Willis Building (London) 2004 and 2008 under the management of Mace and represented a significant addition to the City of London skyline, becoming its fourth-tallest building after Tower 42, 30 St Mary Axe and CityPoint. The core was topped out in July 2006 and the steelwork completed in September that year. Cladding began in July 2006 and the structure was externally completed by June 2007. It was internally fitted out and officially opened in April 2008. The building was the first in a wave of new tall towers for London's primary financial district. Others included The Pinnacle, the Leadenhall Building and the Heron
30 St Mary Axe than the old Exchange on the site. The site was special because it needed development, it was not on any of the "sight lines" (planning guidance requires that new buildings do not obstruct or detract from the view of St Paul's dome when viewed from a number of locations around London), and it had housed the Baltic Exchange. The plan for the site was to reconstruct the Baltic Exchange. GMW Architects proposed a new rectangular building surrounding a restored exchange: it would have the type of large floor plan that banks liked. Eventually, the planners realised that the exchange was