Welcome to the I Can't Sleep Podcast,
Where I help you drift off one fact at a time.
I'm your host Benjamin Boster,
And today's episode is about skyscrapers.
A skyscraper is a very tall building,
Or otherwise permanently habitable structure.
Typically defined as reaching a minimum height of either 100 meters or 150 meters in height.
However,
There remains no universally accepted definition of a skyscraper,
Other than being a high-rise.
Skyscrapers can host a variety of spaces,
Typically including office,
Commercial,
Hotel,
And residential space.
Skyscrapers are a common feature in the downtown or central business districts of major cities,
Especially in the Americas,
Asia,
And Australia,
Often due to a high demand for space and limited availability of land.
Majority of skyscrapers are designed with a steel frame and sheer walls that support curtain walls.
These curtain walls either bear on the framework below,
Or are suspended from the framework above,
Rather than resting on load-bearing walls of conventional construction.
Some early skyscrapers have a steel frame that enables the construction of load-bearing walls taller than those made of reinforced concrete.
Modern skyscraper walls are not load-bearing and are characterized by large surface areas of windows made possible by steel frames and curtain walls.
However,
Skyscrapers can have curtain walls that mimic conventional walls with a small surface area of windows.
Modern skyscrapers often have a tubular structure and are designed to act like a hollow cylinder to resist wind,
Seismic and other lateral loads.
To appear more slender,
Allow less wind exposure,
And transmit more daylight to the ground,
Many skyscrapers are built with setbacks,
Which in some cases is also structurally required.
Skyscrapers first appeared in the United States at the end of the 19th century,
Especially in the cities of Chicago and New York City.
Following a building boom across the Western world in the early 20th century,
Skyscraper development was halted in the 1930s by the Great Depression,
And did not resume until the 1950s.
A skyscraper boom in the downtowns of many American cities took place during the 1960s to 1980s.
Towards the second half of the 20th century,
Skyscrapers began to be built more frequently outside the United States.
Particularly in East Asia and Southeast Asia during the 1990s.
China has since overtaken the United States as the country with the most skyscrapers.
Skyscrapers are an increasingly global phenomenon and can be found in at least 70 countries.
There are over 7,
000 skyscrapers over 150 meters in height worldwide,
Most of which were built in the 21st century.
Over three quarters of skyscrapers taller than 150 meters are located in Asia.
20 cities in the world have at least 100 skyscrapers that are taller than 150 meters.
Most recently Singapore,
Hangzhou,
Moscow,
And Toronto in 2025.
The city with the most skyscrapers in the world is Hong Kong,
With a total of 569 skyscrapers,
Followed by Shenzhen,
China,
With 465,
New York City in the United States with 324,
And Dubai,
United Arab Emirates,
With 269.
The tallest skyscraper in the world is the Burj Khalifa in Dubai with a height of 828 meters.
The term skyscraper was first applied to buildings of steel-framed construction of at least 10 stories in the late 19th century.
A result of public amazement at the tall buildings being built in major American cities like New York City,
Philadelphia,
Boston,
Chicago,
Detroit,
And St.
Louis.
The first steel-framed skyscraper was the Home Insurance Building,
Originally 10 stories,
With a height of 42 meters,
Or 138 feet,
In Chicago in 1885.
Two additional stories were added.
Some point to Philadelphia's ten-story Jane Building as a proto-skyscraper,
Or to New York's seven-floor Equitable Life Building,
Built in 1870.
Steel skeleton construction has allowed for today's super tall skyscrapers now being built worldwide.
The nomination of one structure versus another,
Being the first skyscraper,
And why,
Depends on what factors are stressed.
The structural definition of the word skyscraper was refined later by architectural historians based on engineering developments of the 1880s that had enabled construction of tall multi-story buildings.
The definition was based on the steel skeleton,
As opposed to the construction of load-bearing masonry,
Which passed their practical limit in 1891 with Chicago's Panadnock building.
What is the chief characteristic of the tall office building?
It is lofty.
It must be tall.
The force and power of altitude must be in it.
The glory and pride of exaltation must be in it.
It must be every inch a proud and soaring thing,
Rising in sheer exaltation that from bottom to top it is a unit without a single descending line.
Louis Sullivan's The Tall Office Building Artistically Considered,
1896.
Some structural engineers define a high rise as any vertical construction for which wind is a more significant load factor than earthquake or weight.
Note that this criterion fits not only high-rises,
But some other tall structures such as towers.
Different organizations from the United States and Europe define skyscrapers as buildings at least 150 meters in height or taller.
With super tall skyscrapers for buildings higher than 300 meters and mega tall skyscrapers for those taller than 600 meters.
The tallest structure in ancient times was the 146-meter Great Pyramid of Giza in ancient Egypt,
Built in the 26th century BC.
It was not surpassed in height for thousands of years.
The 160-meter Lincoln Cathedral having exceeded it in 1311 to 1549 before its central spire collapsed.
The ladder in turn was not surpassed until the 555-foot Washington Monument in 1884,
Which was surpassed by the Eiffel Tower in 1889,
The first ever super-tall structure.
However,
Being uninhabited,
None of these structures actually comply with a modern definition of a skyscraper.
In 1930,
The Chrysler Building surpassed the Eiffel Tower by a pinnacle hide,
Becoming the tallest structure built until then,
And the first super-tall skyscraper by a pinnacle hide,
Only to be surpassed a year later,
In every regard,
By the Empire State Building,
As the first super-tall skyscraper also by a roof hide.
High-rise apartments flourished in classical antiquity.
Ancient Roman insulae and imperial cities reached ten and more stories.
Beginning with Augustus,
Several emperors attempted to establish limits of 20 to 25 meters per multi-stories buildings.
But where met was only a limited success.
Lower floors were typically occupied by shops or wealthy families,
With the upper rented to the lower classes.
Surviving Oxyrhynchus papyri indicate that seven stories buildings existed in provincial towns,
Such as in 3rd century AD Hermopolis in Roman Egypt.
The skylines of many important medieval cities had large numbers of high-rise urban towers,
Built by the wealthy for defense and status.
The residential towers of 12th-century Bologna numbered between 80 and 100 at a time,
The tallest of which is the 97.
2-meter-high Azzanelli Tower.
A Florentine law of 1251 decreed that all urban buildings be immediately reduced to less than 26 meters.
Even medium-sized towns of the era are known to have proliferations of towers,
Such as the 72 towers that ranged up to 51 meters in height in San Gimignano.
The medieval Egyptian city of Fustat housed many high-rise residential buildings,
Which al-Muqaddasi in the 10th century described as resembling minarets.
Nazir Khuzra,
In the early 11th century,
Describes some of them rising up to 14 stories,
With roof gardens on the top floor,
Complete with ox-drawn water wheels for irrigating them.
Cairo in the 16th century had high-rise apartment buildings where the two lower floors were for commercial and storage purposes,
And the multiple stories above them were rented out to tenants.
An early example of a city consisting entirely of high-rise housing is the 16th century city of Shebom in Yemen.
Shibum was made up of over 500 tower houses,
Each one rising 5 to 11 stories high,
With each floor being an apartment occupied by a single family.
The city was built in this way in order to protect it from Bedouin attacks.
Shebom still has the tallest mud brick buildings in the world,
With many of them over 30 meters high.
An early modern example of high-rise housing was in the 17th century Edinburgh,
Scotland,
Where a defensive city wall defined the boundaries of the city.
Due to the restricted land area available for development,
The houses increased in height instead.
Buildings of 11 stories were common,
And there are records of buildings as high as 14 stories.
Many of the stone-built structures can still be seen today in the Old Town of Edinburgh.
The oldest iron-framed building in the world,
Although only partially iron-framed,
Is the Flax Mill in Shrewsbury,
England.
Built in 1797,
It is seen as the grandfather of skyscrapers,
Since its fireproof combination of cast iron columns and cast iron beams developed into the modern steel frame that made modern skyscrapers possible.
In 2013,
Funding was confirmed to convert the derelict building into offices.
In 1857,
Elisha Otis introduced the safety elevator at the E.
V.
Howatt Building in New York City,
Allowing convenient and safe transport for buildings' upper floors.
Otis later introduced the first commercial passenger elevators to the Equitable Life Building in 1870.
Considered by some architectural historians to be the first skyscraper.
Another crucial development was the use of a steel frame instead of stone or brick.
Otherwise the walls on the lower floors on a tall building would be too thick to be practical.
An early development in this area was Oriel Chambers in Liverpool,
England,
Built in 1864.
It was only five floors high.
The Royal Academy of Arts states,
Critics at the time were horrified by its large agglomerations of protruding plate glass bubbles.
In fact,
It was a precursor to modernist architecture,
Being the first building in the world to feature a metal-framed glass curtain wall,
A design element which creates light airy interiors,
And has since been used the world over as a defining feature of skyscrapers.
Further developments led to what many individuals and organizations consider the world's first skyscraper,
The 10-story Home Insurance Building in Chicago,
Built from 1884 to 1885.
While its original height of 42.
1 meters does not qualify as a skyscraper today,
It was record-setting for the day.
The building of tall buildings in the 1880s gave the skyscraper its first architectural movement,
Broadly termed the Chicago School,
Which developed what has been called the commercial style.
The architect,
Major William LeBaron Jenney,
Created a load-bearing structural frame.
In this building,
A steel frame supported the entire weight of the walls,
Instead of load-bearing walls carrying the weight of the building.
This was then draped with a stone curtain for aesthetic purposes.
This development led to the Chicago Skeleton form of construction.
In addition to the steel frame,
The Home Insurance Building also utilized fireproofing,
Elevators,
And electrical wiring,
Key elements in most skyscrapers today.
Burnham & Rootes,
45 meters,
Rand McNally Building in Chicago,
1889,
Was the first all-steel-framed skyscraper,
While Louis Sullivan's 41-meter Wainwright Building in St.
Louis,
Missouri,
1891,
Was the first steel-framed building with soaring vertical bands to emphasize the height of the building,
And is therefore considered to be the first early skyscraper.
In 1889,
The Mole Antonelliana in Italy was 179 meters tall.
Most early skyscrapers emerged in the land-strapped areas of New York City and Chicago toward the end of the 19th century.
A land boom in Melbourne,
Australia between 1888 and 1891 spurred the creation of a significant number of early skyscrapers,
Though none of these were steel-reinforced,
And few remain today.
Height limits and fire restrictions were later introduced.
In the late 1800s,
London builders found building heights limited due to issues with existing buildings.
High-rise development in London is restricted at certain sites if it would obstruct protected views of St Paul's Cathedral and other historic buildings.
This policy,
St.
Paul's Heights,
Has officially been in operation since 1927.
Concerns about aesthetics and fire safety had likewise hampered the development of skyscrapers across continental Europe for the first half of the 20th century.
By 1940 there were around 100 high-rise buildings in Europe.
Some of these examples are the 43-major-tall 1898 White House in Rotterdam.
The 51.
5-meter-tall PASST building in Warsaw,
The Royal Liver Building in Liverpool,
Completed in 1911 and 90 meters high,
The 57 meter tall 1924 Marx House in Dusseldorf The 65 meter tall Borschturm in Berlin,
Built in 1924,
The 65 meter tall Hansa-Hochhaus in Cologne,
Germany,
Built in 1925.
The 61-meter Kungstornen in Stockholm,
Sweden,
Which were built 1924-25,
The 77 meter Ulsteinhaus in Berlin,
Germany,
Built in 1927,
The 89-meter Edificio Telefónica in Madrid,
Spain,
Built in 1929.
The 87.
5-meter Burrentoren in Antwerp,
Belgium,
Built in 1932,
The 66-meter Prudential Building in Warsaw,
Poland,
Built in 1934.
And the 108-meter Torre Piacentini in Genoa,
Italy,
Built in 1940.
After an early competition between New York City and Chicago for the world's tallest building,
New York took the lead by 1895 with the completion of the 103-meter tall American Surety Building,
Leaving New York with the title of the world's tallest building for many years.
America by far produced the most skyscrapers in this period.
Modern skyscrapers are built with steel or reinforced concrete frameworks and curtain walls of glass or polished stone.
They use mechanical equipment such as water pumps and elevators.
Since the 1960s,
According to the CTBUH,
Council on Tall Buildings and Urban Habitat,
The skyscraper has been reoriented away from a symbol for North American corporate power,
To instead communicate a city or nation's place in the world.
The construction of very tall skyscrapers entered a three decades long era of stagnation in 1930 due to the Great Depression and then World War II.
Shortly after the war ended,
Russia began construction on a series of skyscrapers in Moscow.
Seven,
Dubbed the Seven Sisters,
Were built between 1947 and 1953.
And one,
The main building of Moscow State University,
Was the tallest building in Europe for nearly four decades.
Other skyscrapers in the style of socialist classicism were erected in East Germany,
Poland,
Ukraine,
Latvia,
And other Eastern Bloc countries.
Western European countries also began to permit tall skyscrapers during the years immediately following World War II.
Early examples include Edificio España,
In Spain,
And Torre Brera,
Italy.
From the 1930s onward,
Skyscrapers began to appear in various cities in East and Southeast Asia,
As well as in Latin America.
Finally,
They also began to be constructed in cities in Africa,
The Middle East,
South Asia,
And Oceania in the late 1950s.
Skyscraper projects after World War II typically rejected the classical designs of the early skyscrapers,
Instead embracing a uniform international style.
Many older skyscrapers were redesigned to suit contemporary tastes or even demolished,
Such as New York's Singer Building,
Once the world's tallest skyscraper.
German-American architect Ludwig Mies van der Rohe became one of the world's most renowned architects in the second half of the 20th century.
He conceived the glass façade skyscraper,
And along with Norwegian Fred Sevrud,
Designed the Seagram building in 1958,
A skyscraper that is often regarded as the pinnacle of modernist high-rise architecture.
Skyscraper construction surged throughout the 1960s.
The impetus behind the upswing was a series of transformative innovations which made it possible for people to live and work in cities in the sky.
In the early 1960s,
Bangladeshi-American structural engineer Fazlur Rahman Khan,
Considered the father of tubular designs for high-rises,
Discovered that the dominating rigid steel frame structure was not the only system apt for tall buildings,
Marking a new era of skyscraper construction in terms of multiple structural systems.
His central innovation in skyscraper design and construction was the concept of the tube structural system,
Including the frame tube,
Truss tube,
And bundled tube.
His tube concept,
Using all the exterior wall parameter structure of a building to simulate a thin-walled tube,
Revolutionized tall building design.
These systems allowed greater economic efficiency,
And also allowed skyscrapers to take on various shapes,
No longer needing to be rectangular and box-shaped.
The first building to employ the tube structure was the Chestnut DeWitt apartment building,
Considered to be a major development in modern architecture.
These new designs open an economic door for contractors,
Engineers,
Architects,
And investors,
Providing vast amounts of real estate space on minimal plots of land.
Over the next 15 years,
Many towers were built by Fazlur Rahman Khan and the Second Chicago School,
Including the 100-story John Hancock Center and the massive 442-meter Willis Tower.
Many buildings designed in the 1970s lacked a particular style and recalled ornamentation from earlier buildings designed before the 1950s.
These design plans ignored the environment and loaded structures with decorative elements and extravagant finishes.
This approach to design was opposed by Fazlur Khan,
And he considered the designs to be whimsical rather than rational.
Moreover,
He considered the work to be a waste of precious natural resources.
Kahn's work promoted structures integrated with architecture and the least use of material resulting in the smallest impact on the environment.
The next era of skyscrapers will focus on the environment,
Including performance of structures,
Types of material,
Construction practices,
Absolute minimal use of materials and natural resources,
Embodied energy within the structures,
And more importantly,
A holistically integrated building systems approach.
Modern building practices regarding super tall structures have led to the study of vanity height.
Vanity Hide,
According to the CTBUH,
Is the distance between the highest floor and its architectural top,
Excluding the antennae,
Flagpole,
Or other functional extensions.
Vanity Hyde first appeared in New York City skyscrapers as early as the 1920s and 1930s.
But super-tall buildings have relied on such uninhabitable extensions for,
On average,
30% of their height,
Raising potential definitional and sustainability issues.
The current era of skyscrapers focuses on sustainability,
Its build and natural environments,
Including the performance of structures,
Types of materials,
Construction practices,
Absolute minimal use of materials,
And natural resources,
Energy within the structure,
And a holistically integrated building system approach.
LEED is a current green building standard.
Architecturally,
With the movements of postmodernism,
New urbanism,
And new classical architecture that established since the 1980s a more classical approach came back to global skyscraper design that remains popular today.
Other contemporary styles and movements in skyscraper design include organic,
Sustainable,
Neo-futurist,
Structuralist,
High-tech,
Deconstructivist,
Blob,
Digital,
Streamline,
Novelty,
Critical regionalist,
Vernacular,
Neo-art deco,
And neo-historist,
Also known as revivalist.
September 3rd is the global commemorative day for skyscrapers called Skyscraper Day.
