For its first 29 years, St Peter's had two teams: the Dark Blues and the Light Blues competed against one another only in swimming and athletics each year. The School's Founder, Arthur Broadhurst, did not favour the traditional House structure as it had evolved in the British public schools. By 1965, however, it was recognised there was a need for a more formalised system, so each boy was allocated a House colour - blue, red and green - for competition.

Why no yellow? Initially, there was no need. In 1971 St Peter's grew to include a senior school. The Houses were rearranged so that each of the senior boarding houses - Riddet, Oliphant and Broadhurst - took over a colour. Riddet was green, Oliphant red and Broadhurst blue. Preppies were allocated to a senior boarding house for inter-house competitions.

The arrival of a fourth boys' boarding house - School House - created the fourth competitive House - yellow. (in the 1980s, School House boys, form 3 to 7, lived upstairs in the main building, more recently the home of Junior House and interestingly, the present School House for girls).

Competitive house meetings were an interesting and confusing affair by the early1990s. The School had been co-educational since 1988. Girls and Preppies were allocated to one of the boys' boarding housees. So competitive house meetings meant the whole student body had to traipse over the playing fields and squeeze into Broadhurst, Riddet or Oliphant common rooms. The boarding housemasters (as they were called then) took overall responsibility for their competitive house as well. 

Changes were clearly needed, so by the end of 1995 a system of four competitive houses, completely separate from the boys' boarding houses, had been grawn up. Staff, prefects and student council members voted on replacement names. And so Chandler, Swears, Hanna and Thornton were established.

Today's competitive houses compete in six events during the school year, three sporting and three cultural. The prize is the highly sought-after Rosebowl, awarded at prize-giving. Two staff members oversee each team and two Year 13 students are appointed as house leaders.