Engineering Supertall Skyscrapers: Challenges and Solutions
- World Scholars Review
- 2 days ago
- 26 min read
Authors: Soren Comer and Simran Katari
Mentor: Markus Baumgartner. Markus is a doctoral candidate in engineering at the University of Oxford.
Abstract
The ability to construct supertall skyscrapers has revolutionized urbanization. Creating “mile-high” buildings poses extreme engineering challenges and requires substantial technological advancements. This review paper investigates the challenges and recent solutions developed for creating tall structures safely, usefully, and efficiently. We conducted this research by examining the major core challenges and then analyzing modern solutions in detail. Specifically, elements such as advanced materials, structural designs, and wind engineering techniques have been crucial to furthering the understanding of the development and creation of major skyscrapers. Through these advancements, engineers are able to conceive a new generation of structures, while changing the mainstream perception of common cities. The future of building tall has endless possibilities, with creators already starting to brainstorm new and mind-blowing projects. Soon-to-be supertall skyscrapers, such as the Jeddah Tower (formerly Kingdom Tower) in Jeddah and Next Tokyo in Tokyo, utilize the many aspects mentioned in this review paper, further proving how humans can adapt and modernize civil engineering in a beneficial way for the world.
Introduction
With the rapid urbanization of cities, the need for skyscrapers has increased, particularly the need for supertall buildings. According to the Council on Tall Buildings and Urban Habitat, a building becomes ‘supertall’ if it is over 300 meters tall, and “megatall” if it is taller than 600 meters (Choi et al., 2017). The first supertall building, the Chrysler Building (319 meters), was constructed in New York in 1930 (Stravitz & Gray, 2002), a significant surge in the number of supertall skyscrapers has occurred since 2010. Many cities desire advanced and tall buildings, as they serve as aesthetic architectural landmarks and efficiently utilize ground space in busy urban areas (Konar, 2025). In further detail, many citizens or even tourists from around the world love to see and appreciate the scale and design of these supertall skyscrapers. Additionally, building taller saves on space because rooms aren’t being constructed horizontally on more land, but rather vertically on the same plot. This allows for the same (or even more) space to be used efficiently, while not occupying all the land needed for comfortable urban life, such as roads and parks.
To build taller skyscrapers, engineers need innovative technology and new solutions to core problems. Because of this, engineers are constantly developing new solutions and designs that can make buildings safer and taller. Skyscraper design is multidisciplinary and leverages innovations in simulations and materials engineering to better current solutions.
In order for a skyscraper to be built, it must meet the requirements of being useful, safe, sustainable, and not overly expensive. For a building to be useful, it must have sufficient space for people and be comfortable. To be seen as safe, it must be designed and verified to withstand forces beyond what it is ever expected to encounter. For it to be sustainable, it must be both energy-efficient and long-lasting. For skyscrapers to be affordable enough to build, they must utilize comparatively inexpensive materials such as concrete or steel.
In this review paper, we will discuss various design challenges associated with building a skyscraper, including reducing building sway, supporting increasing vertical loads, and striving for affordability, safety, and utility. We will also discuss innovative and common solutions to some of these problems, along with building techniques and a section on advanced materials. In addition to discussing core challenges and design solutions, we will also explore the future of skyscrapers, as technology and building techniques continue to evolve. For the sake of completeness, we mention and list all the problems associated with skyscrapers; however, an exhaustive description is beyond the scope of this discussion for other topics such as building foundations, temperature fluctuations, and internal systems.
Challenges in Modern Supertall Buildings
When constructing modern supertall skyscrapers, many new challenges arise that wouldn’t usually occur in normal-sized buildings. As the height of the building increases, factors such as faster wind speeds, heavy materials, temperature changes, and vertical loads must be taken into consideration when selecting materials, integrating internal systems, and constructing the skyscraper to ensure stability, safety, and sustainability.
One core design challenge, as aforementioned, is the increase in wind intensity. As elevation increases, wind becomes stronger, resulting in a greater force pushing against the tall buildings. Specific to skyscrapers, the power-law equation demonstrates that as altitude increases, wind speed increases due to the diminishing impact of shear forces as the wind interacts with the ground. This results in higher oncoming wind pressure on the face of a building. Atmospheric friction is manifested through shear forces, which cause the air to cling to nearby surfaces as it flows. This effect is typically known as a boundary layer effect and is responsible for wind speed increasing as you move further away from the ground. This, in turn, imposes a higher wind pressure on buildings. The atmospheric boundary layer is approximately 1 kilometer (~3300 feet) deep, making it a significantly larger problem for supertall buildings compared to regular skyscrapers (Brune, 2023). The power law is the following:
With the following variables: V(z) = Wind speed at height z (m/s), Vref = Reference wind speed at zref, which is the reference height (meters), and α = Terrain roughness exponent (0.10–0.40 based on the environment) (Simiu & Scanlan, 1996).
However, aside from the pressure, vortex shedding also plays a significant role. Vortex shedding is the phenomenon that occurs when a fluid (in this case, wind) flows past a structure, creating swirled motions of force in alternating low-pressure zones. The equation for the frequency of Vortex Shedding is determined by the Strouhal number, with the equation being:
With the following variables: fs = Shedding frequency (Hz), St = Strouhal number (dimensionless, typically around 0.2 for bluff bodies), V = Wind velocity (m/s), d = Characteristic dimension perpendicular to wind direction (meters) (Simiu & Scanlan, 1996).
One common misconception is that wind pressure, by itself, stresses the material in buildings, which is critical, but it is only a static process. Vortex shedding, on the other hand, differs in that it causes oscillations and vibrations. Additionally, vortex shedding can become intense in the presence of lean skyscrapers and strong winds, generating sway and vibration (Simiu & Scanlan, 1996). Consider the tip deflection of a cantilever beam, for example. When applying force, the beam sways and bends a notable amount, as it is slender and thus deforms disproportionately to its strength, altering its original position. A cantilever beam is a good approximation for a tall building. The sway motion poses a challenge for both the engineers and the people who will be in the building, as it isn’t safe. A final aspect of wind is the occupant’s comfort. As wind velocity increases, it causes more vortex shedding and therefore an immense amount of sway. This is when the building sways, from side to side, as the wind pushes it around. Creating and researching tools to adjust this sway is crucial because it is hazardous, let alone uncomfortable, for occupants to be in a building that isn’t very stable and grounded (Fu, 2018).
Another key factor to consider when building supertall skyscrapers are the materials used. Specifically, these properties must be taken into consideration: compressive strength, tensile strength, stiffness, also known as Modulus of Elasticity or MOE, ductility, inherent damping, weight, and long-term behaviors. Compressive and tensile strength describe the material’s ability to be crushed and stretched, respectively. Stiffness governs deflection, and although it is different from strength, it is still referenced alongside it. Ductility allows the material to conform in different ways and absorb the energy needed for deformations, which is especially beneficial when dealing with seismic activities. Inherent damping is critical because it absorbs the effects of wind and other seismic activities, thereby increasing occupant comfort and mitigating sway. Natural structural damping in taller buildings isn't as high, data shows it is usually 0.3-0.5% in tall buildings as opposed to the 3-8% found in shorter buildings (Smith & Willford, 2008). Weight is especially crucial, since a tall building must not be too heavy. Lastly, the long-term behaviors include creep and shrinkage. Creep is defined by the constant reduction of the material’s length due to continual compression. This usually happens when concrete is subjected to immense pressure for prolonged periods of time. An example of this is the Burj Khalifa, which is expected to shorten by approximately 300 millimetres over the next 50 years (Baker et al., 2007). Secondly, shrinkage is similar, but emerges from different causes. It occurs when the size of a concrete member decreases due to a change in the hydration of the concrete (Wu et al., 2017). Since the concrete is wet during construction, the water in the concrete occupies some space. As it dries, the water evaporates, causing the concrete to shrink. Although material choice is often overlooked when considering the creation of a supertall skyscraper, it is an essential aspect that can singlehandedly determine the structure’s integrity and limits.
As we continue to build up and rapidly increase the height of our buildings, the amount of vertical loading increases, primarily due to the force of gravity. The greater the gravity loading buildings elements must bear, the more challenging it is to maintain safe and sturdy vertical transportation. Optimizing energy consumption is a crucial component of vertical transportation, as elevators account for 2-10% of a building’s energy usage on average (Al-Kodmany, 2015). Additionally, the building must be able to support its weight, which becomes increasingly difficulty with height,
Aside from focusing on the outer elements of super skyscraper buildings, many internal components are also necessary. Water plumbing systems are essential in all buildings, but achieving a consistent flow in a skyscraper is particularly challenging. Tall buildings solve this issue by integrating staged domestic water systems to pressurise or depressurise fluids in pipes. Through the use of booster pumps and pressure-reducing valves, gravity no longer becomes a limiting factor, and skyscrapers can address issues such as height, redundancy, water quality, and variability in demand, at the cost of vast energy consumption. In many skyscrapers, an immense number of pumps are needed to transport water to higher elevations; in many cases, skyscrapers have mechanical floors that contain equipment solely for tanks and pumps foregoing any residential or office space (American Society of Plumbing Engineers, 2015).
Moreover, large buildings, require a stable base. To remain stable in earthquakes, storms, and even shifting grounds, there is a need for a strong foundation to build upon. More specifically, a main component to pay attention to is soil. A good understanding of soil behavior, also known as soil mechanics, is vital to the construction of tall buildings as it enables engineers to design structures with the appropriate bearing capacity, settlement control and soil-structure interaction mechanisms required. Using soil mechanics, engineers can build the proper foundation to withstand the considerable weight and balance of the building (Parker & Wood, 2013).
Commonly overlooked but extremely relevant is the change in season, and therefore, the change in temperature. As temperature changes, the materials in a skyscraper react and have a significant effect on the building as a whole. As a material heats up, it expands, and as it cools, it contracts. This induces immense forces within the structural components of a building, which may break or weaken over time. The forces arise as different parts of the building need to account for expansion and shrinkage, especially if the building temperature does not change uniformly. The reason this is a significant issue when building skyscrapers is that more material is affected, and the taller and bigger the skyscraper becomes, the stresses induced in materials from thermal changes change disproportionately as the building height increases. When things expand and shrink, it disrupts the building's proportions and can cause severe damage and danger to the people inside (Advanced Architectural Products, 2023).
Last but not least, safety and sustainability are crucial considerations when undertaking a large and influential project like a skyscraper. Although it has been mentioned throughout the other subtopics of modern skyscraper challenges, one of the primary tasks when building skyscrapers is ensuring that the building is safe enough to use or live in. For starters, when a fire occurs, evacuation must happen quickly and efficiently, which becomes more difficult the higher up you are (National Fire Protection Association, 2024). Additionally, the rapid increase in urbanization and the construction of newer skyscrapers also lead to an immense amount of greenhouse gases and carbon emissions, exacerbating global warming (Pomponi et al., 2021). As this becomes a more prominent challenge in the 21st century, engineers must brainstorm new ways to advance technology and supertall skyscrapers while ensuring they are safe and do not harm the environment.
Advanced Structural Systems
A structural system is the primary load-bearing frame or skeleton that makes a skyscraper safe and stable. One of the most common components in a structural system is the core, which is a strong vertical structure inside a skyscraper that supports a significant portion of the vertical weight (Parker & Wood, 2013). For a structural system to be effective, it must be strong enough to support its own weight, stiff enough to resist excessive sway, lightweight, and provide sufficient floor space for occupants. The structural systems we will discuss are the tube system, buttressed core system, core-outrigger system, the diagrid system, and conjoined towers.
The main idea of a tube system is that it makes a skyscraper like a giant hollow block, where the main load-bearing system is the exterior structure made of columns placed closely together and connected by steel beams (American Institute of Steel Construction, 2017). Overall, the tube system more efficiently utilizes materials and creates a stronger building than previously used rigid steel frames, resulting in a more open floor plan with increased space. The downsides to a tube system are that, because the outer columns are so close together, there is limited space for windows and a limited variety in the designs that can incorporate the tube structure. Besides the generic tube system, there are also several variations of the tube system, including the framed tube system, trussed tube system, and bundled tube system. An example of a building that uses a braced tube system is the John Hancock Center in Chicago, built in 1969 (Iyengar, 2000).
An increasingly popular advanced structural system is the buttressed core system. A buttressed core system is a building with a strong central core, often made from reinforced concrete, featuring three shear walls or wings, typically in a Y-shape that extends from the core (Barr, 2019). Currently, the most famous example of a buttressed core system is the Burj Khalifa, completed in 2010 (Baker & Pawlikowski, 2012). This system is so strong because the core helps to support its weight and provide torsional resistance whilst each buttress wing is supported by the other two wings and the core, providing a vast base and high moment of inertia relative to the building material used, helping to distribute bending forces from wind throughout the whole building and providing shear resistance (Baker & Pawlikowski, 2012). Because of this and the fact that its common y-shape is more aerodynamic than other buildings, the buttressed core system is advantageous for making skyscrapers, even though it does have some limitations. For example, its shape and floor layout make it unsuitable for an office building that would require a more open floor layout, as its core occupies a significant portion of its space. Another limitation of the buttressed core system is its increased complexity in construction, leading to problems such as the need for numerous reinforcements, including rebars, and anchoring issues due to variations in wall thicknesses and curvatures (Peirce, 2023).
A core-outrigger system is a structural system that utilizes a central concrete core connected to perimeter columns by outrigger trusses. An example of a core-outrigger system is the Aqua Tower in Chicago, which utilizes a core-outrigger system to connect the central core to the columns' perimeter using cantilevered balconies, in order to mitigate lateral drift (Chicago Architecture Center, n.d.). Connecting the central core to the outer columns helped increase the building's stiffness, which reduces sway and enhances stability. Another reason a core-outrigger system is so effective is that when the building is exposed to a force like wind, the energy is transferred from the core to the entire width of the building, allowing the whole structure to work together, similar to the buttressed core system (Chicago Architecture Center, n.d.). Lastly, this system also frees up space inside the building, making it easier and more efficient to use. Some limitations of the core-outrigger system are that it is structurally complex and can be challenging to coordinate tasks such as running outriggers across mechanical floors. Additionally, outriggers placed at only a few locations on the building can generate significant forces to counter the core overturning moments (Choi & Joseph, 2012). Another limitation is that this structural system is very space-consuming, limiting the amount of usable floor and window space in large buildings.
An increasingly popular skyscraper structural system is the conjoined tower. In the future, conjoined towers could be used to create skyscrapers taller than ever before, potentially reaching heights of over 200 stories (Moon, 2019). By conjoining two buildings, the lateral stiffness of both buildings is increased, allowing the building to be made even taller. An example of conjoined towers is the Petronas Twin Towers in Kuala Lumpur, made in 1998 (Parker & Wood, 2013). According to the Council on Tall Buildings and Urban Habitat (CTBUH), when outrigger trusses are extended from the cores of the two buildings in the direction of the skybridge and connected to exterior columns, then up to 40% of the overturning moment can be resisted. (Choi & Joseph, 2012). But there are reasons we aren’t making more conjoined skyscrapers right now, other than the normal problems a skyscraper has. Conjoint skyscrapers would require a lot more planning and would occupy a significantly larger space, making them less common, despite having the potential to provide the stability to make skyscrapers substantially taller.
Lastly, a diagrid system is an advanced structural system where a building's exterior is composed of diagonal members arranged to form triangular latticework. The diagrid system is used in many stunning buildings, such as the Guangzhou International Finance Center. This system is very effective at resisting both the building's own weight and sideways forces, such as wind, because the diagonals can handle multiple types of forces. The diagonals can handle lateral loads more effectively due to axial action (transferring the force through the diagonals), as opposed to the bending of a vertical column (Moon, Connor & Fernandez, 2007; Jani & Patel, 2013). Additionally, because the diagonal members can handle multiple types of forces, a diagrid system makes more efficient use of resources, decreasing reliance on other systems that would typically counteract the forces of lateral resistance. and does not require a core (Jani & Patel, 2013). The last advantage of a diagrid system is that it often boasts a stunning visual appearance, making it look unique and iconic, and it can feature a great deal of architectural variety in its design. Like all structural systems, the diagrid system does have some limitations. First, because a diagrid system relies on the diagonal members for both vertical and horizontal resistance, in the case of an earthquake, if the members were damaged, the building could risk losing both vertical and horizontal support simultaneously. Another limitation is that diagrid columns can create significant tension forces between the diagrids and the floor slabs, requiring designers to use special tension ties (Parker & Wood, 2013). This system has primarily been made possible by new advancements in mathematical modeling and simulations, allowing engineers to simulate structures like the diagrid system that they could not previously, demonstrating how these technological advancements make more things possible.
Advanced Wind Engineering Techniques
Wind is one of the biggest challenges when it comes to building a skyscraper because of the immense forces wind places on the building. When wind hits a building, it causes it to sway or bend with the wind (Irwin, Denoon & Scott, 2013). The wind also causes buildings to vibrate back and forth because of vortex shedding. Too much sway or vibration can make people inside a building uncomfortable, so engineers must use different methods to minimize the building's movement. With advancements in recent technology, engineers can utilize better models, such as wind tunnel testing and computational fluid dynamics, to more accurately predict phenomena like the maximum wind speed in a specific area.
The primary methods engineers employ to mitigate sway and vibration include modifying the shape or design of a building to reduce the aerodynamic profile and vortex shedding, installing dampers to counteract sway, or utilizing more resilient materials. One shape engineers use is a spiral or a twisted shape. By designing a building in a spiraling shape, engineers ensure that instead of the wind hitting one side of the building, it wraps around the structure (Irwin, Denoon & Scott, 2013; Nnamani, 2012). The spiral shape also helps reduce vortex shedding because, for vortex shedding to occur, an alternating low-pressure zone is required, and a spiral shape helps disrupt this pattern. The first twisted skyscraper was the Turning Torso in Malmö, Sweden, which was completed in 2005, making this technique relatively new (Guinness World Records, 2005). Another structure type engineers might use is a stacked tube system or a bundled tube system. An example of one type of bundled tube system is a building made up of interconnected tubes or columns surrounding a central core (Ali & Moon, 2007). This system creates a strong structure that can distribute any of the building's loads, including wind, and reduce sway. The most famous example of a building made from a bundled tube system is the Willis Tower in Chicago. In addition to altering the entire shape of the building, some engineers incorporate blow-through floors or holes in their structures to allow wind to pass through. By enabling the wind to pass through instead of hitting the building, these holes reduce the amount of wind that hits the building and provides it with a path to dissipate, thereby reducing wind loads and sway (Irwin, Denoon & Scott, 2013; Nnamani, 2012).
When building a skyscraper, the material from which it is made matters a great deal. When considering the effects of wind, it is essential to understand which materials should be used for different parts of a skyscraper. Steel and concrete are two of the most commonly used materials in building skyscrapers due to their strength and accessibility. Concrete is often used as the core of a building due to its high compressive strength and stiffness. Steel is often used for structural frames, bracing systems, or beams and columns due to its high strength, ductility, and ability to bend, which helps resist wind. Because of this, engineers have to use a combination of these two materials to combat the wind. One of the most important factors to consider in a material when evaluating its wind resistance is its inherent damping. Inherent damping is a material's ability to dissipate energy or vibrations (such as wind or vortex shedding) without permanently deforming. Between steel and concrete, concrete has better inherent damping (Lago, Faridani & Trabucco, 2018), meaning it is more effective at resisting vibrations and unwanted movements, unlike steel, which can bend more easily. Due to this, concrete plays a crucial role in the construction and design of a skyscraper.
Engineers often put dampers in skyscrapers as another way to keep buildings from swaying or moving. One common dampener is the sloshing damper, which has been installed in buildings over the last 25 years. A sloshing damper uses water to counter the sway of a building. When the building moves, the water moves in the opposite direction and pulls the building back (Larsen, Berahman & Aswegan, 2024). Amongst other skyscrapers, the Highcliff Residential Tower in Hong Kong, built in 2003, is one of the most notable buildings to feature a sloshing damper. Another type of dampener is the tuned mass damper. A tuned mass damper consists of a spring, damper, and mass, and is attached to a building. The damper is then tuned to the building's natural frequency, so that it will vibrate out of phase with the structure, causing it to absorb some of the energy and reduce sway (Purdue University, 2002). A good example of a tuned mass damper is the Taipei 101 skyscraper in Taiwan, completed in 2004 (Poon et al., 2004).
Before engineers can build or test their building, they first have to know what wind climate the building will be in. A wind climate encompasses wind speed, direction, and recurrence intervals, which can be determined through long-term wind data. Engineers need to know the wind climate so they can determine if the wind is coming from all sides of a building or just one, and thus, the maximum wind speed they will have to test for. A good example of the effects of wind climate can be seen at Chicago's airport. The Chicago airport has eight different runways because the wind there can come from multiple directions (Mitchell, 2025). Once engineers understand the wind climate, they can test the building's resistance to wind. To test a building's resistance to wind, engineers use one of three test types: high-frequency balance (HFB), high-frequency pressure integration (HFPI), and aeroelastic techniques. Despite the standard varying in the industry, engineers frequently combine these tests to get the best data (Nnamani, 2012).
HFPI testing is conducted by using a model of the building in a wind tunnel (Denoon, 2018), where pressure fluctuations are measured at different points on the building simultaneously to calculate the overall wind loads. Engineers also utilize computational fluid dynamics, a numerical method for simulating wind loads (Irwin, Denoon & Scott, 2013). Computational fluid dynamics (CFD) uses mathematical models and computer software to simulate the wind flow around a building. CFD can provide a detailed representation of multiple forces acting on a building simultaneously, making it easier for engineers to visualize how their building would react to wind. Engineers also utilize a technique known as FEA, or Finite Element Analysis. FEA utilizes FEM, a mathematical system, to simulate how a building would react to various forces, in this case, wind. FEA works by dividing an object into smaller elements through meshing, then applying relevant physics and equations to each element, assembling the equations, and finally solving them (Zienkiewicz, Taylor & Zhu, 2005).
Advanced Materials
Developing advanced materials is crucial for constructing supertall skyscrapers, as they are necessary to ensure financial viability and safety guarantees. The advanced materials must possess high strength while minimizing cost, material usage, and weight. If the correct materials aren’t used, it could pose a significant safety hazard and be a contributing factor to a skyscraper's failure. This is why the importance of advanced materials is paramount, and why many engineers are constantly seeking better and more innovative options. As opposed to just “picking” new materials, though, engineers seek to develop techniques and technological advancements to adjust the materials they already have, making them better than before.
One extremely effective option is high-strength concrete. Known as the backbone of supertall skyscrapers, this type of concrete is made with increased compressive strength, overcoming the issues of smaller ductility and tensile capacities. Compared to steel systems, which are mentioned below, concrete lateral systems have higher inherent damping. Regular concrete is made from cement, combined with a mixture of fine and coarse aggregates, including sand and gravel. This differs from high-strength concrete, which uses less water, primarily smaller materials, silica fume, superplasticizers, and various fibers. The recent innovation of adding superplasticizers makes the concrete more fluid, as it contains less water, making it easier to work with and pour at higher altitudes. Similarly, steel fibers, in particular, increase tensile strength, ductility, and toughness, which helps the concrete better handle pulling forces and resist cracking. (Amran et al., 2022).
Additionally, it may also include Supplementary Cementitious Materials (SCMs), such as ground granulated blast-furnace slag, fly ash, and metakaolin. This perfect mix of materials allows for the concrete to be tightly packed and sturdy (Amran et al., 2022). For example, the One World Trade Center, a 541-meter-tall skyscraper in New York City, uses ultra-high-strength concrete. Ahmad Rahimian, Director of Building Structures at WSP, confirms that this allowed the walls to be thinner, maximizing area usage and minimizing the weight of materials (Whitehead, 2017), which are two properties that overall affect the possible height of a skyscraper, allowing it to increase substantially.
On the other hand, high-strength steel is another excellent option for selecting an advanced material when building a skyscraper. This lightweight material has been adapted to have increased strength and yield strength. In contrast to concrete, using steel allows for the behavior of the structures to be more predictable and is more dimensionally stable, with less creep and shrinkage. The use of steel in composite floor panels is also beneficial because it is lighter, thereby reducing the overall weight of the structure. Some processes are also used to enhance the properties of steel. For example, thermomechanical control processes that use heat, or the newer system of Vacuum Arc Remelting.
Additionally, it is also very sustainable: architectural steel often has a recycled material content, averaging as high as 93% (American Institute of Steel Construction, 2017). Going back to the example of the One World Trade Center, Whitehead also states that over 95% of the structural steel was recycled, further exemplifying the sustainability of this new steel (Whitehead, 2017).
Furthermore, another impactful example is the Merdeka Tower in Malaysia. At 678.9 meters high, this skyscraper utilizes high-strength steel, which saves on 20% of the buildings weight (ArcelorMittal, n.d.). This weight reduction has helped engineers immensely by allowing them to build higher without worrying about the skyscraper's heavy weight.
The Future of Supertall Skyscrapers
Although skyscrapers could become much taller if they were limited only by their own weight, or dead loads, live loads, such as wind, impose practical limitations on a skyscraper. For example, a skyscraper made of just concrete has a theoretical limit of around 8,500ft (if it has 12,000 psi (80MPa) crushing strength), and a skyscraper of just steel has a theoretical height limit of around 14,700ft (Parker & Wood, 2013). However, the tallest building in the world right now, the Burj Khalifa, is only 2,717 feet tall due to factors such as wind, seismic activity, and live loads within the building, as well as the prohibitive cost of using better building materials. Another reason we can’t make buildings taller is that it would not be practical for factors like water pressure and travel time. If we account for all these factors that make it difficult to build tall buildings, the practical limits for different structures decrease significantly, as Fazlur Khan demonstrates. Fazlur Khan estimates that a building with a rigid frame, steel columns connected by rigid nodes, has a practical limit of 30 floors (Ali & Moon, 2007). He estimates that a building with truss/braced tubes, diagonalised steel braced trusses on the outside of the building, has a practical limit of 100 floors. Lastly, he estimates that a building that uses bundled tubes, interconnected tubes, or columns around a central core has a practical limitation of 110 floors. According to Moon and Ali’s analysis (Ali & Moon, 2007), a building with a concrete core-outrigger and mega column system, featuring a central core made of reinforced concrete connected to mega columns on the outside of the building by outriggers, has a practical limit of 140 stories. Also, according to Moon and Ali’s analysis, a skyscraper with a modern tube system has a practical limit of 140-180 stories.
It is currently the year 2025, and the first skyscrapers were built over a century ago – it’s about time that engineers test the limits of futuristic, megatall buildings. A few examples of this breakthrough are evident in the Kingdom Tower in Jeddah, Saudi Arabia, and the proposed Next Tokyo project in Tokyo, Japan.
The major project of the Kingdom Tower in Jeddah started in 2009, and had the goal to be the tallest, most advanced building in the world. Specifically, the goal of this tower was to identify the faults in the Burj Khalifa, adapt to them, and create a better tower. However, like all major construction projects, this tower encountered some challenges. Firstly, the engineers aimed to build the world's tallest tower, but they also wanted to minimize space requirements (Weismantle & Stochetti, 2015). Knowing that they needed the height factor while also needing a stable base was a challenge, but engineers decided on a final design of a tapered buttressed “Y” shape for the tower. This new and innovative tapered buttressed core offers several benefits, including maximizing sunlight exposure, providing lateral support, and particularly resisting bending moments incurred by wind. At a planned height of about 1,000 meters (3280 feet or roughly 328 flights), transportation up and down is more than a hassle. The Kingdom Tower uses KONE's UltraRope (KONE Corporation, n.d.) to provide vertical transportation feasibility. This revolutionary rope claims to enable elevators to travel up to 1,000 vertical meters, surpassing anything previously achieved, and ensures transportation is both safe and efficient. As stated in Weismantle & Stochetti’s (2015) case study, an open mind and the ability to be flexible and adaptive are necessary for a large project like this one, due to the numerous challenges faced and pivots that need to be made. Building the next tallest skyscraper isn’t easy, but it will be a technological and societal breakthrough that will benefit global urbanization overall (Weismantle & Stochetti, 2015).
Similarly, the proposed Next Tokyo tower is striving to break limits like never before. The Next Tokyo tower has a primary purpose of elevation: to protect the Japanese from rising sea levels in a low-lying area by constructing a city-like structure above the land. Next, Tokyo will also serve as a mid-bay transit hub, as it will be conveniently located in the central area of many tunnels and forms of transportation. A major similarity between Next Tokyo and the Kingdom Tower is that they are both designed with a tapered shape. Although not a buttressed “Y” shape, Next Tokyo resembles an aerodynamic shape that can withstand intense winds and has slots where wind can flow through smoothly. The design also incorporates an articulated façade around the tower’s legs, as an extension of their overall plan to use cloud harvesting as a water source, rather than dealing with the challenges of transporting water to such high altitudes. This skyscraper is designed to accommodate 55,000 residents within its projected height of a mile (1,600 meters) (Malott et al., 2015).
Conclusion
Skyscrapers are crucial to the advancement of cities, as we face an increase in population and urbanization. A skyscraper is classified as a building over 300 meters tall, but as our technology and techniques advance, we continue to build ever taller structures. As we continue to build taller buildings, we are faced with increasingly difficult problems, such as increased wind and vertical loads. To overcome these problems, engineers employ various methods to ensure the safety of skyscrapers. To make their buildings stronger, engineers use advanced structural systems, such as the tube system, buttress core system, core outrigger system, and diagrid system. These systems are innovative ways to increase the height and stability of tall buildings, and are used in conjunction with advanced materials such as high-strength concrete, high-strength steel, and carbon fiber. Because wind is one of the biggest obstacles when building a skyscraper, engineers have developed numerous ways to mitigate its effects. Engineers often modify the physical shape of their buildings to resemble a twisted or tapered form, or utilize blow-through floors to reduce the actual amount of wind that hits the building. They also utilize dampers, such as sloshing dampers and tuned mass dampers, to counteract the effects of sway. Lastly, to test their skyscrapers, engineers utilize improved wind tunnel testing technologies and mathematical simulations, such as FEA (Finite Element Analysis). As this technology continues to advance and our structural systems and materials improve, skyscrapers in the future may become significantly taller. Already, the proposed Next Tokyo is planned to be 1,600 meters tall.
References
Advanced Architectural Products (2023) The Effect of Thermal Expansion with Common Building Materials. Available at: https://greengirt.com/articles/the-effects-of-thermal-expansion-with-common-building-materials/ [Accessed: July 2025]
Al-Kodmany, K. (2015) “Tall Buildings and Elevators: A Review of Recent Technological Advances.” Buildings, 5(3), pp. 1070–1104. https://doi.org/10.3390/buildings5031070
Ali, M.M. & Moon, K.S. (2007) “Structural Developments in Tall Buildings: Current Trends and Future Prospects.” Architectural Science Review, 50(3), pp. 205–223. https://doi.org/10.3763/asre.2007.5027
American Institute of Steel Construction (2017) More than Recycled Content: The Sustainable Characteristics of Structural Steel. Available at: https://www.aisc.org/globalassets/aisc/publications/white-papers/more-than-recycled-content.pdf [Accessed: July 2025]
American Society of Plumbing Engineers (2015) Plumbing Engineering Design Handbook, Volume 2: Plumbing Systems. Westlake Village, CA: ASPE.
Amran, M. Huang, S., Onaizi, A.M., Makul, N., Abdelgader, H.S., & Ozbakkaloglu, T. (2022) “Recent Trends in Ultra-High Performance Concrete (UHPC): Current Status, Challenges, and Future Prospects.” Construction and Building Materials, 352. https://doi.org/10.1016/j.conbuildmat.2022.129029
ArcelorMittal (n.d.) Merdeka 118: Reaching for the Sky in Malaysia. Available at: https://constructalia.arcelormittal.com/en/case_study_gallery/malaysia/merdeka-118 [Accessed: July 2025]
Baker, W.F. & Pawlikowski, J.J. (2012) “Higher and Higher: The Evolution of the Buttressed Core.” Civil Engineering Magazine, 82(9). https://doi.org/10.1061/ciegag.0000420
Baker, W.F., Korista, D.S., Novak, L.C., Pawlikowski, J., & Young, B. (2007) “Creep and Shrinkage and the Design of Supertall Buildings—A Case Study: The Burj Dubai Tower.” ACI Special Publication, SP-246, pp. 133–148. https://doi.org/10.14359/18983
Barr, J.M. (2019) The Technology of Tall (Part I): Skeletons, Outriggers, and Buttresses. Building the Skyline. Available at: https://buildingtheskyline.org/skyscraper-technology-1/ [Accessed: July 2025]
Brune, W. (2023) 11.1 The Atmospheric Boundary Layer Is Your Home. John A. Dutton Institute, Pennsylvania State University. Available at: https://www.e-education.psu.edu/meteo300/node/711 [Accessed: July 2025]
Chicago Architecture Center (n.d.) Core and Outrigger Construction. Available at: https://www.architecture.org/online-resources/architecture-encyclopedia/core-and-outrigger-construction [Accessed: July 2025]
Choi, H.S., Ho, G., Joseph, L. & Mathias, A. (2017) Outrigger Design for High-Rise Buildings. London: Routledge. https://doi.org/10.1201/9781315661971
Choi, H.S. & Joseph, L. (2012) “Outrigger System Design Considerations.” International Journal of High-Rise Buildings, 1(3), pp. 237–246.
Denoon, R. (2018) “Wind Tunnel Testing for Tall Buildings.” STRUCTURE Magazine, (June). Available at: https://www.structuremag.org/article/wind-tunnel-testing-for-tall-buildings/
Fu, F. (2018) Design and Analysis of Tall and Complex Structures. Kidlington, UK: Butterworth-Heinemann. https://doi.org/10.1016/C2015-0-06071-3
Guinness World Records (2005) First Twisted Skyscraper. Available at: https://www.guinnessworldrecords.com/world-records/109082-first-twisted-skyscraper [Accessed: July 2025]
Irwin, P., Denoon, R. & Scott, D. (2013) Wind Tunnel Testing of High-Rise Buildings. Abingdon: Routledge. https://doi.org/10.4324/9781315879529
Iyengar, H. (2000) “Reflections on the Hancock Concept.” CTBUH Journal. Available at: https://global.ctbuh.org/resources/papers/download/1231-reflections-on-the-hancock-concept.pdf
Jani, K. & Patel, P.V. (2013) “Analysis and Design of Diagrid Structural System for High-Rise Steel Buildings.” Procedia Engineering, 51, pp. 92–100. https://doi.org/10.1016/j.proeng.2013.01.015
Konar, T. (2025) “Historical Background, Current Trends and Future Prospects of Supertall Buildings.” Discover Civil Engineering, 2(14). https://doi.org/10.1007/s44290-025-00172-5
KONE Corporation (n.d.) Rising into the Future. Available at: https://www.kone.com/en/news-and-insights/stories/rising-into-the-future.aspx [Accessed: July 2025]
Lago, A., Faridani, H.M. & Trabucco, D. (2018) “Damping Technologies for Tall Buildings.” CTBUH Journal, 3, pp. 42–47. Available at: https://global.ctbuh.org/resources/papers/3795-Lago_DampingTechnologies.pdf
Larsen, R., Berahman, F. & Aswegan, K. (2024) “Building Performance Achieved.” STRUCTURE Magazine, (June). Available at: https://www.structuremag.org/article/building-performance-achieved/
Malott, D., Robertson, L., Hiei, K. & Werner, H. (2015) “Next Tokyo 2045: A Mile-High Tower Rooted in Intersecting Ecologies.” CTBUH Journal, 2015(2), pp. 30–35. Available at: https://global.ctbuh.org/resources/papers/download/2335-next-tokyo-2045-a-mile-high-tower-rooted-in-intersecting-ecologies.pdf
Mitchell, A. (2025) Why In The World Does Chicago O’Hare Have So Many Runways? Simple Flying. Available at: https://simpleflying.com/why-chicago-ohare-so-many-runways/ [Accessed: July 2025]
Moon, K.S., Connor, J.J. & Fernandez, J.E. (2007) “Diagrid Structural Systems for Tall Buildings: Characteristics and Methodology for Preliminary Design.” The Structural Design of Tall and Special Buildings, 16(3), pp. 205–223. https://doi.org/10.1002/tal.311
Moon, K.S. (2019) “Conjoined Tower Structures for Mile-High Tall Buildings.” International Journal of High-Rise Buildings, 8(1), pp. 29–36. https://doi.org/10.21022/IJHRB.2019.8.1.29
National Fire Protection Association (2024) NFPA 101: Life Safety Code. 2024 ed. Quincy, MA: NFPA.
Nnamani, N. (2012) Strategies for Mitigating Wind-Induced Motion in Tall Buildings through Aerodynamic and Damping Modifications. Master’s thesis, Massachusetts Institute of Technology (MIT). Available at: http://hdl.handle.net/1721.1/74411
Parker, D. & Wood, A. (2013) The Tall Buildings Reference Book. Abingdon: Routledge. https://doi.org/10.4324/9780203106464
Peirce, K. (2023) Structural Design Considerations for Super-Tall Buttressed Core Structure: The Burj Khalifa. Master’s thesis, Kansas State University. Available at: https://krex.k-state.edu/items/a5b17f96-8a88-4156-b806-e28225eeb529
Pomponi, F., Saint, R., Arehart, J.H., Gharavi, N., & Bernardino, D. (2021) “Decoupling Density from Tallness in Analysing the Life Cycle Greenhouse Gas Emissions of Cities.” npj Urban Sustainability, 1, https://doi.org/10.1038/s42949-021-00034-w
Poon, D., Shieh, S., Joseph, L., & Chang, C. (2004) “Structural Design of Taipei 101, the World’s Tallest Building.” Proceedings of the CTBUH 2004 World Congress, Seoul, Korea, pp. 271–278. Available at: https://global.ctbuh.org/resources/papers/download/1650-structural-design-of-taipei-101-the-worlds-tallest-building.pdf
Purdue University (2002) Intro to Structural Motion Control: Chapter 4 — Tuned Mass Damper Systems. Purdue University. Available at: https://pdf4pro.com/view/intro-to-structural-motion-control-purdue-university-6d2616.html [Accessed: July 2025]
Simiu, E. & Scanlan, R.H. (1996) Wind Effects on Structures: Fundamentals and Applications to Design. 3rd ed. New York: Wiley-Interscience.
Smith, R. & Willford, M. (2008) “Damping in Tall Buildings – Uncertainties and Solutions.” IABSE Congress Report, 17th Congress of IABSE, Chicago, 2008, pp. 66–73. https://doi.org/10.2749/222137908796225618
Stravitz, D. & Gray, C. (2002) The Chrysler Building: Creating a New York Icon, Day by Day. New York: Princeton Architectural Press.
Whitehead, T. (2017) Three New York Skyscrapers that Wouldn’t Exist without High-Strength Concrete. Available at: https://www.the-possible.com/three-new-york-skyscrapers-wouldnt-exist-without-high-strength-concrete/ [Accessed: July 2025]
Weismantle, P. & Stochetti, A. (2015) “Case Study: Kingdom Tower, Jeddah.” Proceedings of the CTBUH 2015 World Congress, Dubai. Available at: https://global.ctbuh.org/resources/papers/download/2384-case-study-kingdom-tower-jeddah.pdf
Wu, L., Farzadnia, N., Shi, C., Zhang, Z., & Wang, H. (2017) “Autogenous Shrinkage of High-Performance Concrete: A Review.” Construction and Building Materials, 149, pp. 62–75. https://doi.org/10.1016/j.conbuildmat.2017.05.064
Zienkiewicz, O.C., Taylor, R.L. & Zhu, J.Z. (2005) The Finite Element Method: Its Basis and Fundamentals. 6th ed. Oxford: Elsevier Butterworth-Heinemann.
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