The parish school first met in the basement of the 1850s church, but when the debt on that building was finally liquidated in 1874, construction was begun on this building next door. C. C. Kemble was chosen as architect and received $475.58, or 2.5 percent of the total cost, for his work. Kemble's three-story brick building measures 123 feet by 41 feet, with its narrow, gable end facing the street. The first and second floors were divided into large classrooms, while a spacious auditorium hall, measuring 90 feet by 40 feet and frescoed by a Pittsburgh artist named Vogel, occupied the major portion of the third floor.
Kemble's gable-ended facade is a wellcomposed Rundbogenstil essay. All decorative motifs, as well as the basic wall surfaces, are executed in brick and include prominent hood molds and decorative belt courses. The cornice is particularly massive and ornate, with raking and corbeled arcades forming its lowest member.