The church was designed by one of Iowa's early architects, William Foster, who opened his practice in Des Moines in 1857. Foster gave this Gothic Revival church a strong Victorian appearance. The Gothic pointed windows are wide in relation to their height, and even the sanctuary and its various appendages are broad in conjunction with their height. One enters the building, not at the base of its corner tower, but through a small vestibule with gable roof which projects from the right front of the building. In 1963–1965 an open spire of Cor-Ten steel was added to the crenellated tower, but this has been removed. A sympathetic wing with a dormered roof has been added, facing directly onto the sidewalk and street.