Carbon Monoxide Detector Laws by State

The first number is the one every article prints, and on its own it reads as a duty that follows the building. In most states it does not. It follows an event. 25 of the 42 attach the requirement to a permit, a sale, a transfer or a first construction, which means a house built before the section passed and not sold since sits outside it.

10 states wrote the duty against the dwelling itself: Alaska, California, Illinois, Iowa, Massachusetts, Minnesota, New York, Ohio, Washington and Wisconsin. In those the section speaks to a house as it stands, with nothing happening to it. That is a different kind of law, which is why it is a different colour everywhere on these pages rather than the top of a scale.

8 states have no statewide section at all: Arizona, Kansas, Mississippi, Missouri, Nevada, North Dakota, South Dakota and Wyoming. That is an answer rather than a gap. In those states the requirement, where there is one, comes from the building code a county or a city adopted, and that is a local question a state page cannot answer.

This is the half of the subject that gets flattened. A state whose section reads “upon sale or transfer” has a carbon monoxide alarm law, and it has nothing to say to somebody who has lived in the same house for twenty years. A state whose section reads “new construction and alterations requiring a permit” reaches the same house only when somebody pulls a permit on it.

The triggers below are the codes’ own. They fall into four shapes, and the table is grouped by them: a rental, a permit or an alteration, a sale or transfer, and a first build. Nobody coordinated this, which is why two neighbouring states can both appear in every roundup as requiring an alarm and mean entirely different things by it.

The other thirty leave it to the manufacturer’s instructions and to whichever code the building was inspected under. Among the twenty that did write one, no two rules are quite the same sentence: some name a distance from a sleeping area, some name every area giving access to bedrooms, some name a storey.

The rules are in the states’ own words below, with the ones reaching every storey first. Summarising twenty different sentences into one is how a page ends up wrong in nineteen states at once, so none of them is summarised.

This is the reading most often reported wrong, because a roundup that counts building code adoptions as state law will put several of these states in the required column. What was read in each is named below, alongside the link, so the absence can be checked rather than taken.

A state with no statewide section is not a state where nothing applies. Counties and cities adopt building codes on their own schedules, and several large ones in these eight states have adopted a code that carries a carbon monoxide provision. That is a local question, and it is the reason the state pages for these eight say what they say and stop.

Ordered by what the section touches rather than by name, so the states whose duty follows the dwelling sit at the top and the 8 with nothing statewide sit at the bottom. The order is a finding in itself: it does not track how cold a state gets, and it does not track how much of its housing stock burns gas.