Two historic buildings are located on the property of the Convent of the Sacred Heart. The Joseph D. Grant Mansion stands at the intersection of Broadway and Webster Street. To the west of the Grant Mansion stands the second James C. Flood Mansion.

The Grant Mansion, built in 1910, was designed by New York City architects Hiss and Weekes in a Baroque style reminiscent of Manhattan mansions of the early 20th century. Joseph Grant was president of the Columbia Steel Corporation, board chairman of the California-Oregon Power Company and chairman of the Save-the-Redwoods League.

The Grant family sold the building to the convent in 1948.