On the local level he was a member of municipal council of Skien Municipality from 1945 to 1959 and 1963 to 1971, serving the last four years as deputy mayor. He was also county mayor of Telemark county from 1967 to 1971. He chaired the county party chapter from 1963 to 1968, and was a member of the national party board from 1963 to 1979. He was County Governor of Telemark from 1976 to 1987.[1]
Outside politics Berrefjord was a jurist. He graduated as cand.jur. in 1941, and participated as a judge in the Legal purge in Norway after World War II. He later worked as a district attorney in Telemark and as a presiding judge.[1]