Tall building design and its relationship to our cities has been the subject of many debates in the architecture, planning, and engineering professions for decades.
In Europe, where most of the world’s historic cities and most of the world’s sustainable buildings are located, the prime concern is whether tall building construction should be limited to the outskirts of historic cities. In the US, where skyscrapers have been part of the American identity since the 1920s, there is a growing shift toward thinking of new ways to refurbish and redesign these iconic skyscrapers to serve the growing population and protect them from demolition.
Asia, meanwhile, is experiencing a boom in tall building construction, brought about by the region’s growing economic power and population. But this sudden surge has left many cities and their surrounding environment struggling to keep up the fast changes and in China’s case, questioning their profitability.
All these factors have contributed to the changing form and function of the skyscraper, driven by the three Es: Energy, Ecology, and the Environment. The specific design conditions that governed the 21st century skyscrapers have shifted and have been analyzed and observed by Architect Emily Merrill and Dr. Lee Gray, whose research in the paradigm shift in skyscraper typology was published in the Council for Tall Buildings and Urban Habitat (CTBUH) 2012 Asia Ascending Conference.
I was specifically interested how they analyzed three specific design conditions where the paradigm shift in skyscrapers can be observed: base design and vertical organization, form, and façades.
Base design and vertical organization
Base design refers to the conditions at the base of a tall building including conditions at the ground plane and subterranean levels. Vertical organization refers to the distribution of programmatic functions within the tall building. According to Merrill and Gray, the base designs of the early skyscrapers (1850-1916) were typically single level lobby spaces with occasional commercial spaces, while the vertical organization has been typically single use. The Modernist skyscrapers (1940-1970) had substantial changes when zoning laws mandated expansive public plazas although the vertical organization remained single use. In the Postmodern era (1970-1999), government incentives started to reward public space at the base in exchange for additional allowable heights, resulting in changes in base design, resulting in large atrium spaces.
The 21st century skyscrapers are now integrally connected to their urban context by integrating mass transportation. Hong Kong’s skyscrapers are a good example of this, where a multi-layered pedestrian network which spans from deep below grade to several stories above connect buildings and transport networks. In terms of vertical organization, redefining how a building functions and how people use a building contributed to the increase in 21st century skyscraper efficiency and sustainability.
Optimization and manipulation of form
The overall shapes in early skyscrapers were designed to provide adequate daylighting. Thus, footprint shapes go beyond the rectangle or square, including “E,” “H,” and “U” shapes and floor plates were identical at every level. Then, the implementation of zoning codes mandated skyscrapers between 1916 to 1940 to step back and provide street-level light. Modernist and Postmodern skyscrapers remained typically extruded.
In all early forms, technological innovations, economics, politics, and client ego have historically played a role in the development of the skyscraper form. Today, new conditions of form include variation in shape, tapers, and central atriums and voids. The physical shapes now play around round, rectilinear to tri-winged and triangular to multi-shaped, but always now tapered as an answer to wind conditions and it minimizes wind and structural loads, materials, and energy. The best example of this is the world’s tallest building at 826 meters, the BurjKhalifa, whose tapered form is designed to withstand the high-speed winds that can reach 160 kph at altitudes over 700 meters.
Smart, sustainable façades
The early skyscraper façades reflected the mechanical and structural technologies of the period. They were made using masonry load bearing walls. The development of air-conditioning and non-load bearing curtain walls occurred in Modernist skyscrapers and continued to dominate to the present day, although the purpose has changed from primarily aesthetic to performance-based. Complex layered skins that now make up many built and emerging 21st century skyscraper are integral to achieve better environmental performance. Orientation and elevation of façades differ to blend in with the surrounding environmental conditions, and its systems are now designed with the intention of balancing solar gain, heat loss, daylight distribution, glare control, and so on to provide greater energy efficiency and comfort for the user.
The almost complete Shanghai Tower exemplifies this system, with two curtain walls with large atria spaces in between, allowing minimal need for additional cooling and heating. The Shanghai Tower is slated to be the largest and tallest double-façade system in the world. Similarly, Palafox Associates developed a façade system in one of its skyscraper projects, the proposed landmark building for a bank, with its twisting façade, gyrating glass curtain walls, double skin structure, and sloping walls to maximize natural lighting during the day.
The Council of Tall Buildings and Urban Habitat’s (CTBUH) Skyscraper Center, which keeps tabs on the world’s tall building construction, reports that there are currently 79 supertall (300-plus-meters) buildings in the world, followed by 846 tall (200-plus-meters) buildings. The BurjKhlaifa falls under the CTBUH category of megatall (600-plus meters).
In the Philippines, the tallest building crown has now been passed to the Gramercy Residences. Tall building design in the Philippines is only beginning to take shape starting with Rizal Tower, Luna Gardens, Hidalgo Place, Amorsolo East and West at Rockwell Center in a vertical urbanism. The west block of Rockwell Center has five facades–front, two-sides, the back at the fifth façade– beautiful view from the top looking down at the gardens, trees, swimming pool below, with panoramic views from the top overlooking Rockwell Center.
As a registered APEC Architect, Country Representative and Fellow for the CTBUH headquartered in Chicago, I can see that there is much we can learn from analyzing and further studying new trends in tall building construction and typologies. Sustained professional development is one of the requirements of the Mutual Recognition Agreement (MRA) for eligibility as an Asean Architect. Our biggest challenge as architects, planners, and designers, is how to sustain our own creative and technical development. We must learn what we can by joining international organizations and if opportunity permits, continue studying to develop a competitive edge.