William previously served on the CHA board for three years as a representative of North Ayrshire Council. He has now retired from his role as a local councillor. He joined the board of Cunninghame Housing Association in February 2018. William was elected as Chairperson of the DevelopmentSubCommittee in 2018 and continues to keep this position. He also serves on the Housing and Property Services & Audit Committees.
William was first elected to North Ayrshire Council in 2007 and became Deputy Leader of SNP Group. In May 2012 he was appointed as Leader of North Ayrshire Council. He later stood for the council on the convention of Scottish Local Authorities (COSLA) for four years. Which was before being elected as Lead of the SNP Scottish Leaders Group of COSLA in 2015.
As a Chemical Engineering graduate of Strathclyde University, he taught mathematics in a number of secondary schools. He was latterly Depute Headteacher at Auchenharvie Academy, Stevenston for eight years.