Central Saint Giles, London 

The Central Saint Giles complex provides a new attraction to London’s Oxford Street. Renzo Piano has suspended colourful façade elements in front of the individual buildings and therefore introduced a much discussed dash of colour into the heart of the city. The complex, not far from London’s theatre district, comprises a total of 400 000 sqm of office space, more than 100 smart apartments plus a piazza with exclusive restaurants and retailing. Slender columns raise the buildings above the set-back all-glass façades of the ground floors – expressively shaped terracotta elements meeting the practicality of glass architecture.

Jumbo size glass façades provide a contrast to the small-format language of the upper floors. Spanning between horizontal sections top and bottom, it is only the vertical joints between the panes of glass that remain visible. Narrow aluminium bars on the outside discretely continue the verticality of the concrete columns, lending the façade a restrained rhythm. The bars are screwed through the joints to glass fins behind, the front edges of which are bonded by structural silicone to aluminium sections with threaded studs.

Both the insulating glass units outside and the laminated safety glass panes inside – 6 m high and in widths of up to 2.5 m – are extremely heavy. Panes weighing up to almost 1 t had to be transported, rotated and positioned in a very confined space. A minicrane, top-mounted tracks and lifting equipment were needed constantly during erection. And last but not least: even the countless all-glass and revolving doors are not “off-the-peg” models. Worked out down to the tiniest detail, they bear the signature of Renzo Piano, but are nevertheless “made by seele”.