keys, so a rented house is inside it. Neither "carbon monoxide" nor "R315" appears anywhere in 14.7.3 NMAC, so the model section applies as the 2021 edition prints it.

An apartment building is not on that list. It answers 10.25.5 NMAC, the State Fire Marshal's fire prevention part, which at 10.25.5.2(A) establishes the state's minimum requirements for structures and premises and at 10.25.5.7(E) fixes the operative code as the 2021 International Fire Code. Its only carve-out at 10.25.5.2(B) is the detached houses and townhouses built to the residential code. Across the whole part "915" and "carbon monoxide" each occur zero times against 73 occurrences of "10.25.5", so Section 915.1.1 applies as published and reaches Group R occupancies.

The lease-side law is the Uniform Owner-Resident Relations Act, and its first surprise is vocabulary. New Mexico calls the parties owner and resident. A resident who searches the statutes for landlord duties finds nothing on point and concludes the state has none.

The second surprise is the shape of NMSA 47-8-20. Subsection (A)(1) requires the owner to substantially comply with the requirements of applicable minimum housing codes materially affecting health and safety. Subsection (A)(2) requires repairs and whatever is necessary to put and keep the premises in a safe condition, and (A)(4) requires electrical, plumbing, heating, ventilating and other facilities and appliances to be maintained in good and safe working order. Then subsection (B): "If there exists a minimum housing code applicable to the premises, the owner's maximum duty under this section shall be determined by Paragraph (1) of Subsection A of this section." Where such a code applies, everything in (A)(2) through (A)(6) collapses into compliance with it, and the section becomes a ceiling rather than a list. Whether the residential building code and the fire marshal's rule are minimum housing codes for that purpose is the question a New Mexico case would turn on, and no guidance site raises it.

Two New Mexico owners with the same dead alarm can be standing in completely different places, and neither of them picked which. One is exposed to a misdemeanor that accrues at $500 for every day it continues. The other is exposed to no statutory fine at all. What separates them is not the lease, the rent or the length of the tenancy, and a landlord who has never worked out which side they are on has never priced this risk.

A detached one- or two-family dwelling or a townhouse of not more than three stories with a separate means of egress, built to the New Mexico Residential Building Code, sits under 14.7.3 NMAC. Section R315 of the 2021 International Residential Code then carries the alarm requirement at new construction and at alterations, repairs and additions requiring a permit. Nothing in that adoption reaches backwards: an untouched existing house is outside it, and no sale or transfer provision brings it in.

Everything else rented in New Mexico, an apartment block, a fourplex, a converted commercial floor, falls to 10.25.5 NMAC and the 2021 International Fire Code. Section 915.1.1 reaches Group I-1, I-2, I-4 and R occupancies, and an apartment house is a Group R-2 occupancy. The trigger conditions in Sections 915.1.2 through 915.1.6 are the familiar four: a fuel-burning appliance or fireplace in the unit, a fuel-burning forced-air furnace serving it, a fuel-burning appliance elsewhere in the building with a communicating opening, or an attached private garage.

That is where the asymmetry comes from. NMSA 59A-52-24 attaches to the fire marshal's rule and reaches an apartment owner: a misdemeanor, a fine of not more than $500, and each day the violation continues counted as a separate offense. It travels through 10.25.5.9(K), which disapplies the fire code's own penalty and substitutes it. Nothing equivalent attaches to 14.7.3 NMAC, so the owner of a rented house answers to the permit and inspection machinery of whoever issued the permit and to no statutory daily fine.

One boundary is drawn and not defined. The 10.25.5.2(B) carve-out for houses is withdrawn "for those being used as commercial properties", which is how a short-let house comes back under the fire marshal's rule. The rule does not define commercial use. A long residential tenancy is a residential use of a dwelling on the ordinary reading, and a New Mexico owner letting a house on a term that sits between the two should ask the authority having jurisdiction rather than settle it themselves.

NMSA 47-8-20 is the owner's obligation section, and reading it in order matters because subsection (B) changes what the earlier paragraphs mean.

Paragraph (A)(1) requires the owner to substantially comply with the requirements of applicable minimum housing codes materially affecting health and safety. Note the noun. It is housing codes, where Hawaii writes building and housing laws and Ohio writes building, housing, health and safety codes. New Mexico's carbon monoxide requirement lives in a residential building code and in a fire code, and whether either answers to the description "minimum housing code" is not something the statute settles.

That is why paragraph (A)(2) carries the weight here. It requires the owner to make repairs and do whatever is necessary to put and keep the premises in a safe condition, with no code reference attached. A dead carbon monoxide alarm in a unit with a gas furnace is reachable through (A)(2) whether or not the code question is ever answered. Paragraph (A)(4) adds the maintenance duty for electrical, plumbing, sanitary, heating, ventilating, air conditioning and other facilities and appliances, which catches a hardwired alarm or one the owner supplied and does not catch a plug-in unit the resident brought.

Subsection (B) then sets the ceiling: where a minimum housing code applies to the premises, the owner's maximum duty under the section is determined by paragraph (A)(1). Read that as written and it does two things at once. It gives a resident a code to point at where one exists, and it caps the owner at that code's contents, so (A)(2) stops adding anything the code does not require. A resident in an Albuquerque building governed by a local housing code and a resident in an unincorporated stretch of Sierra County are therefore in different positions, and neither of them is in the position the aggregator summaries describe.

Subsections (C) to (E) handle the clause every landlord wants. For a single-family residence, (C) allows an agreement that the resident perform specified repairs, maintenance tasks, alterations and remodeling, in writing, for consideration, in good faith and not to evade the owner's obligations. For anything else (D) requires a separate signed writing supported by consideration and forbids any diminution of the owner's obligations to other residents. Then (E) says the part that decides the outcome, notwithstanding everything above: an arrangement for the resident to perform the owner's obligations does not diminish those obligations, and the resident's failure to perform them cannot be a basis for eviction or be treated as a material breach. So a New Mexico clause putting the carbon monoxide alarm on the resident survives on paper and does nothing. The owner still owes the duty, and cannot evict for the alarm the clause was written to cover.

Two smaller duties belong in the same file. Subsection (G) requires the owner to give a written rental agreement to each resident before occupancy begins, and subsection (F) requires transparency where utilities are billed across a multi-unit building.

NMSA 47-8-22 lists the resident's obligations, and three of them touch an alarm.

Subsection (A) requires the resident to comply with obligations imposed on residents by applicable minimum standards of housing codes materially affecting health or safety, which mirrors the owner's (A)(1) and inherits the same open question about which codes those are. Subsection (E) requires reasonable use of all electrical, heating, ventilation and other facilities and appliances in the premises.

Subsection (F) is the one to read closely, because New Mexico drafted it wider than most states did. The resident shall not "deliberately or negligently destroy, deface, damage, impair or remove any part of the premises or knowingly permit any person to do so". Hawaii's equivalent reaches wilful acts. Ohio's reaches intentional or negligent destruction. New Mexico writes negligently and adds impair, so the verb covers a device left disabled as well as one taken off the wall. A resident who pulls the battery to stop a chirp and forgets to replace it has done something the statute's words describe, and has weakened their own position under 47-8-27.2 at the same time, because abatement runs on the owner's breach rather than on a condition the resident caused.

The practical instruction is short. Report the fault in writing, keep the device where it is, and if the chirp is a low battery in a unit you are responsible for under a written 47-8-20(C) or (D) agreement, change it and note the date.

Two codes, two section numbers, and one municipal rule that goes further than either.

A rented house, duplex or townhouse under 14.7.3 NMAC reads Section R315 of the 2021 International Residential Code. R315.3 places the alarm outside each separate sleeping area in the immediate vicinity of the bedrooms, and inside a bedroom that contains a fuel-burning appliance or has one in an attached bathroom. One alarm serving a hallway of bedrooms satisfies the sleeping-area rule for all of them; it does not satisfy the in-bedroom trigger, which is counted per room. Section R315.2 holds the two doors into the requirement, new construction and permitted alterations, repairs and additions, and the second catches work that has nothing to do with heating.

An apartment under 10.25.5 NMAC reads Section 915 of the 2021 International Fire Code, which the rule leaves unamended. Detection goes in dwelling units and sleeping units meeting one of the trigger conditions, placement comes from Section 915.2, installation from Section 915.4, and Section 915.5 accepts a detection system in place of individual alarms.

Santa Fe asks for something no other jurisdiction on this site asks for, and a resident of a newer Santa Fe house should know the number. Its Residential Green Building Code, Exhibit A to Chapter VII, applies through Subsection 7-4.2(B)(1) to new single-family dwellings, attached and detached, and Section 11.901.12 requires that at least one alarm be capable of detecting carbon monoxide concentrations as low as 9 parts per million and carry a visible display, on top of placement to NFPA 720, hard wiring with battery back-up where existing electrical lines are accessible, and third-party certification to CSA 6.19 or UL 2034. A conventional alarm listed to UL 2034 is a life-safety device aimed at concentrations that hurt people quickly and stays silent through long exposure well below its thresholds. Santa Fe is asking for an instrument. The section carries an exception where there is no attached garage, no gas-fired appliance within the conditioned space, and a third stated condition, and the city also runs an incentives layer at 7-4.2, so confirm with Santa Fe which measures it enforces as mandatory before relying on the point.

The written rental agreement comes first. NMSA 47-8-20(G) requires the owner to provide one to each resident before occupancy begins, and it is the document that decides which of the 47-8-20(C) and (D) arrangements exist. Read it for any clause about detectors before signing, and remember 47-8-20(E): whatever it says, the owner keeps the duty.

New Mexico writes no move-in alarm inspection into statute and no testing interval into either adopted code. What it writes instead is an entry rule with an unusual door in it, and both parties can use that door.

NMSA 47-8-24 requires the owner to give twenty-four hours written notification of the intent to enter, stating the purpose for entry, the date, and a reasonable estimate of the time frame. Entry is for inspecting the premises, making necessary or agreed repairs, decorations, alterations or improvements, supplying necessary or agreed services, or showing the unit to purchasers, mortgagees, prospective residents, workmen or contractors. In an emergency the owner may enter without consent.

The door is the exception. No twenty-four hour notice is required within seven days of a request by the resident, or where the owner is accompanied by a public official conducting an inspection or by a cable, electric, gas or telephone company representative. Those seven days are the same seven days that run under 47-8-27.1 and 47-8-27.2 before a remedy opens, which means an owner acting on a reported alarm inside the cure period does not need a second notice to get in and fix it. A resident who wants the repair fast should say so in the notice, because the request is what opens the seven-day window for entry.

Where the owner makes an unlawful entry or a lawful entry in an unreasonable manner, or makes repeated demands for entry that harass the resident, the resident may obtain injunctive relief or terminate the rental agreement, and may recover damages in either case.

For the device itself, follow the manufacturer's instructions on testing and read the end-of-life date on the back at move-in. Published service lives run from five to ten years, and our guide to how long carbon monoxide detectors last sets out what each manufacturer states. Photograph the date and the model number on the day you take the keys, because New Mexico gives a resident no statutory move-in inventory to fall back on.

Start from what New Mexico does not have, because it is the thing most residents assume they do.

There is no repair-and-deduct route in the Uniform Owner-Resident Relations Act. NMSA 47-8-27.1 and 47-8-27.2 are the resident remedy sections and both were read for a provision letting a resident have work done and charge it against rent. Neither carries one. A resident who pays a contractor to replace an alarm recovers nothing under either section, and rent short by the invoice amount is rent unpaid. This is the same pattern Montana produced: a state adopting the uniform act, occupying the model's remedial ground, and changing the operative verb.

What sits in that space is abatement, and it has an arithmetic worth doing before deciding whether to use it. Under 47-8-27.2, where there is a violation of 47-8-20 other than a failure in an amenity, the resident gives written notice of the conditions needing repair. If the owner does not remedy them within seven days of the notice, the resident may abate one-third of the pro-rata daily rent for each day from the notice through the day the conditions are remedied. Where the breach renders the dwelling uninhabitable, the rate is one hundred percent of the daily rent for each day from notification until the breach is cured. On rent of $1,500 a month the ordinary rate comes to about $16 a day, so ten days of delay is worth roughly $160. That is the size of the lever, and knowing it in advance is what stops a resident treating abatement as a substitute for a repair that has to happen anyway.

Termination runs on the same seven days. Under 47-8-27.1 the resident gives written notice specifying the breach and stating that the rental agreement terminates on a date not less than seven days after receipt if the breach is not remedied. Damages and injunctive relief for material noncompliance sit alongside it.

Then the choice rule, which has no counterpart in any other state on this site. The remedies are mutually exclusive within a rental period: a resident who abates for a violation cannot also terminate for the same violation in that period, and has to pick. The choice reopens later, because taking one remedy does not preclude an alternate remedy for the same violation in a subsequent rental period. Abatement suits a condition somebody is working on slowly; termination suits one that nobody is going to fix. Choosing wrong costs the other for that month, and a dead alarm is exactly the kind of small, cheap, ignored defect that tempts a resident into abating month after month when the second month should have been a notice to terminate.

The two notices want different things said. A termination notice specifies the acts and omissions constituting the breach. An abatement notice specifies the conditions needing repair. A resident who writes only the second cannot terminate on it, so a notice meant to keep both doors open has to do both jobs on its face.

Retaliation protection under NMSA 47-8-39 is generous and it is dated. An owner may not retaliate by increasing rent, decreasing services, or bringing or threatening an action for possession where, within the previous six months, the resident complained to a government agency about a housing code violation affecting health or safety, exercised a right under the act including a written repair request, or abated rent under 47-8-27.1 or 47-8-27.2. Abating is itself a protected act, which is worth knowing before deciding whether the lever is worth pulling. The owner may still change rent or services at the end of the term where the change is uniform across similar units and not aimed at the particular resident, and a violation gives the resident the remedies in 47-8-48 and a defence to a possession action.

New Mexico attaches a real fine to a carbon monoxide failure and files it where nobody looks for it.

The State Fire Marshal's rule disapplies the International Fire Code's own penalty provisions at Sections 109.4 and 111.4 through 10.25.5.9(K) and (L), and substitutes the penalties in NMSA 59A-52-24 and 59A-52-25. Section 59A-52-24 makes a violation of that article or of rules made under it a misdemeanor punishable by a fine of not more than $500, with each day the violation continues counted as a separate offense. Violating a final cease and desist order costs a further $500 for each day it continues, enforceable by the attorney general in a civil suit brought on the relation of the State Fire Marshal.

Chapter 59A is the Insurance Code. That is where New Mexico files its State Fire Marshal, and it is why a search of the construction titles or the public safety titles finds no penalty and reports the state as having none. The daily accrual is the number that matters rather than the ceiling: $500 is a modest fine, and $500 a day for a quarter is not.

Who it reaches is the part a landlord should settle first. It runs with 10.25.5 NMAC, so it reaches the owner of an apartment building and it does not reach the owner of a detached rented house, whom 10.25.5.2(B) puts outside the rule while the house stays residential. The residential adoption at 14.7.3 NMAC carries no penalty of its own.

Civil exposure runs the other way and reaches both. NMSA 47-8-20(B) expressly leaves existing tort law untouched, so the owner's obligations under the section sit alongside a negligence claim rather than replacing it. A missing alarm the code required, or a supplied alarm left dead after written notice under 47-8-20(A)(4), is documentary evidence in that claim, and the fine is the smaller number in every version of it.