Learn about the constraints of place and space on the building design process in this clip from Super Skyscrapers. The architects of London’s Leadenhall Building had a unique challenge. A traditionally-shaped skyscraper would ruin one of the last clean sight lines to London’s most famous landmark, St. Paul’s Cathedral. So, architect Graham Stirk proposed a “wedge” design. This choice posed additional challenges, such as the where to put the bathrooms and elevators when there’s no central core. Thus, the engineers created a new process known as “active alignment,” where the gaps between the steel connections are changed as the building grows.