FORM AND STRUCTURE
The 88,000m 2 of offices, retail and public space in KPF's development are mainly contained in a tower of sheared cones, filleting to tapered planes. The canopy derives from tangential arcs unwrapped parametrically along the facade planes. The skin is set out as a repeating 1.5m module from the base vector of the building, resulting in overlapping shear on the facade.
Each set of panels is also tilted parametrically in relation to the design surface, hence the nickname 'snakeskin'. Primary structure is governed by the demands of the cladding, producing a series of columns that are straight but never vertical. Perimeter stability is provided by a Vierendeel tube, stiffened (but only where necessary) by diagonal bracing elements, linked into continuous spiral lines or chains. The ventilated cavity facade has a thermally broken, segmented inner skin; the cavity is naturally ventilated from the outside. The double-glazed inner skin provides a thermal and weather-tight barrier.
Solar-control blinds are located within the tower's facade. The natural-ventilation facade is part of a series of low-energy design elements within the scheme, including biomass CHP, bore holes, PVS and maximisation of daylight to reduce the need for artificial lighting.