Two tower blocks are nearing completion, the facades of which would seem, at first sight, to be very similar. What the Swiss Re company’s headquarters in London by Foster and Partners and the Westhafen Tower in Frankfurt am Main by Schneider + Schumacher have in common is a circular layout, multi-storey “conservatories” for natural ventilation, and glazed facades divided into triangular or lozenge-shaped elements. The Swiss Re building is almost twice as high as the Westhafen Tower, however, and on closer examination one sees that there are considerable differences in the load-bearing structures, the double-skin facades and the design expression of the two buildings.