In 1962, this became North America's first major multi-story building to utilize pre-cast, pre-stressed concrete. Seven stories in height, the building includes three 45-foot square towers each an assembly of post-tensioned, pre-cast concrete elements. The connecting cores and service towers utilize conventional cast-in-place concrete. In the towers, mechanized services run through openings in the webs of the pre-cast members. The bottom of the pre-cast forms a ceiling grid, leaving the services accessible, yet visually separated from the rooms. The design came about by considering the unique air-handling needs of medical laboratories.