Safety is always a priority with building industry professionals, especially when designing and building high density buildings. Because skyscrapers were built to withstand enormous pressures from natural or unnatural forces, buildings prior to 9/11 were not designed with mass evacuation in mind. Surely evacuations would take place, but not to the extent that every floor would be impacted by an event.
Since the tragedy, many updates to the International Building Code as well as the International Fire Code have occurred to address the failures of the towers. Of note, buildings over certain height thresholds require wider stairwells and in some cases additional stairwells and emergency elevators. As you can imagine, these additions often require drastic changes to building plans and the ultimate design. In addition to egress, updates to fire alarm wiring, sprinklers, exit signage and security measures have also been adapted to fit the type of world we live in today.
Balancing design, function and safety of super tall structures has come to be a challenge for architects and developers. The competing codes make it difficult to ascertain the exact requirements necessary to construct a safe and efficient building. One World Tower experienced some of these growing pains in its several phases of design. Everything from the structural core, lobby, roof, materials, and set backs are examined to provide maximum safety and efficiency for building users.
As people continue to move back into cities, and our buildings grow even further into the sky, even more stringent safety measures will no doubt grace the code books.