For the proposed new air traffic control tower at LaGuardia Airport, we explored a series of iterations of the shaft in white concrete beginning as a square in plan and torquing to an octagon to meet the geometry of the cab. The initial studies had the torquing starting from the top. However, the proposed iteration is bringing the torquing to the ground with the upper level splaying to reveal glazing. The solution structurally is to have each side (and lift) precisely cast with equal concrete pours; structurally load bearing and knitting together in the most economic structure evolution. The exterior torquing becomes the exterior and primary structure.
Masayuki Sono, Martin Stigsgaard, Robert Vertes