The House System at RBAI dates from 1926 when the Principal, Mr. Geoffrey Garrod, considered that as the School's numbers increased to over 600 boys, much could be gained from organizing sports and other activities on a House basis. Healthy rivalry would be generated between the Houses and the boys would have a smaller entity, the House, on which to focus their loyalties. Garrod also hoped that by being part of smaller groups, boys would become more conscious of the importance of the whole School community, because as members of a House they would not feel insignificant individuals in a very large single community. There would also be the additional benefit that boys, the majority in fact, who were not talented enough to represent the School against other schools in a variety of sports and activities, would have the opportunity to do so within the very competitive atmosphere of House competitions. Another benefit would be that much of the onus, in terms of the running of the Houses, would fall on the shoulders of the pupils themselves, and so would provide an important learning experience, involving leadership and initiative.
Initially there were four Houses, each of which was named after a well-known person associated with the School. They were Dill (Sir Samuel Dill, academic), Kelvin (Lord Kelvin, scientist), Larmor (Sir Joseph Larmor, scientist), Pirrie (Lord Pirrie, entrepreneur and benefactor). Later two more Houses were included. They were Jones (R.M. Jones, Principal 1898-1925) and Stevenson (Joseph Stevenson, School Secretary 1807-1837).
The House structure survives to the present day. As well as continuing to provide the framework for the House Championship which embraces competition between the Houses in over a dozen sports and activities, it is also the framework for pastoral care at RBAI. Pastoral care is a fundamental aspect of life at RBAI for the pupils and provides a necessary support to the academic curriculum of the School. The pastoral team at RBAI is headed by the Dean, Mr. ET Foster, supported by the six Senior Housemasters and thirty Form Tutors.