The Common Rooms are not only physical locations within the college, but they are also communities of students and staff.
The Junior Common Room (JCR) is the undergraduate body of the College with around 750 members. It also refers to the common room itself, consisting of 2 lounges with TV, pool and toastie bar, and the 11th Century Undercroft Bar. The head of the JCR is the Senior Student, who chairs the JCR Executive Committee, which is responsible for the smooth running of the JCR. The JCR Exec is the main link between the undergraduate student body and the College Officers. Other Exec positions include the Vice Senior Student, the JCR Treasurer, Sponsorship & Liaison Officer, Welfare Officer, Social Chair, Services Manager, Bar Chairman, Bar Vice, Livers-Out Rep and Senior DSU Rep. These people are elected annually by the JCR.
The Middle Common Room (MCR) serves the postgraduate members of Castle as a representative and social body. The MCR has a President, and an Executive Committee of six other postgraduates, who fill the roles of Secretary, Treasurer, Steward, Social Secretary, Welfare Officer, and DSU Representative. Members also belong to the JCR. The MCR is located in the 13th Century Maurice E. Tucker Room, near the entrance to the Keep. The Tucker Room is named after the former Master of University College, who donated the use of the room to the MCR.
The Senior Common Room (SCR) consists of academic staff of the University and members from the Durham City and the region. The SCR is a forum for socialising and networking through lunches, dinners, guest nights, wine-tastings and after-dinner talks. The SCR supports the activities of the JCR and MCR through organising inter-common room events which contribute to the academic and social life of the College.