12 July at 02:00PM
RISING VERTICALITY / DECLINING STABILITY
If you looked out of your window right now, you would definitely be able to spot at least one skyscraper or at least a ten storey building. These ten story buildings were the original skyscrapers, long before Burj Khalifa became a celebrity. I am sure over the next year, you will be able to spot two, if not more, if you looked out your window again. Is this urban densification really the need of the hour or do we need to take a few steps back?
The Great Fire
The Great Chicago Fire (1871) led to a revolution in the design and construction industry with the emergence of the first modern skyscraper 14 years after the fire—The Home Insurance Building, as a part of the “Great Rebuilding.” Conforming to the demand of building faint ornamental buildings (which would traditionally require a greater investment), the architects devised a steel cage to support the building’s structure equipped with fireproof materials complying with the new fire laws. Fast-forward to the present, “Skyscraper Cities” has become a boom, an ode to modernization, and a necessity in creating thriving business districts. The essential question that lies herein: What are we sacrificing to deliver this definition of progression?
Direct and indirect impacts on the community, economy, and the environment, also referred to as the “Triple Bottom”: people, planet, pocketbook are observed during a structure’s construction and operations. This poses an imminent need to study the energy implications, economic sustainability, social consequences, and the long-term legacy of these buildings in our urban grain.
Vertical Garden Cities
Traditionally, “tall buildings” were considered a major energy guzzler and therefore, not a poster child for sustainable design. However, a new generation of skyscrapers motivated by the growing need to preserve resources and reduce the carbon footprint associated with construction practices have substantially transformed the new skyline, with energy-efficient smart buildings that carry an intent to “give back” to the ecosystem. This combined with the increase in the number of people choosing an urban lifestyle over suburbia has led to densification of urban centres, which are often a part of planning policies by city’s governments these days. There are exemplary instances of how the impacts of vertical garden cities relating to densification have been positive. Improvements in the design of the tall buildings means that more compassion is gained in an urban context and there is a greater increase in the volumetric capacities of cities. A good example would be the inclusion of gardens within the built environment.
But what does the future hold? The impending growth, as we can already see materializing, are “hyper cities”—layered 3D cities connected at the horizontal and vertical levels, tied together to create a harmonious urban form that functions as one entity. These cities will accommodate urban sprawls, vertically, without compromising on the essence of community living.
The Lingering Design Flaw
There could never be one set of design and construction management or even one strategy for every skyscraper built, even in the same vicinity. This is due to the varying environments that these buildings are located in, which has a direct impact on the comfort levels and life cycle of the building for the future. The city of Toronto has observed glass facades rising more than ever in the last decade. These are fundamentally high energy wasters with heat loss (or gain) that are up to ten times greater in a glass plate building than in a section of typical masonry construction. It also brings about the need to combat thermal comfort of the occupants (even more so in the last five years, kudos global warming) with mechanical heating and ventilation systems that eventually cancel out the carbon footprint that could have been reduced through ethical and sustainable construction practices. A phenomenon that has been surfacing with scaled-up magnitudes throughout the urban sprawls—“sick building syndrome”—can be accredited to the need for constant use of air conditioning and heating. The syndrome originates due to a lack of oxygen combined with high levels of carbon dioxide and carbon monoxide. Ultimately it results in the occupants of the building experiencing flu-like symptoms.
The other notable downside of this massive vertical densification is a phenomenon that we all have experienced while walking through the streets of downtown Toronto—the downdraught effect. That sense of almost being blown away by the wind is a result of the wind hitting the buildings and pushing downward at a high velocity. It does not sound too dangerous or life-threatening until we read reports of parked vehicles being overturned or almost hitting pedestrians because of the blunt thrust that they experience because of these winds. The velocity of the air hitting the buildings only gets higher with the increasing height of the buildings, which results in enhanced ground winds.
Case of San Francisco, California (Land Subsidence)
San Francisco is a good example of a city that has experienced bustling urban densification in the last two decades. It exemplifies the phenomenon of “land subsidence”—a geological phenomenon resulting in cities sinking gradually due to the absolute weight of the built environment. The collective weight of all the buildings in the city has been roughly estimated to be 1.6 trillion kilograms, causing the land to sink as much as three inches as the city has grown. One of the broad reasons can be attributed to the city being built along coastlines (soft soils), with an imminent threat of the sea levels rising to almost a foot by the end of the century. The soil’s high compressive nature can result in a sink of 8 to 10 millimeters instantly post-construction. With a prediction of 70% of the world’s population inhabiting large urban areas by 2050, development becomes a greater factor of concern than any other.
The situation calls for cities to revise plans to shift development scenarios away from coastal areas or reclaimed lands, specifically.
To Be or Not To Be
Is there a solution? Having analyzed the various pros and cons of this developmental grandeur, a solution that arises is the need to thoroughly study the impact of skyscrapers on city life, communal spaces, pedestrian safety, and the geology of a region before creating a developmental matrix for new urbanization pockets. More importantly, cities need to re-examine the need to go vertical: Is it the need of the hour or just an attempt to create a skyline that is forging modernization? The crucial question that eventually persists is “to be or not to be” (not with an explicit context to Hamlet, of course).