[1] In the 1960s, county leaders decided that the courthouse was too cramped to accommodate the county council in the context of the county council's increasing administrative responsibilities, especially while the courthouse was still acting as a facility for dispensing justice, and therefore chose to acquire additional premises on a site in the north east corner of the Galgorm Castle estate.

[2] The new building, which was designed by Burman Goodall & Partners in the modern style, was completed in 1970.

[3] It was called after Lieutenant Colonel Arthur Chichester, who was Clerk of the Parliaments for Northern Ireland and lived at Galgorm Castle until his death in 1972.

[5] The building was badly damaged in a car bomb attack by the Provisional IRA on 7 October 1972.

[7][8] Approximately 160 civil servants were still employed by the Northern Ireland Assembly in the building as at 1 January 2014.