Vertical city

AT 310 metres, it's London's tallest building and Europe's, too. In skyscraperrich New York and Hong Kong, it is a struggle for recognition but here its solitary, luminous presence dominates the skyline. Ten years ago property developer Irvine Sellar took the idea to architect Renzo Piano, best known for co-designing the Pompidou Centre in Paris. Piano wanted to create "a shard of glass, a spire tower of angled planes of glass that will reflect light and the changing patterns of the sky so that it will change according to the weather and the seasons". Piano also wanted to change the concept of the skyscraper and its function.