Top to bottom, this iconic project is replete with innovative designs to meet the demands of the architectural vision of Philip Johnson. From the ground floor to the roof, unimpeded spaces were needed, so post-tensioned slabs were designed to span up to 60 feet. Column-free spaces at the ground level were achieved by inverting the traditional structure of a building and hanging all the interior columns from long-span trusses and plate girders comprising the roof framing. At the building’s foundations, excavation extended 30 feet below the water table, necessitating construction of the city’s first mat foundation to resist the hydrostatic uplift pressure of over 1000 pounds per square foot.