Following the collapse of the Twin Towers, building laws and practices for high-rise buildings in
New York City were revised. Tall buildings must
now incorporate improved sprinkler systems, better
exit signs, an additional stairway, and other features
to help people exit quickly during emergencies. The
International Code Council approved new safety regulations in the International Building Code and the
International Fire Code that include additional stairways, more space between stairways, stronger walls in
stairwells and elevator shafts, reinforced elevators for
emergency use, stricter standards for construction materials, better fireproofing, backup water sources for
the sprinkler system, glow-in-the-dark exit signs,
and radio amplifiers for emergency communications.
These safety changes were incorporated into the design
and construction of the Burj Khalifa in the United
Arab Emirates, which has a building height of
828 m and was completed in 2009. The skyscraper
construction incorporated multiple evacuation lifts,
super-high-speed elevators, thick concrete reinforcement in the stairways, and many other safety features.