The magnificent skyscrapers and towering high-rises that comprise the skylines of the World's largest cities no longer represent just architectural and engineering masterpieces. Today, high-rise buildings denote power, prestige, wealth, and success. Some even embody national pride. Countries, cities, and even businesses compete against their rivals to possess the tallest and most impressive of these buildings. More than just steel, concrete, and glass, high-rise buildings are fast becoming a staple in major cities and financial centres all over the world.
According to the Emporis website, a database on buildings & the real-estate industry, there are now more than 88,500 high-rise buildings located in more than 7,000 cities worldwide.i Prominent cities such as Hong Kong, New York, Singapore, and Sao Paulo boast having over 2,000 high-rise buildings in their limits alone.ii Other large metropolises such as Shanghai, Dubai, London, and Chicago continue to grow their skylines as well ? not far behind. High-rise buildings have undeniably become the status symbols and landmarks of today.
Sadly, as demonstrated by the terrorist attacks on New York City's World Trade Centre towers in 1993 and 2001, and the bombing of the HSBC building in Istanbul in 2003, skyscrapers have increasingly become more attractive targets for terrorists due to their landmark prominence. Various studies of the 9/11 terror attacks and past incidents of high-rise building fires have identified two significant safety issues that need to be addressed: First, in the event of a fire, explosion, aircraft collision, or earthquake, how will the structural integrity of the building be preserved long enough to allow the occupants adequate time to evacuate? And second, in the event that the building's primary means of egress are compromised or unusable, such as in the 9/11 terror attacks on the World Trade Centre (WTC) towers, how are the occupants to safely evacuate the building?
To date, the discussion surrounding these two critical safety issues has primarily focused on how best to augment and harden the structural aspects and redundancy of buildings ? specifically their elevator shafts, stairwells, and critical junctures. Some reports have even suggested installing new and more effective fire suppression systems that utilize foam rather than water. The problem is that no matter how structurally resilient a building is made, if a fire breaks out and renders the primary means of egress, stairways and elevators, unusable, the building just becomes a stronger tomb. The dilemma of how to evacuate a building in the event its primary means of egress are compromised or unusable remains the foremost safety issue for occupants working and living in high-rises, and even low-rises, today.
The aim of this whitepaper is to illustrate the safety risks that face occupants of high-rise buildings. Through an examination of the vulnerabilities of high-rise buildings, the inadequacies of their evacuation processes, and past case studies, the strategic need for evacuation devices that provide a secondary means of egress when the primary means, stairways and elevators, are compromised or unusable, is demonstrated. Such an examination can be used by individuals, to enhance their personal safety, companies, to improve business continuity and limit liability, and insurers, to reduce litigation costs and potential payouts.
The principal defining characteristic of a high-rise building is naturally its height. However, the specificity of the definition varies greatly depending on the source. For example, the Emporis website, which is directed towards academics, engineers, and researchers, strictly defines a high-rise building as:
"A building 35 meters or greater in height, which is divided at regular intervals into occupiable levels [...with] an edifice [...] based on solid ground, and fabricated along its full height through deliberate processes (as opposed to naturally-occurring formations)."iii