There are two dormitories in the Southwell Boarding House. The boys’ dormitory called "Rutherford" is named after the brother of Mrs H G Sergel, Lord Rutherford of Nelson. The girls’ dormitory, named "Oliver" is named after the first student to be enrolled at Southwell School.
Both of these dormitories are divided into smaller squad areas, with each squad being made up of four bunk beds. Squads are made up of mixed age groups, with a senior student appointed to lead their squad who assists boarding house staff with ensuring that daily routines are carried out.