Houstan was scheduled to represent Canada at the 2020 U17 World Cup and U18 FIBA Americas Championship, however, both events were postponed due to the COVID-19 pandemic. Houstan represented Canada at the 2021 FIBA Under-19 Basketball World Cup, where he averaged 17 points, 5.7 rebounds, 2.4 assists, and 2.3 steals per game, to help lead his team to a bronze medal.