How builders rely more on elevators for evacuation in a post-9/11 world

Builders are increasingly relying on advancements in elevator technology for emergencies

Bucking convention, skyscrapers world over have begun relying more on elevators as a means of escape and evacuation during an emergency instead of stairs. The Commercial Observer has examined this trend in a feature out this week that compares buildings trends in Asia and the United States.

Based on the CO’s reporting, two major trends have emerged in the post 9/11 world in relation to skyscraper construction. In Asia, a lot of skyscrapers rely on what a principal at the architecture firm, Gensler described to the CO as, "a system of local and express elevators."

These buildings are designed with what are known as sky lobbies which are essentially large common areas that generally function as an atrium or a coffee shop. People then ride an express elevator from here to one of the landing floors in the building, and then take local elevators to go to their particular floor. In case of an evacuation, people would walk down to the nearest landing floor and take the express elevator to exit.

As a Department of Buildings spokesperson informed the CO, that trend hasn’t quite made it to New York yet. In this city, signage and lights in the building point to the evacuation elevators on the designated gathering floors. In addition, builders are adopting more resilient construction techniques in the city. Many of the new buildings are being built with thick concrete cores which are surrounded by strong protective walls. This not only creates larger and more open office space, but the core area also houses the escape routes and stairwells.

Elevators in some cases are becoming pressurized to prevent the smoke from elevator shafts to spread onto different floors. One and Seven World Trade Center both have such pressurized elevators. A new technology being tested out is the twin elevator system, where two elevators operate in the same shaft but with their own mechanical system and counterweight. This uses less floor space and can move people faster.

from
http://ny.curbed.com/2016/9/1/12752486/skyscraper-construction-safety-elevator-9-11