Adelaide House is a two-storey structure with a timber frame, timber clad first floor and ground floor walls of stone.
The ground floor is surrounded by a wide verandah. Of particular importance is the cellar which is part of a unique cooling system. Adelaide House was conceptually designed as a hostel by John Flynn (1880-1951), a Presbyterian minister who was founder and Superintendent of the Australian Inland Mission of the Presbyterian Church in Australia and acknowledged as a founder of the Royal Flying Doctor Service. A particularly favourable fund raising effort in the City of Adelaide in 1919 was commemorated in the hostel's eventual name.