Barnstable High School never really had a permanent location until 1905, when a building was erected at the present site of Saint John Paul II High School. In 1930, the building was rebuilt. The building was renovated in 1939, due to the increase of students, but it was decided that a new school should be built using land willed to the town by Enoch Cobb.
Modern building
The modern high school building was built from 1956–1957. On September 5, 1957, the new building was officially opened. The original layout included the modern 1200s, 1300s, 1400s, and 1500s. The original layout lacked the present library and cafeteria, which were added later on. The original library was located near the entrance to the modern library. A unique feature of the building were the two cafeterias. One cafeteria was located near on the site of the weight room and athletic office, and the kitchen was also located on the site of the present weight room. The field house was also absent in the original layout. Originally, the high school hosted a vocational school in the modern lower 1200s. The basement of the original building also was built as a bomb shelter, not unusual during the Cold War. The completion of the school did not mean an end to the usage of the old building's facilities. When the school was completed, it lacked athletic fields, which were still under construction. For at least the first year, sporting events were held at the old building. In 1963, the modern 1600s wing was added. The school underwent a renovation in 1976, which added the field house, cafeteria, library and some classrooms nearby. In 1975, the vocational high school closed because of the opening of Cape Cod Regional Technical High School in Harwich. The wing was then turned into the art wing for the school. Mechanical drawing was one of the classes offered in the old shop wing. In 2019, the library completed a $3.5M renovation, which was overseen by librarian Sharon Morgan, who has been the center of some serious allegations of misconduct. $1M of the total $3.5M renovation budget was spent on "Smart Glass" that helps control temperature by brightening or darkening based on the amount of available light outside. The new library consists of comfortable seating areas, moveable modular furniture with plug-ins for laptops and interactive television screens everywhere.