A series of additions to the museum provided space for staff and projects. The five-story Crowninshield Building, designed with the aid of top consultants and named for du Pont's sister, Louise Crowninshield, housed a library and archives, offices, and state-of-the-art conservation laboratories. Henry Francis du Pont climbed a nearby hill to be sure the building would not block views of the garden and insisted that two full stories be hidden underground. The dedication in May 1969 followed by only a month the death of du Pont. The facility, which many staffers thought ugly, joined the existing South Wing (1957–1959, Victorine and Samuel Homsey), which had provided space for twenty-three professionals plus library, classrooms for the Winterthur Program, a dining room for guests, and a lecture rotunda. Nearby is the latest addition to the museum facilities, the Galleries (1991–1992, Warren J. Cox for Hartman-Cox Architects), built over a creek and repeating motifs from the house, including the clay tile roof and distinctive Winterthur dormers.