“It’s quite astonishing to see a structure so pure,” says Hezi Mena, senior vice president of building structures at WSP in New York. “We tried to simplify the structure as much as possible so as not to conflict with the architect’s vision.”
The structural solution developed by the WSP team does have a pleasing simplicity, though this belies the extensive testing and refinement that went into developing it. 432 Park Avenue is made of two high-strength concrete tubes. The interior tube forms the building’s core, measuring 9m x 9m, containing the lifts and egress stairs. This is the backbone of the building. Its reinforced-concrete walls impart considerable stiffness, their thickness varying from 760mm at the base to 300mm at the top.
The outer tube is the tower’s perimeter beam-and- column frame, which is also incredibly stiff, even with the windows punched through it. At every 12th floor these tubes are joined by stiffening beams, accommodated in the double-height plant rooms to avoid encroaching on the apartments themselves. In fact, WSP has managed to remove all interior columns, giving the occupants complete flexibility in how the living spaces are configured.