From Sullivan's Wainwright to the Burj Khalifa. The Chicago school, the curtain wall, the tube structure, the supertall race, and the strange new world of the pencil tower. The architecture of vertical ambition.
A skyscraper is not a tall building. It is a tall building made possible by three specific 19th-century inventions — the steel frame, the safety elevator, and the central HVAC system — that together permitted occupied space to rise hundreds of metres above the ground.
The skyscraper was invented in Chicago in the 1880s and perfected in New York in the 1920s and 1930s. For a century after that, the world's tallest buildings were American. The shift after 2000 — first to East Asia, then to the Gulf — has been one of the visible pieces of the realignment of global capital. The Empire State Building (1931) was the world's tallest for 41 years; the Burj Khalifa (2010) is approaching 16 years and may be supplanted by the Jeddah Tower (estimated completion 2028, ~1,000 m).
This deck covers the technology (the curtain wall, the tube structure, the mega-bracing), the canonical buildings (Sears, the Empire State, the World Trade Center, the supertalls), the new typologies (the supertall, the pencil tower), and the working economics. The aim: to look at any tall building and read its structural and historical logic from the street.
The threshold has moved over time. In 1880 a 10-storey building was a skyscraper; by 1930 it took 30 storeys; by 2000 it took 50; by 2026 the working term is "supertall" (300+ m) and "megatall" (600+ m).
The Council on Tall Buildings and Urban Habitat (CTBUH) — the field's authoritative body, founded at Lehigh University in 1969, now headquartered in Chicago — uses these working definitions:
| Tall building | 14+ floors, ~50m+ |
| Supertall | 300m+ / ~75 floors |
| Megatall | 600m+ / ~150 floors |
| Tallest 2026 | Burj Khalifa, 828m / 163 floors |
| Tallest US, 2026 | One World Trade Center, 541m |
| Supertall count, 2010 | ~50 globally |
| Supertall count, 2026 | ~250 globally |
The "height" measurement is itself contested. CTBUH uses three measures: architectural height (to the architectural top, including spires but not antennas — the Empire State's main figure); height to highest occupied floor (which excludes ornamental peaks); and height to tip (including everything). The three sometimes give different rankings. The Petronas Towers vs. Sears Tower argument of the late 1990s — Petronas was taller architecturally but shorter occupied — turned on which measure was authoritative.
The geographic pattern of supertalls has shifted. In 1995, ~70% of the world's tallest 100 buildings were in the US. In 2026, ~70% are in East Asia and the Gulf, with China alone accounting for ~50%. The American century of vertical building was 1880–1990; the Asian century of vertical building has been 1990–present.
The skyscraper was invented in Chicago in the decade after the Great Fire of 1871. The fire had cleared the central business district; the rebuilding produced the world's first concentration of office buildings using metal-frame construction.
The technological elements:
The steel frame. Until ~1880, tall buildings were limited by the strength of their masonry walls. The 16-storey Monadnock Building in Chicago (1891) had ~6-foot-thick load-bearing brick walls at street level — taking up valuable floor area, expensive to construct. The shift to a steel skeleton — first iron, then steel — let the building's weight transfer through a frame, with the walls becoming non-load-bearing curtains. The Home Insurance Building (William Le Baron Jenney, Chicago, 1885), 10 storeys, is the canonical "first skyscraper" — though several earlier buildings could also claim the title and the precise definition is debated.
The safety elevator. Elisha Otis demonstrated his safety elevator (with the automatic brake that prevented free-fall in case of cable failure) at the 1854 New York World's Fair. The first commercial installation was in the Haughwout Building (Manhattan, 1857). By 1880 the elevator was reliable enough to be standard in tall buildings. Without it, no occupant would walk up 15 floors to an office.
Reliable plumbing, heating, lighting. Steam heat (delivered through pipes from a central boiler), gas lighting (replaced from ~1895 by electric), elevator-pumped water — by 1900 a reliable urban infrastructure could support tall-building occupation.
The Chicago architects: William Le Baron Jenney (the engineer), Louis Sullivan and Dankmar Adler (Sullivan was the architect, Adler the engineer; their firm produced ~180 buildings 1881–1895), Daniel Burnham, John Wellborn Root. Their working principle, articulated by Sullivan in his 1896 essay "The Tall Office Building Artistically Considered": form ever follows function.
The Chicago school's signature building: the Wainwright Building in St Louis (Sullivan and Adler, 1891), 10 storeys, vertical-fluted ornamentation expressing the building's underlying steel frame. Sullivan's Carson Pirie Scott Store (Chicago, 1899) extended the principles. By 1910 the Chicago school had set the template that New York and the rest of America would follow.
Louis Sullivan's 1896 essay "The Tall Office Building Artistically Considered" is one of the founding documents of modernist architecture. The argument:
The tall office building has a logical structure: a base (street level, ground-floor commerce, lobby), a shaft (repetitive office floors), and a capital (the top, which is where mechanical equipment lives and where the building's silhouette announces itself to the city). This three-part division — modelled on the classical column — should be expressed in the building's elevation.
The famous formulation: "It is the pervading law of all things organic and inorganic, of all things physical and metaphysical, of all things human and all things superhuman, of all true manifestations of the head, of the heart, of the soul, that the life is recognizable in its expression, that form ever follows function. This is the law."
The Bauhaus and the European modernists later quoted Sullivan's slogan as their own. They used it more rigidly than Sullivan had — Sullivan was, despite his rationalist rhetoric, an extravagant ornamentalist; his terra-cotta capitals on the Wainwright Building and the Auditorium Building (Chicago, 1889) are among the most-elaborately-decorated façades in American architecture. Sullivan saw no contradiction: the function generated the form, but the form could carry ornament that expressed and enriched it.
Sullivan's career declined sharply after 1900. The 1893 World's Columbian Exposition in Chicago, which Sullivan considered an aesthetic catastrophe (its Beaux-Arts neoclassicism dominated by Burnham), redirected American architectural taste away from the Sullivan-Wright Prairie tradition. By 1920 Sullivan was poor, drinking, and largely without commissions. He died in 1924; his protégé Frank Lloyd Wright wrote about him for the rest of Wright's career.
Sullivan's monument is the Wainwright. His pupil Wright went on to a 60-year career; Sullivan's direct architectural influence in the 20th century was largely through Wright. But the slogan — form follows function — outlived him and still functions, often misquoted, as the working motto of rationalist design.
By 1900 the skyscraper had migrated from Chicago to New York. The Manhattan grid, the dense Manhattan land economics, and the New York commercial appetite produced a faster and more extreme vertical expansion than Chicago.
Flatiron Building (Daniel Burnham, 1902). Steel-frame triangular tower at 23rd Street where Broadway crosses Fifth Avenue. The most-photographed early Manhattan skyscraper.
Singer Building (Ernest Flagg, 1908). Briefly the world's tallest. Demolished 1968 — the tallest building ever voluntarily demolished, until 1 Beekman Street disrupted that record.
Metropolitan Life Tower (Napoleon LeBrun & Sons, 1909). 50 storeys, modelled on the Campanile of San Marco. Briefly the world's tallest.
Woolworth Building (Cass Gilbert, 1913). 60 storeys, Gothic ornament, terra cotta cladding. The "Cathedral of Commerce." The world's tallest 1913–1930.
The 1916 New York Zoning Resolution — the first comprehensive zoning code in the United States — regulated tall buildings through "setbacks." Buildings could rise vertically up to a fixed height, then had to set back to admit light to the street below. The setback rules produced the characteristic "wedding cake" silhouettes of 1920s Manhattan skyscrapers — the building rises straight, then steps back, then rises again, then steps back, in a series of progressively-smaller masses up to a tower.
The 1916 ordinance was modeled on Equitable Life Building (1915) — the 38-storey block at 120 Broadway whose vertical walls cast permanent shadow on the streets below, prompting the regulatory response. The ordinance shaped Manhattan's skyline for the next 45 years; the 1961 zoning revision (which substituted floor-area-ratio limits) eventually replaced it.
The architects of the 1920s Manhattan boom: Cass Gilbert, Ralph Walker, Raymond Hood, William Van Alen. They worked for corporate clients in commercial competition; they produced an enormous body of skyscrapers (the Bowery Savings Bank, the Bank of Manhattan Trust, the Daily News Building, the New York Telephone Building) that constitute the foundation of the Manhattan skyline.
The canonical skyscraper. Shreve, Lamb & Harmon designed it; Starrett Brothers and Eken built it. Construction began in March 1930 and the building opened on May 1, 1931 — 14 months from groundbreaking to opening, faster than any building of its scale before or since.
The numbers:
| Floors | 102 |
| Roof height | 381m / 1,250ft |
| Tip including antenna | 443m / 1,454ft |
| Floor area | ~257,000m² / 2.77 million ft² |
| Workers at peak | ~3,400 |
| Construction time | 410 days |
| Cost | ~$41M (1931); ~$830M (2026) |
| World's tallest | 1931–1972 (41 years) |
The construction was extraordinary. Steel was delivered to site within hours of being cast at the Bethlehem Steel mills in Pennsylvania; the construction logistics resembled Henry Ford's assembly line. The 102-storey structural skeleton was complete in 23 weeks. The exterior cladding, the elevators, the interior fitout were finished in another 36 weeks.
The Empire State opened into the Great Depression and was largely empty for its first decade — nicknamed "the Empty State Building" through the 1930s. It became profitable in the 1950s. The 1933 King Kong sequence (and the 1976 remake) gave the building its iconic cinematic status. By the 1970s it was regarded as the canonical American skyscraper, even after the Sears and the World Trade Center surpassed it in height.
The 2010s restoration ($550M) brought the building's energy performance into 21st-century compliance — a working model for what restoration of the mid-century commercial skyscraper might look like at scale. The building remains in active commercial use; the 86th-floor observation deck attracts ~4 million visitors a year.
The Empire State Building is, by general consent, the most-loved skyscraper. It is not the tallest, not the most-architecturally-distinguished, not the most-engineering-advanced. It is the one whose proportions, silhouette, and Manhattan-skyline placement happen to add up to a building the public has cared about for nearly a century.
The other side of the 1930 Manhattan competition. The Chrysler Building (William Van Alen, 1930) was — for ten months in 1930–31, before the Empire State opened — the world's tallest building.
The race between the Chrysler and 40 Wall Street (the Bank of Manhattan Trust, by H. Craig Severance) is one of the most-famous architectural competitions in American history. Van Alen and Severance had been partners until a 1924 falling-out; both buildings were rising in 1929 with planned heights that would have made them the world's tallest. Severance announced 40 Wall Street at 282 metres; Van Alen secretly fabricated a 56-metre stainless-steel spire inside the Chrysler's crown, hoisted it through the dome in 90 minutes in October 1929, and topped out the building at 319 metres — making the Chrysler indisputably tallest, by a margin Severance could not match.
The Chrysler held the title for less than a year before the Empire State opened. Van Alen never received another major commission — Walter Chrysler refused to pay him the agreed fee and accused him of taking kickbacks; Van Alen sued and eventually won, but his career ended.
The building itself is the canonical Art Deco skyscraper. The seven-tier crown of stainless steel triangles (modelled on Chrysler hubcaps); the eagle gargoyles at the corners (modelled on Chrysler hood ornaments); the lobby's African red marble and Cuban mahogany; the murals of transportation history. The Chrysler is more decoratively ambitious than the Empire State and considerably more idiosyncratic.
The 1929 stock-market crash arrived between Chrysler's groundbreaking (1928) and its opening (1930). The Chrysler company itself cancelled plans for a second tower nearby; the Empire State's developer pushed forward despite the crash. Both buildings stood through the Depression as monuments to the late-1920s Manhattan ambition that the rest of the decade would not repeat.
The Chrysler remains in active commercial use; the lobby is open to the public during business hours. Van Alen is buried in Brooklyn under a modest stone.
The postwar skyscraper looks fundamentally different from its prewar predecessors. The reasons: the curtain wall, the structural-steel framing innovations, and the Mies-van-der-Rohe-led shift in aesthetic.
The curtain wall. A non-load-bearing exterior cladding hung from the building's structural frame. By the 1950s, prefabricated curtain-wall panels (typically aluminum-framed glass) could be hoisted to upper floors and installed quickly, replacing the laborious masonry cladding of prewar towers. The Lever House (Skidmore, Owings & Merrill, NYC, 1952) was the first major American glass-curtain-wall office tower. The Seagram Building (Mies, 1958) was the architect-respected masterpiece. By 1960 the curtain wall was the default Manhattan tower exterior.
The structural innovations. Two main developments. Welded steel framing (replacing earlier riveted construction) was faster and produced more rigid joints. Composite construction (concrete-filled steel columns, steel beams encased in concrete) allowed taller buildings with less structural weight.
The aesthetic shift. The prewar setback ziggurat (the "wedding cake") gave way to the postwar plinth-and-tower. A low base (often a colonnade or open plaza, fulfilling the 1961 zoning's plaza-bonus provisions) supported a single rising glass volume that ran straight to the top. Lever House, the Seagram, the World Trade Center, the Sears, and most postwar skyscrapers used variations of this typology.
The 1961 NYC Zoning Resolution. Replaced the 1916 setback rules with floor-area-ratio (FAR) limits and plaza bonuses. Developers could build higher (and forgo setbacks) if they provided open public plazas at street level. The result was the post-1961 Manhattan typology — slim glass tower, large empty plaza below — that William Whyte's Social Life of Small Urban Spaces (1980) documented as mostly uninhabited and badly designed.
The postwar skyscraper diffused worldwide. By 1970 every major American city had an SOM glass-curtain-wall office tower; by 1980 every major Asian city did too. The aesthetic became the default international corporate vocabulary.
The single most important structural innovation in skyscraper history. Fazlur Rahman Khan (1929–1982), Bangladeshi-American structural engineer at Skidmore, Owings & Merrill, developed the "tube" structural system in the 1960s and applied it to the buildings that defined the late-20th-century supertall.
The principle: instead of a building behaving like a vertical cantilever beam (with all the lateral wind and seismic load resisted by an internal "core"), conceive of the building's exterior as a continuous tube — a hollow steel-and-concrete cylinder rising from the ground, with closely-spaced exterior columns and deep spandrel beams forming a structurally-integrated outer shell. The tube takes both gravity and lateral loads; the interior can be free of structural columns.
The result is a much more efficient building. A traditional core-only structure of comparable height would require ~30 lb of steel per square foot of floor area; a tube can do it with ~20 lb. For 100-storey buildings this is the difference between economic feasibility and infeasibility.
Khan's signature buildings:
DeWitt-Chestnut Apartments (Chicago, 1965). The first concrete tube — Khan's prototype.
John Hancock Center (Chicago, 1969, 100 floors, 344m). The "X-braced" tube — Khan added giant exterior X-bracing across the building's elevation, which made the structure 30% more efficient and became the building's visual signature. The Hancock's tapering profile and visible diagonal bracing are direct expressions of structural logic.
Sears Tower (Chicago, 1973, 108 floors, 442m). The "bundled tube" — nine adjacent square tubes of different heights forming a single building. The structural system allowed extremely large floor plates at the base while tapering toward the top. World's tallest 1973–1998. Renamed Willis Tower 2009.
Khan's other refinements: the "tube-in-tube" (a structural tube inside another structural tube, used for the Brunswick Building, Chicago, 1965); the "framed tube" (the World Trade Center used a related system). Khan died young, at 52, in 1982 — but his work changed how every supertall building since has been engineered. Adrian Smith, the SOM architect of the Burj Khalifa, has called Khan "the father of the modern skyscraper."
Designed by Minoru Yamasaki and Emery Roth & Sons; structural engineering by Worthington-Skilling (later Skilling, Helle, Christiansen, Robertson); built 1966–1973. The North Tower opened 1972, the South Tower 1973. Each was 110 storeys, 415m and 417m. World's tallest 1972–1974 (when Sears Tower opened).
The structural system was a "framed tube" — closely-spaced exterior steel columns (one every 1m) connected by deep spandrel beams, forming a continuous outer skeleton. The exterior load-bearing walls allowed extremely efficient floor plates: 60m × 60m square plates, with 8m × 13m core in the centre, leaving a 19m unobstructed perimeter zone. The 200,000-tonne steel structure carried roughly 50 storeys' worth of trade-organisation tenants per tower.
Yamasaki was an unusual choice. He was Japanese-American, had survived World War II internment, and had built mostly small commissioned architectural projects before the WTC. He hated heights — the WTC's narrow window-slits (only 56cm wide) reflected his preference for not seeing how tall the building was. The buildings were architecturally divisive; many architects considered them aesthetically embarrassing (Lewis Mumford famously called them "elegantly designed glass-and-metal filing cabinets"); the public tolerated rather than loved them; the rooftop observation deck and Windows on the World restaurant gave them their popular-culture identity.
The 11 September 2001 attacks destroyed both towers. The North Tower was struck at 8:46 AM by American Airlines Flight 11 between floors 93 and 99; the South Tower was struck at 9:03 AM by United Airlines Flight 175 between floors 77 and 85. The South Tower collapsed at 9:59 AM (56 minutes after impact); the North Tower collapsed at 10:28 AM (102 minutes after impact). 2,606 people died inside the towers and on the surrounding plaza, plus 246 on the four hijacked aircraft and 125 at the Pentagon.
The post-attack analysis (by NIST, 2005) attributed the collapses to the combination of structural damage from the impact, the fires from the jet fuel and contents (which weakened steel above ~600°C — the WTC's fire protection had been damaged by the impacts), and progressive failure of the truss-supported floors. The buildings had been designed to survive a Boeing 707 impact at 290 km/h; the actual impacts were 600+ km/h Boeing 767s with full fuel loads.
The site has been substantially rebuilt. One World Trade Center (David Childs/SOM, 2014) — 541m, the tallest US building. The 9/11 Memorial (Michael Arad, 2011) occupies the original tower footprints. The Oculus transportation hub (Calatrava, 2016).
By the late 1990s the world's tallest building was no longer in America. The Petronas Towers (Kuala Lumpur, César Pelli, 1998) — twin 88-storey, 452m towers connected by a sky bridge at the 41st-42nd floors — were the first non-American world's-tallest in over a century.
The CTBUH height-measurement controversy: the Petronas's architectural top (including its decorative spire) was 452m — taller than the Sears Tower's 442m roof height. But the Sears Tower's highest occupied floor was higher than Petronas's. The CTBUH committee in 1998, after extensive deliberation, ruled the Petronas tallest by architectural-height measure. The decision marked the formal end of American dominance of the skyscraper-height title.
The 2000s and 2010s saw a steady eastward shift:
Taipei 101 (C.Y. Lee, 2004). 101 floors, 508m. World's tallest 2004–2010. The "tuned mass damper" — an 660-tonne steel sphere suspended from cables at the building's top, swinging counter to wind oscillations to reduce occupant sway — is the building's engineering signature and the first such damper to be a public attraction (visible on the 87th-92nd floor observation deck).
Burj Khalifa (SOM/Adrian Smith, Dubai, 2010). 163 floors, 828m. World's tallest since 2010. Built using a buttressed central core — three radiating buttresses bracing a hexagonal central mast — that allows the building's progressive setbacks toward the top while maintaining structural integrity. The Burj is currently 50% taller than the next-tallest completed building.
Shanghai Tower (Gensler, 2015). 632m, second-tallest in 2026. Twisted form (rotates 120° from base to top) reduces wind loading by ~24%; the double-skin curtain wall encloses 21 atrium-sky-gardens between floors; the tuned mass damper is the world's largest.
Lotte World Tower (KPF, Seoul, 2017). 555m. South Korea's tallest.
Ping An Finance Center (KPF, Shenzhen, 2017). 599m.
Goldin Finance 117 (P&T Group, Tianjin, structural completion 2015, halt-in-progress, planned 597m).
The Jeddah Tower (Adrian Smith + Gordon Gill, Saudi Arabia, projected completion 2028, planned 1,000m+). When complete, it will be the world's first kilometre-tall building.
The current world's tallest, since 2010. Adrian Smith was the lead architect at SOM (he left to form his own firm during the building's design). William Baker was the structural engineer. Construction began in 2004 and the building opened in January 2010.
| Floors | 163 occupied + spire |
| Architectural height | 828m / 2,717ft |
| Highest occupied floor | 584m |
| Floor area | ~334,000m² |
| Total cost | ~$1.5 billion |
| Workers | ~12,000 daily peak |
| Construction time | ~6 years |
| Sway at top in wind | ~1.5m |
The structural system: a "buttressed core" of reinforced concrete. Three Y-shaped buttresses radiate from a central hexagonal core, bracing it against wind loads in three directions. The plan rotates and tapers as it rises — the floor plate at level 100 is much smaller than at level 1; at level 156 the structure transitions to a steel pinnacle that rises to the architectural top.
The progressive setbacks — 27 of them, distributed around the three buttresses — are not decorative. They are wind-engineering: the setbacks "confuse" the wind by changing the building's cross-section at every level, preventing the resonant vortex shedding that would otherwise build dangerous oscillations. Calculation, full-scale wind-tunnel testing, and a tuned mass damper at the top together produce a building whose maximum sway in the worst expected wind is ~1.5 metres at the top — about 0.2% of the building's height.
The cooling load is enormous (Dubai is hot; the building is enclosed in glass; ~12,000 people occupy it at peak). The HVAC system uses condensate from the cooling plant for irrigation in the surrounding park (~14 million litres a year of cold air-conditioning condensate becomes irrigation water); the chilled water is partly cooled at night when ambient temperatures are lower.
The Burj is unprofitable. Most of its residential floors sat empty for years after opening; office occupancy has been mixed. Dubai's ruler Mohammed bin Rashid al Maktoum named it after Sheikh Khalifa of Abu Dhabi after Abu Dhabi bailed out the project in 2009 — the building's name was changed from "Burj Dubai" to "Burj Khalifa" at the opening ceremony.
The Burj Khalifa established that 800-metre-plus buildings are technically and economically feasible. The Jeddah Tower will test 1,000 metres. Whether that's the upper limit of the supertall era or only a waystation is unresolved.
The 21st-century New York innovation. The "pencil tower" or "supertall slender" is an extremely tall residential building on a small footprint — height-to-width ratios of 10:1 or higher (compared to ~7:1 for the Empire State). The form depends on advanced structural engineering, particularly tuned mass dampers and outrigger systems that resist wind loading on a narrow building.
The pencil-tower phenomenon is concentrated on Manhattan's "Billionaires' Row" along 57th Street, where developers have used air-rights consolidation (purchasing the unbuilt floor area from neighbouring small buildings) to build slim ultra-luxury residential towers on midblock parcels.
432 Park Avenue (Rafael Viñoly, 2015). 426m, 96 floors. Height-to-width ratio of 15:1. Designed as an extruded hollow square tube; the floor plates are 28m × 28m. Famous for sway-related structural problems (water leaks, elevator failures, residents' complaints) that emerged after occupancy.
111 West 57th Street / Steinway Tower (SHoP Architects, 2021). 435m, 84 floors. Height-to-width ratio of 24:1 — the world's most-slender skyscraper. The west and east faces are 18m wide; the building rises ~24 times that. The structure is a steel-reinforced concrete buttress wall on the west, a column line on the east, and four belt trusses tying them together at intervals.
Central Park Tower (AS+GG, 2020). 472m, 98 floors. Tallest residential building in the world. Cantilevers over the smaller Art Students League building to its south.
One57 (Christian de Portzamparc, 2014). 306m, 75 floors. The pencil-tower template; the first of the new generation.
53 West 53rd / MoMA Tower (Jean Nouvel, 2019). 320m, 77 floors. Diagonal exoskeleton bracing; cantilevers over the Museum of Modern Art's expansion.
The economics: pencil towers monetise air rights. A small midblock parcel that can hold 10 floors of normal building can, by purchasing unused FAR from neighbouring lots, support a 90-floor tower selling at the highest residential prices in the world. Penthouse floors at 432 Park sold above $90 million; the upper floors of Central Park Tower above $250 million. The buildings are largely empty most of the year — pied-à-terre or speculative investment for global ultra-wealthy buyers.
The political reaction has been substantial. Manhattan Community Board 5 has opposed several pencil-tower projects; the 2019 NY State legislative push to require taxes on non-resident foreign-owned luxury units was a direct response. The pencil-tower era continues but at reduced volume since 2022.
The 2010s and 2020s have been China's supertall decades. Of the 250 supertalls completed worldwide as of 2026, ~125 are in China.
The drivers:
Urbanisation. ~250 million Chinese moved from rural to urban areas between 2000 and 2020 — the largest urban migration in human history. New cities (Pudong in Shanghai, Shenzhen's expansion, Chongqing's interior development) needed housing and office stock at scale.
Provincial competition. Chinese provinces and cities have competed to build taller buildings as expressions of local economic prestige. Many of the supertalls in second-tier Chinese cities were government-supported beyond the buildings' commercial demand.
Construction capacity. China's vertical-construction industry (China State Construction Engineering, China Communications Construction, etc.) became the world's largest by the 2010s. The labor, material, and engineering capacity to build supertalls at scale was concentrated in Chinese firms.
The signature buildings:
Shanghai Tower (Gensler, 2015, 632m). Twisted form, 9 vertical zones of sky-gardens.
Ping An Finance Center (KPF, Shenzhen, 2017, 599m).
CITIC Tower / China Zun (TFP Farrells, Beijing, 2018, 528m).
Tianjin CTF Finance Center (SOM, 2019, 530m).
Guangzhou CTF Finance Center (KPF, 2016, 530m).
The 2021–2024 cooling: Chinese central authorities issued circulars in 2021 and 2022 restricting new super-tall construction (over 500m) for safety, energy, and political-image reasons. Several proposed projects were cancelled or shortened (Wuhan Greenland Center, originally 636m, completed at 475m in 2023). The supertall pipeline through 2030 in China is substantially smaller than it was in 2018.
The energy and operational reality: many Chinese supertalls have low occupancy. The 2018 Real Capital Analytics study found that the second-tier Chinese supertall office buildings averaged 60% occupancy at completion; some never reached 80%. The buildings express prestige rather than working economic demand.
Whether China's supertall building boom turns out to have been justified by working economics or to have been malinvestment driven by provincial-political competition is one of the open questions of contemporary Chinese economic history.
What goes into a supertall.
Structural systems. The current supertall toolkit:
· Buttressed core (Burj Khalifa). Reinforced-concrete core with three radiating wings; very stiff, very efficient at extreme heights.
· Outrigger and belt truss (Taipei 101, Shanghai Tower). The central core is connected to perimeter "mega-columns" by stiff outriggers at intermediate floors; the outriggers force the perimeter to act with the core in resisting wind loads.
· Diagrid (Hearst Tower NYC, the Gherkin London, CCTV Beijing, Bank of China Hong Kong). Diagonal exterior bracing replaces the traditional grid of vertical columns; the diagonals carry both gravity and lateral loads. Saves ~20% steel for buildings of comparable height.
· Mega-bracing (Hancock Tower Chicago). Giant exterior X-bracing visible on the elevation; structurally efficient and architecturally distinctive.
Wind engineering. All supertalls undergo extensive wind-tunnel testing. Boundary-layer wind tunnels (the Western University wind tunnel in Canada is a leading facility) test scale models for ~30 different wind directions, simulating the local wind climate at each. The results determine: the building's structural sizing, the cladding's pressure-resistance specifications, the placement of dampers, and (sometimes) modifications to the building's form.
Tuned mass dampers. Large weights at the top of the building, designed to oscillate counter to building sway and dissipate energy. Taipei 101's 660-tonne sphere is the visible canonical example; Shanghai Tower's TMD is the largest in the world.
Foundation. Supertalls bearing 500,000+ tonnes need extraordinary foundations. The Burj Khalifa rests on 192 friction piles, each 1.5m diameter and 50m deep, transferring load to the underlying limestone bedrock. The foundation construction took 6 months.
Vertical transportation. Elevator engineering is the limiting practical constraint. Conventional elevators have a maximum useful travel of ~450m (cable mass becomes prohibitive); supertalls use sky-lobby systems (express elevators to mid-building lobbies, local elevators from there) and the new generation of cable-less elevators (Multi by ThyssenKrupp, in development) that may eventually allow horizontal as well as vertical travel.
Tall buildings are problematic from a climate-emissions perspective. The reasons:
Embodied carbon. A supertall contains enormous quantities of cement (high-carbon production), steel (high-carbon production), aluminum (high-carbon production), and glass (moderate-carbon, replaced often). The Burj Khalifa's embodied carbon is estimated at ~330,000 tonnes CO₂ — roughly the lifetime emissions of 50,000 small cars.
Operational energy. Tall buildings consume more energy per square metre than low-rise. Vertical transportation, water pumping, the wind-driven envelope load, the structural mass — all add to operating energy. A 100-storey office building in a temperate climate uses ~1.5–2× the energy per m² of a comparable low-rise building.
Glass-curtain-wall problem. The mid-century to 2010s default of fully-glazed exteriors is thermally awful. Glass conducts heat ~6× faster than insulated wall; glass admits unwanted solar gain in summer. Even high-performance double-glazed units lose 4–10× more heat than insulated wall. Most postwar supertalls are envelope-thermal disasters.
The mitigations:
High-performance envelopes. Triple glazing, low-emissivity coatings, double-skin facades (the Shanghai Tower's two glass envelopes with sky gardens between them is the canonical demonstration), shading devices, motorised blinds.
Mixed-use programming. A supertall with a mix of office, residential, and hotel uses can balance peak demands on heating, cooling, and ventilation systems through the day, reducing total energy.
On-site energy generation. Building-integrated photovoltaics, wind turbines (largely a marketing gesture — small wind turbines generate trivial energy compared to building loads), and combined heat-and-power systems.
Mass timber alternatives. The 2017–2025 emergence of cross-laminated timber (CLT) for tall-building structure as an alternative to steel/concrete. The Mjøstårnet (Brumunddal, Norway, 2019, 85m) is the tallest mass-timber building. A 25–30 storey CLT building has ~50% lower embodied carbon than a steel-and-concrete equivalent.
The supertall in 2026 is increasingly hard to justify on climate grounds. The 2020s have seen growing arguments that the era of new supertall construction should end — that retrofit of existing tall buildings (lower carbon than new construction) is the appropriate climate-conscious response. The political-economic momentum behind new supertalls (especially in the Gulf and East Asia) has not yet conceded to this argument.
The skyscraper economics is more interesting and less obvious than it sounds.
Land cost. The simplest argument. In high-land-cost cities (Manhattan, Hong Kong, Tokyo, central London), an additional floor of office or residential space costs only the marginal construction cost — a small fraction of the cost of acquiring an additional ground-floor footprint of comparable area. The skyscraper amortises expensive land over many floors.
Density and concentration. Modern service economies — finance, law, consulting, media — depend on extremely dense face-to-face networks. The skyscraper enables the dense central business district. Manhattan's continuing financial-services dominance, Hong Kong's role in Asian finance, central London's professional-services concentration — all depend on dense vertical building.
Prestige and signalling. A "trophy" skyscraper can be a real-estate marketing instrument. The corporate tenant who occupies the top-floor of the city's tallest building communicates institutional status; the developer who builds it communicates capacity. Many supertalls are partly trophy projects whose pure financial returns are low but whose signalling and political-economic returns are substantial.
Diminishing returns. The structural cost per floor rises rapidly with height. A 30-storey building costs ~$200/ft² of office space to construct in 2026; a 100-storey building costs ~$400/ft² — twice as much per unit floor area. The marginal cost of the upper floors is high. For most office uses, the optimal building height in a high-land-cost city is 30–60 storeys; only when prestige, residential ultra-luxury, or specific structural advantages obtain do supertalls make pure-economic sense.
The "skyscraper index." The economist Andrew Lawrence's 1999 observation that the world's tallest buildings have historically been completed at the peaks of economic cycles, just before recessions. The Empire State (1931), the World Trade Center (1973), the Sears (1974), the Petronas (1998), the Burj Khalifa (2010 — opened during the GFC) — each completion roughly coincided with a major economic downturn. The argument is partly about long planning lags (skyscrapers take 5–10 years from inception to opening, long enough that the economic conditions that justified them have changed) and partly about hubris-driven over-investment at cycle peaks.
The pattern continues: most analysts identify the post-2008 China supertall boom as a continuation of the same pattern. The Jeddah Tower's completion in 2028 will be a useful test case.
Until ~2000, supertalls were almost exclusively office buildings. Since then the residential supertall has become a major typology — particularly in Manhattan, Miami, Hong Kong, Singapore, and Dubai.
The reasons:
Land prices in luxury markets. A penthouse on the 80th floor of a Manhattan tower with Central Park views is among the world's most-expensive residential real estate. The marginal economics work: building higher costs more per floor, but the upper floors command premium prices that more than compensate.
Tax and air-rights structures. The Manhattan air-rights system, in particular, has enabled the pencil-tower phenomenon. Smaller mid-block lots can be combined with neighbouring lots' unused FAR (Floor Area Ratio) to support buildings with ratios their actual lots could not.
Global ultra-wealthy migration. The post-2000 growth of the global ultra-rich (UHNWI count grew from ~80,000 in 2000 to ~600,000 in 2025) has produced demand for ultra-luxury residential properties as wealth-storage instruments, often left empty. New York's pencil-tower penthouses and Dubai's Burj Khalifa upper floors serve this demand.
Hong Kong's vertical residential tradition. Hong Kong's land scarcity has produced a dense residential-tower urbanism unique among major cities — most Hong Kong residents live in 30–60-storey towers. The city's K21 Cyberport (2003) and continuing redevelopment projects extend the tradition.
The residential-supertall problems:
Sway and noise. Pencil-tower residents experience perceptible sway in winds — typically 0.3–1m at the upper floors of 80–100-storey buildings — and structural noise. 432 Park Avenue's structural complaints (water hammer, elevator delays, building creaking) are widely reported.
Empty buildings. Many luxury supertalls have low occupancy. NYC's pied-à-terre tax and similar policies elsewhere are partial responses.
Community displacement. Concentrated luxury supertall construction has displaced lower-cost residents in adjacent neighbourhoods. Manhattan's "Billionaires' Row" has been the canonical example since the early 2010s.
The residential-supertall pipeline is slowing in 2026 relative to the 2015–2020 peak, but the typology has become an established part of the global luxury-real-estate market.
Where the supertalls cluster.
Hong Kong. ~315 supertall and tall buildings in 2026, the densest concentration of high-rise anywhere. The Hong Kong skyline (especially the Central and Wan Chai districts viewed from Kowloon) is canonically photographed. The 2 IFC (KPF, 2003), the Bank of China Tower (Pei, 1990), the Lippo Centre (Paul Rudolph, 1988), the ICC International Commerce Centre (KPF, 2010, 484m).
Manhattan. The original skyscraper city. ~110 supertalls; the canonical American skyline. The Empire State, the Chrysler, One World Trade, Hudson Yards (KPF/Diller Scofidio + Renfro, 2019), the pencil towers of 57th Street.
Shanghai. Pudong's late-1990s and 2000s development: the Oriental Pearl Tower (1994), Jin Mao Tower (SOM, 1999, 421m), Shanghai World Financial Center (KPF, 2008, 492m), Shanghai Tower (Gensler, 2015, 632m). The four towers cluster within 1 km.
Dubai. ~215 tall buildings, almost all built since 2000. Burj Khalifa, Marina district, the Palm Jumeirah hotel towers. The fastest skyline transformation of any major city in human history.
Chicago. The original American skyscraper city. ~120 tall buildings. Willis Tower, John Hancock Center, Trump Tower Chicago (Adrian Smith/SOM, 2009, 423m). The Chicago Architecture Center boat tour is the best architectural-tourism experience in the country.
Tokyo. The Shinjuku, Shibuya, Roppongi, and Marunouchi districts. The 2020s tall-building boom (the Toranomon Hills development, the Azabudai Hills tower at 330m completed 2023). Earthquake regulations limit Japanese building heights more than other supertall regions.
Kuala Lumpur. The Petronas Towers (1998); KL 118 (Pelli/Fender Katsalidis, 2024, 679m, second-tallest in the world).
Shenzhen. The post-2010 Chinese megacity; Ping An Finance Center, KK100, the SEG Plaza tower's 2021 swaying-incident.
Seoul. Lotte World Tower (KPF, 2017, 555m).
London. The Shard (Renzo Piano, 2012, 310m), 22 Bishopsgate (PLP, 2020, 278m). London's tall-building rules limit further supertall growth.
What it's like inside a supertall.
The ear-popping. A fast express elevator from the lobby to the 80th floor changes ambient pressure noticeably; ear-popping is universal. The Burj Khalifa's express elevator covers ~600 vertical metres in 60 seconds.
The wind-driven sway. Even with damping systems, supertalls sway perceptibly in strong winds. Office workers report water in glasses oscillating, hanging cables swinging, light fixtures rattling. At Hong Kong's 88-storey Two IFC, the upper floors sway ~1 metre in typhoons. The sway is structurally safe but psychologically noticeable.
The view dependence. Upper-floor occupants become heavily dependent on the view as their visual environment. A foggy week — when the building is in cloud — produces a peculiar disorientation. Some residents report a kind of altitude depression in extended overcast periods.
The vertical-transportation time. A worker on the 90th floor of a Manhattan supertall spends ~6–8 minutes per day in elevators (lobby to office, lunch trips, end of day). Over a year that's ~30 hours; over a career, ~1,000 hours. Building managers minimise this through sky-lobby systems and elevator scheduling, but the physical reality of vertical commuting time is real.
Emergency egress. Stair evacuation from the 80th floor takes ~45–60 minutes in a controlled drill. The post-9/11 codes (NYC, then federal, then international) require widened stairs, additional independent egress systems, and pressurised stair towers. Most pre-2001 supertalls have been retrofitted; some have not.
Maintenance access. The exterior cladding of a supertall requires regular cleaning, periodic glass replacement, and structural inspection. The Burj Khalifa's exterior maintenance system uses cradles supported from rooftop davits; cleaning the entire exterior takes ~3 months. The work is among the world's highest-paid manual labour and one of its most-dangerous.
Bird strikes. Major issue for fully-glazed supertalls. New York City's Lights Out programme (2018), specifying limited night-lighting during migration seasons, addresses the worst migration-season collisions. The Toronto BirdSafe programme is the leading regulatory response.
The major catalogued failure modes.
Wind sway. The Citicorp Building (Manhattan, 1977, now 601 Lexington) discovered after completion that quartering winds (winds at 45° to the building's primary axes) had been miscalculated. The building was structurally vulnerable to relatively modest hurricane-force winds; the engineer William LeMessurier ordered emergency overnight reinforcement of the bracing in 1978. The episode is a canonical engineering-ethics case study.
Cladding failure. The 2017 Grenfell Tower fire (London, 24 storeys, 72 deaths) was driven by exterior cladding (aluminum-composite ACM panels with combustible polyethylene cores) that allowed fire to propagate up the building's façade. The post-Grenfell regulatory response — banning combustible cladding on tall buildings in many jurisdictions — has driven extensive recladding programmes and is partly why ACM-clad supertalls completed in the 2010s have had mid-life recladding work.
Foundation settlement. The Millennium Tower in San Francisco (2009, 58 floors) has settled ~45cm and tilted ~50cm at the top since opening — driven by the surrounding ground's response to nearby Transbay Transit Center construction. Continuing engineering remediation through the 2020s.
Glass failure. Tempered glass on supertalls has failed by spontaneous breakage (nickel sulfide inclusions in the glass under thermal stress). The Sears Tower has had multiple panel failures over its life. Modern supertalls use heat-soaking processes that reduce but don't eliminate the risk.
Earthquake response. Tall buildings perform variably in earthquakes. The 2011 Tōhoku earthquake (Japan) caused significant non-structural damage to Tokyo's tall buildings (200km from the epicentre); the Roppongi Hills Mori Tower's mass damper performed within design parameters but at extreme limits. Mexico City's 1985 earthquake destroyed several mid-rise buildings (the resonance with the city's lakebed soil amplified mid-frequency oscillations). Modern supertalls in seismic zones are extensively dynamically modelled.
Fire. The 9/11 World Trade Center collapses are the canonical post-impact-fire failures. The Mandarin Oriental Hotel fire (Beijing, 2009, during construction) and the Address Downtown Hotel fire (Dubai, 2015) are the major operational-fire incidents. Modern supertalls have substantially better fire systems than mid-century towers, but high-rise fire remains an extreme operational challenge.
Demolition. Voluntary demolition of major skyscrapers is rare but has occurred. The Singer Building (Manhattan, 1908; demolished 1968 at 187m, the tallest voluntary demolition until 2019). The 270 Park Avenue (Skidmore Owings & Merrill, 1961; demolished 2019–2021 to make way for JPMorgan Chase's new headquarters at 423 metres — currently the largest voluntary skyscraper demolition).
The engineering and architecture of supertalls is concentrated in a small number of large international practices.
Skidmore, Owings & Merrill (SOM). Founded Chicago, 1936. The dominant supertall practice from Lever House (1952) onward. Burj Khalifa, Sears Tower, John Hancock, One World Trade Center, Jeddah Tower (the 2028 kilometre-tall). Three founders of the modern supertall typology — Bruce Graham (architect), Fazlur Khan (engineer), Adrian Smith (architect) — were SOM partners.
Adrian Smith + Gordon Gill Architecture. Smith left SOM in 2006 to form his own firm. Jeddah Tower, Wuhan Greenland Center, Kingdom Centre Tower, Central Park Tower NYC.
Kohn Pedersen Fox (KPF). Founded NYC, 1976. Shanghai World Financial Center, Ping An Finance Center, Lotte World Tower, ICC Hong Kong, 30 Hudson Yards. Generally less aesthetically distinguished than SOM but operationally prolific.
César Pelli. Petronas Towers, Wells Fargo Center, KL 118.
Gensler. Shanghai Tower; one of the world's largest architectural firms; mid-prestige supertall practice.
Foster + Partners. 30 St Mary Axe (the Gherkin), Hearst Tower NYC, Comcast Center Philadelphia, Apple Park (not a supertall but a related typology). Norman Foster's high-tech aesthetic.
Renzo Piano Building Workshop. The Shard (London), New York Times Building, Whitney Museum (not a supertall).
Rafael Viñoly. 432 Park Avenue, 20 Fenchurch Street ("the Walkie-Talkie", London).
SHoP Architects. 111 West 57th Street (the Steinway Tower).
Jean Nouvel. 53 West 53rd Street.
OMA / Rem Koolhaas. CCTV Headquarters Beijing, De Rotterdam (not strictly supertall but adjacent).
Herzog & de Meuron. 56 Leonard Street NYC.
The structural engineering is dominated by Arup, Buro Happold, Magnusson Klemencic Associates, Thornton Tomasetti, and SOM's in-house structural department. The wind-engineering work is concentrated at three or four specialist consultancies (RWDI in Canada, BMT Fluid Mechanics, the Western University tunnel). The supertall industry is global but its expertise is held by a few hundred professionals.
↑ The Burj Khalifa — engineering marvel of the supertall era
Watch · When Chicago built the tallest building in the world (Sears Tower)
Watch · Empire State Building — the engineering wonder
Carol Willis's Form Follows Finance (1995) for the economic history of the Manhattan/Chicago skyscrapers. Koolhaas's Delirious New York for the cultural-architectural reading. Bascomb's Higher for the Chrysler-Empire State race in narrative detail. The CTBUH database online for current building data. The 2003 Up documentary on the Sears Tower for working-engineering on the Khan tube structure.
The skyscrapers worth visiting in person, in approximate order:
Manhattan. Two days. Empire State Building (rooftop observation), Chrysler Building (lobby tour), Top of the Rock (Rockefeller Center observatory — better view of the Empire State than the Empire State has of itself), One World Trade Center observatory, Edge at Hudson Yards, the SUMMIT One Vanderbilt observatory.
Chicago. Two days. Willis Tower Skydeck (the glass cantilever boxes are corny but compulsory), John Hancock Center observatory, Chicago Architecture Center boat tour (the canonical architectural tourism experience in the United States — covers the Chicago school, the postwar modernist towers, the Khan tube structures, all from the river).
Dubai. Two days. Burj Khalifa observation deck (124th and 148th floors, advance booking essential). The surrounding Dubai Mall and fountain. The Marina district's residential supertalls.
Hong Kong. Two days. The Star Ferry crossing for the canonical Hong Kong skyline view from Tsim Sha Tsui (Kowloon side, looking back at the Central business district). The Sky100 observatory at ICC. The IFC2 mall. The Bank of China Tower lobby.
Shanghai. Two days. Shanghai Tower observation deck (the Sky Lobby at floor 118 is the world's highest observation deck, 562m). Jin Mao Tower. The Shanghai World Financial Center "trapezoid window" observation deck. The Pudong skyline from across the Bund.
Taipei. One day. Taipei 101 Skydeck and the visible tuned mass damper on the 87th-92nd floor.
Kuala Lumpur. One day. Petronas Towers Skybridge (free, advance booking) and observation deck.
Seoul. One day. Lotte World Tower Seoul Sky observatory.
London. One day. The Shard's View from the Shard. 22 Bishopsgate's Horizon 22 (free observation deck added 2023). The Sky Garden at 20 Fenchurch.
Tokyo. One day. Tokyo Skytree observatory (a TV tower, not strictly a skyscraper, but the canonical Tokyo viewpoint at 634m). Tokyo Tower for old-style. The Shinjuku high-rise district from the Tokyo Metropolitan Government Building (free observation).
The 2026–2040 supertall pipeline.
Jeddah Tower (Saudi Arabia, AS+GG). Currently estimated for completion 2028 after extended construction pauses. Planned 1,000m+ — the first kilometre-tall building. The structural design is an extension of the Burj Khalifa buttressed-core system; the foundation construction was substantial.
Dubai Creek Tower (Calatrava). Originally planned to surpass Burj Khalifa; project paused since 2020. Continuing uncertainty about completion.
Tradewinds Square (KL, Malaysia). Two ~700m towers proposed for Kuala Lumpur; long-running planning.
The mass-timber generation. The Mjøstårnet (Brumunddal, Norway, 2019, 85m) and the Ascent Tower (Milwaukee, USA, 2022, 86m) are the current tallest mass-timber buildings. Several proposals for 200–300m mass-timber towers are in pre-design (Tokyo, Vancouver, Stockholm). Whether mass timber can scale to 500m+ is one of the open structural-engineering questions; the wood-fibre fatigue properties under 100 years of wind loading are not yet empirically known at that scale.
The retrofit pipeline. Most major supertall capital expenditure 2025–2040 will be on retrofit of existing buildings — recladding (post-Grenfell), MEP replacement (mid-century systems at end-of-life), envelope upgrades for energy performance. The Empire State Building's $550M retrofit (completed 2010) is the model.
The mixed-use evolution. Pure-office supertalls are being replaced by mixed-use (office, hotel, residential, retail) typologies that balance loads and reduce vacancy risk. The post-2020 work-from-home shift has reduced pure-office demand; mixed-use programming is partly a response.
The smart-building integration. Sensor-driven environmental control, predictive maintenance, occupant-behaviour-driven HVAC. The 2010s and 2020s smart-building wave is making supertalls more energy-efficient through software and continuing to reduce per-occupant energy.
The carbon-net-zero supertall. Various 2020s pilots; difficult to actually achieve. The most-credible claims involve substantial off-site carbon offsets rather than purely architectural reductions.
The honest argument.
For. Skyscrapers concentrate productive economic activity in dense, walkable, transit-served urban cores — the most carbon-efficient form of human settlement we know. A Manhattan resident has roughly half the per-capita carbon emissions of a comparable suburban resident. The skyscraper, embedded in a dense city, is part of the most-sustainable form of large-scale human living.
The architectural achievements of the canonical buildings are real. The Empire State, the Chrysler, the Sears, the Burj Khalifa, the Hancock, the Petronas — these are first-rank works of human engineering. They expanded the working set of what buildings could be.
The technology has cascading civilian benefits. The structural-engineering tools developed for supertalls (wind engineering, seismic design, advanced materials) flow into shorter buildings, bridges, and infrastructure. The skyscraper industry is the technical apex of structural engineering.
Against. The carbon-emissions case is more complicated than the dense-city argument suggests. New supertall construction has high embodied carbon; supertalls operate at higher per-square-metre energy intensity than low-rise; the climate case for new supertalls in 2026 is hard. The sustainability argument better justifies existing supertalls than new ones.
Many supertalls — particularly the residential luxury ones — embody and deepen extreme wealth inequality. The Manhattan pencil towers, the Burj Khalifa upper floors, the Hong Kong residential supertalls. The architecture is in some sense the architecture of capital concentration.
The supertall is an architectural-prestige object, not just a functional building. Many supertalls are partly monuments — to corporations, sovereigns, developers, or cities — rather than economically-rational responses to building demand. The "skyscraper index" pattern (peak completions at peak business cycles, just before crashes) is consistent with this interpretation.
Net. The skyscraper as a typology is one of the great architectural inventions of the 19th and 20th centuries. The post-2010 supertall era has overshot its rational economic basis in many specific cases (China's provincial supertalls; some Manhattan pencil towers; some Gulf trophies) but has also produced canonical works (Burj Khalifa, Shanghai Tower, the Steinway Tower) that will be judged historically as first-rank. The next two decades will test whether the typology can adapt to climate constraints; the canonical buildings of the era are mostly already built.
What to look for, when you stand at the foot of a skyscraper.
The base condition. How does the building meet the ground? Is there a colonnade, a plinth, a setback, a plaza? The base detail tells you the era and the regulatory regime — pre-1916 setbacks, 1916–1961 wedding cake, 1961+ plaza-and-tower.
The structural expression. Can you see the structural columns through the cladding? Are there visible diagonal bracing elements (Hancock, Bank of China)? Are there closely-spaced exterior columns (a tube; the WTC was the canonical demonstration)? Is there a setback every 10–20 floors (likely an outrigger system, the structural gain of an outrigger floor offsetting its programmatic cost)?
The setback strategy. If the building tapers as it rises, why? Pre-1961 zoning required setbacks; modern setbacks are usually wind-engineering (Burj Khalifa's 27 setbacks), structural (capping mechanical floors), or programmatic (smaller upper floors for residential, larger lower floors for office).
The crown. What's at the top? A flat roof (utilitarian; the Sears Tower); a sculpted spire (Empire State, Chrysler); a sharp pinnacle (Pelli's signatures); a tuned mass damper enclosed in a glass crown (Taipei 101); an antenna (One WTC). The crown is where the building announces itself to the city.
The cladding. Glass curtain wall (postwar to 1990s); high-performance double-skin (post-2000); precast concrete panels (often institutional, especially 1960s–1980s); stone (older, premium, mostly pre-1960); metal panels (often signals 1980s postmodernism). The cladding generation usually matches the construction date.
The mechanical floors. Look for blank exterior bands, often with louvres — a mechanical floor housing the building's HVAC for the surrounding 20–40 floors. Most supertalls have mechanical floors every 20–30 floors; their location often coincides with structural setbacks.
The lobby. If you can enter, the lobby tells you what era the building is from and how it conceives of itself. Marble-and-bronze lobbies (1920s–1930s); glass-and-steel openness (1950s–1960s); high-finish premium lobbies (post-2000 luxury commercial). The Seagram Building's lobby is the canonical Mies set-piece; the Burj Khalifa lobby is contemporary luxury at scale.
Three forecasts.
The supertall era continues, at lower volume. The 2020s have seen the global supertall pipeline contract substantially from its 2015–2018 peak. The combination of climate scrutiny, cooling Chinese supertall ambitions, post-COVID office-use shifts, and rising construction costs has slowed new starts. New supertalls will continue to be built — particularly in the Gulf and East Asia — but at perhaps half the 2010s rate.
The retrofit era expands. Most major skyscraper-related construction expenditure 2025–2050 will be on existing-building retrofit rather than new construction. The 1960s–1990s supertall stock requires extensive cladding replacement, HVAC overhaul, and energy-performance upgrade. The Empire State's $550M retrofit is the working model; comparable programmes will be needed at hundreds of major buildings.
Mass timber and embodied carbon. The 2030s and 2040s will probably see substantial mass-timber tall-building activity, replacing some steel-and-concrete construction with lower-carbon alternatives. Whether mass timber can scale to 500m supertalls is unresolved; structural-engineering testing through the late 2020s will be decisive.
The Empire State Building was the world's tallest for 41 years; the WTC for 2 years; the Sears for 25 years; the Petronas for 6 years; the Taipei 101 for 6 years; the Burj Khalifa for 16 years and counting. The era of relatively-stable height records (the Empire State's 41 years) ended with the postwar competition; the era of rapid succession (Sears to Petronas to Taipei to Burj in 25 years) may be ending again.
The skyscraper, as architectural type, is now ~145 years old. It has been continuously evolving — through Sullivan's Chicago, the 1930s Manhattan boom, the postwar curtain wall, Khan's tube, the 2010s supertall, the pencil tower. The next century's evolution will be more constrained by climate, materials, and operational economics than the previous century's was by ambition. The canonical buildings of the era are largely already standing.
From Sullivan's Wainwright (1891) to the Burj Khalifa (2010): 119 years, ~14× height multiplier. Whether the 119 years from 2010 to 2129 will produce a comparable multiplier (and a 12-kilometre tower), some lesser growth, or a flat plateau is the open question.
Skyscrapers — Volume VII, Deck 7 of The Deck Catalog. Set in Trade Gothic with bronze and gold accents on a steel-blue field — corporate-modernist palette as homage to Lever House and Seagram.
Thirty leaves on vertical ambition. From Sullivan's Wainwright (1891) to the Burj Khalifa (2010); from the Chicago school's first 10-storey towers to Manhattan's 24:1 pencil-ratio luxury supertalls. Fazlur Khan's tube structure, the curtain wall, the 1916 zoning, the 9/11 collapses, the Asian shift.
↑ Vol. VII · Arch. · Deck 7