The North Tower Addition is a new six-story, 170,000 square foot steel and concrete-framed expansion. The concrete portion of the addition is designed for a total of ten floors and a helistop. The steel portion of the structure was constructed above an existing one-story steel structure. The addition is founded on auger-cast piles and caps. Since the project is classified as high seismic, the structure utilizes Special Reinforced Concrete Shear Walls to provide significant ductility when subjected to earthquake forces.