Carbon monoxide alarms are a mandatory requirement for all homes where a new fossil fuel appliance is installed in Northern Ireland, after a change to The Building Regulations (Northern Ireland) 2012 came into operation on 31 October 2012. The Private Tenancies Act, which requires carbon monoxide alarms to be installed in privately rented homes and places a duty on landlords to repair them, received Royal Assent on 27 April 2022.