Between the years of 1911 and 1920, the nuns served as faculty and taught without being paid. They supported the operational expenses of the school by selling needlework and teaching music. In 1919, the school had outgrown its building at the St. Vincent Seminary site at Lucas and Grand Avenues. The school moved to the Hayes Mansion on Newstead at the corner of Lindell. In 1921, the Hayes Mansion was moved to make room to build a new larger structure designed by architect Henry P. Hess. This structure was completed in 1922 and remains the main building for Rosati-Kain. In 1941, the gymnasium, cafeteria, and music room were added to the property with funding raised by the Alumnae Association.