The characteristic San Silvestre spirit depends greatly on the House system following the British tradition, each house having its own emblematic colour. The House system starts in Second Grade. Each student belongs to one of four Houses: Conroy, Evans, Hope or Kufal. House membership is inherited from one generation to the next and all members of one family belong to the same House. Each House is directed by a House Captain and a House Prefect, under the leadership of the Head Girl, all of whom are Form V pupils. The House Captain is in charge of the main organisation, with the help of her teachers and peers.
The system of Housemarks is applied to academic work, effort, sports, conduct and special projects held during the year, thus promoting healthy competition and also encouraging teamwork.