Visitors to the legendary Crystal Palace, built in London for the Great Exhibition of 1851, were said to be awed by its unprecedented expanses of glass – 900,000 square feet of it (84,000 square metres). So much natural light. So spacious. Such openness to the surrounding Hyde Park, including three large elm trees left standing inside.
And that stunning result was achieved on time – with design and construction completed in under a year, and on budget – at a third of the cost of a prior plan for the facility. Key to such success was the use of the curtain wall – a non-load-bearing skin for a structure. As a façade system, curtain walls became viable as structural advances freed exterior walls of the need to bear big loads. Historically they were chosen mainly for aesthetics, but they have proven to enable performance gains too.