Designed by Lt Col Beatson RE and built in 1855-6, the offices were originally seven bays wide with the Paper Cartridge Factory visible behind at either side. In the late 19th century the offices were extended to the west and east by eight and six bays respectively, although the extensions are in keeping externally with the original.

The James Clavell Library is named to commemorate the famous author of Shogun, Taipan and King Rat. James Clavell served as an officer in the Royal Artillery during the Second World War and was taken prisoner by the Japanese after being wounded by machine gun fire. He was sent to Java and later transferred to Changi Prison near Singapore. After the war, he took up writing and his first novel, King Rat, was based on his experiences in the POW camp. James Clavell was enormously successful, both as an author and in the world of film-making.