The New Plymouth Boys' High School Boarding Houses can cater for up to 190 students living on campus. The boys are divided into two house identities with five different physical buildings offering a range of accommodation from dormitories for juniors to individual rooms for seniors.

The boarding students are supervised by staff who live onsite and are employed by the school during the day for teaching and learning. It allows the team to have a good understanding of a student's academic progress at school. An onsite matron looks after the boy's health and well-being.

Boarding life is very structured with clear expectations of behaviour. The boys have supervised study Monday to Thursday each evening. The school offers seven-day boarding, with the boys allowed to go home each weekend. Many chose to stay in during the weekends because of Saturday sporting commitments.

The school has an on-site laundry, where the boys can drop off laundry on any weekday, and it is usually returned at the end of the day. The commercial kitchen offers three meals via the dining room daily, plus morning and afternoon tea and supper in winter.

Boarders get access to the school facilities like the fitness and conditioning centre after hours, and can take leave to the city on certain days of the week. The boarding staff encourage students to get involved in clubs and activities beyond the school, and where possible, the staff will assist in transportation.