Originally designed as a high school in 1932, and added to in the 1950s, McCall contained many spaces inappropriate for a middle school program. In addition, the growing middle school population required additional space.

HMFH's renovation design included reconfiguration of teaching spaces to accommodate middle school team clusters with science classrooms, and staff/team support areas. Technology labs were created in spaces once occupied by now-obsolete high school locker rooms. The existing library was converted to classrooms and the addition contains a new media center and classrooms. Because of the building's historic importance to the town, the exterior design of the addition had to meet very strict requirements that it reflect the neo-classical appearance of the original building.

Located near the town center, McCall is often used by the community after school hours. Improvements include a new after-school youth center, renovation of the 800-seat community auditorium, upgrade of the gymnasium, and accessibility improvements.