The cathedral shares its historic designation with the parish rectory and its former convent and school building. The rectory, which is adjacent to the cathedral on the north, was built around 1870. The three-story brick dwelling is considered the finest example of the Italianate style in the Cathedral District. The house features a low hipped roof, paired brackets on the eaves, simple window hoods, and an entrance canopy. The main entrance is flanked by side lights and it has a fan light above. The ironwork detailing and the doors were originally on the mansion of A.A. Cooper, which was named Greystone and was torn down in the late 1950s.