Boarding fosters a sense of independence and self-confidence vital to success in later life. Boarding provides for the development of personal and communal responsibilities and boarders experience a holistic education incorporating academic, social and sporting experiences. Boarders receive tremendous support from each other leading to lifelong friendships.

Completed in 1991, Rostrevor College's Boarding House has set new standards for the welfare and pastoral care of boarders in South Australia, while retaining the tradition of Rostrevor's long association with residential care of Australian and overseas students.

The Boarding House is a large, well resourced building providing accommodation for 75 boys. Rooms vary from semi-divided seven bed dormitories for students in Years 7-10, to single bedrooms for students in Years 11 and 12.

The building incorporates kitchen, dining and laundry facilities as well as spacious television and common rooms for indoor recreation.

When not returning home, weekends for Rostrevor boarders are busy with co-curricular activities and social events organised by a caring staff.