Carbon Monoxide Law for State of Washington SOLD HomesState of Washington New Carbon Monoxide Law for Sold HomesEffective April 1, 2012 the new code requires a property owner to install carbon monoxide alarms when alterations, repairs or additions requiring a permit or when one or more sleeping rooms are added or created.Requires the Seller of any owner-occupied single-family residence to equip the residence with carbon monoxide alarms before a buyer or any other person may legally occupy the residence following the sale. This requirement applies to all single family residences, including single family homes, condominiums, and manufactured/mobile homes. March 29 2012 - Spokane22YesReport a ProblemProblemSelect oneOffensive contentIrrelevant contentSpam (pure self-promotion)OtherDetailsYour emailPlease enter a valid email address.Submit CancelContent flaggedWe will review this content. Thanks for helping make the site more useful to everyone. To learn more, read Zillow's Good Neighbor Policy.We're sorry. This service is temporarily unavailable. Please come back later and try again.