Before 1946 the school was divided into sets; the sets were chosen each term, and each set was named after its leader for that term. Thus in Summer 1941 the sets (and leaders) were: Curtin's (JB Curtin), Musgrave's (JA Musgrave, Head of School), Sturgeon's (RN Sturgeon) and Walker's (GMH Walker).
On return to Hoylake in January 1946, the school was divided into permanently-named houses, making it possible for loyalties to develop, and for rivalries to be continued term after term. These rivalries took solid form in the shelves of silver cups in the Dining Hall, awarded for various individual and inter-house competitions.
The house-names (and colours) remained the same from 1946 until the school's closure in 1985: Chester (gold), Dee (green), Hilbre (red) and Mersey (blue). Each house was the responsibility of a couple of masters, who would encourage and train house teams, and direct house plays.
Prefects were not necessarily chosen to serve in the house to which they had originally been allocated. So a boy who had developed four years of loyalty to Dee might suddenly be switched to Mersey for his last term or two; a little unsettling, but necessary when prefects formed 7%-10% of the school.
The 'house on duty' would reorganise the layout of rooms as necessary: the Dining Hall was used for services and singing-practice on the weekly half-holidays (Wednesday and Saturday), so tables had to be dragged aside, and chairs set in suitable neat rows, then all put back again afterwards; the Museum Block was used for Music Club, Meccano Club, Parliamentary, dancing, and other miscellaneous lectures and gatherings, so the partitions had to be wheeled out of the way, desks dragged aside, chairs lined up suitably for the occasion (including stacking-chairs brought out of various hiding-places), then all put back again afterwards.