Carbon monoxide alarms — Requirements — Exemptions — Adoption of rules.
RCW 19.27.530
in effect(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. (3) The building code council may exempt categories of buildings classified as residential occupancies if it determines that requiring carbon monoxide alarms are unnecessary to protect the health and welfare of the occupants. (4) The rules adopted by the building code council under this section must (a) consider applicable nationally accepted standards and (b) require that the maintenance of a carbon monoxide alarm in a building where a tenancy exists, including the replacement of batteries, is the responsibility of the tenant, who shall maintain the alarm as specified by the manufacturer. (5) Real estate brokers licensed under chapter 18.85 RCW shall not be liable in any civil, administrative, or other proceeding for the failure of any seller or other property owner to comply with the requirements of this section or rules adopted by the building code council.
(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.
(3) The building code council may exempt categories of buildings classified as residential occupancies if it determines that requiring carbon monoxide alarms are unnecessary to protect the health and welfare of the occupants.
(4) The rules adopted by the building code council under this section must (a) consider applicable nationally accepted standards and (b) require that the maintenance of a carbon monoxide alarm in a building where a tenancy exists, including the replacement of batteries, is the responsibility of the tenant, who shall maintain the alarm as specified by the manufacturer.
(5) Real estate brokers licensed under chapter 18.85 RCW shall not be liable in any civil, administrative, or other proceeding for the failure of any seller or other property owner to comply with the requirements of this section or rules adopted by the building code council.
Source: WA Statutes (Official Site)URL: https://app.leg.wa.gov/RCW/default.aspx?cite=19.27&full=trueFetched: 6/29/2026