The church was built in 1916–17 and was designed by noted Pittsburgh-based ecclesiastical architect John T. Comès.

[6] In 2020, the university announced plans to demolish the church in order to build a new 10-story health science facility.

[8] St. Agnes is constructed from brown brick and concrete with stone and terra cotta ornamentation including a large, stylized rose window which incorporates a relief depicting the Crucifixion.

[1] The design of the church was described by PHLF architectural historian Walter C. Kidney as "acknowledging no one historic style—Byzantine and Romanesque are both suggested—and original in its rose window and Crucifixion.

[1] The interior is also decorated with a series of murals painted in 1931 by Felix Lieftuchter with the assistance of two Carlow art students.