Skyscraper facts worth knowing

The word described a sail before a building

"Skyscraper" was in print for roughly a century before anyone pointed it at architecture. It named the topmost sail on a square-rigged ship, a horse that stood unusually tall, and a high hat of the 1800s. Chicago journalists borrowed it for the office blocks going up downtown in the 1880s, and that meaning pushed the others out. The definition page covers where the 150 m line used today comes from.

The brake, not the elevator, made height usable

Hoists had lifted freight for decades before 1854. Nobody would ride one, because a cab on a snapped rope falls the full shaft. Elisha Otis built a spring-loaded ratchet that bit into notched guide rails the instant rope tension went slack, stood on an open platform at the New York Crystal Palace, and had the rope cut with an axe. He dropped a few inches. Before that, a building stopped at about six stories, the most flights a tenant would climb, and the top floor was its cheapest address. How skyscraper elevators workfollows the machine from there.

The first skyscraper came down in 1931

Chicago's Home Insurance Building, 55 m and 12 floors, went up in 1885 with its walls hung on an iron and steel frame instead of carrying their own weight. It came down in 1931, the year the Empire State Building opened: the building that proved the frame and the one that took the idea to 102 floors overlapped by months. The first-skyscraper page covers the five rivals for the title.

Thirteen months up, forty years on top

Steel for the Empire State Building started rising on 17 March 1930 and the building opened on 1 May 1931: about 13 months for 102 floors, roughly four and a half floors a week, never matched at that height. It then held the world record until 1970, about 40 years, longer than any building before or after it. The Empire State Building pagehas the schedule and the two observatories.

Two spires moved the world record

When the Petronas Twin Towers in Kuala Lumpur took the title from Chicago's Willis Tower in 1998, they did it on decoration. The Chicago tower has more floors, more occupied height and a higher roof, and its antennas reach well past the Malaysian towers. The measuring body, the Council on Vertical Urbanism, counts spires because an architect draws them and excludes antennas because a broadcaster bolts them on, so 452 m beat 442 m by ten meters of sculpted steel. The argument that followed is why most people know a measuring rule exists at all. The Petronas page and the record-by-year list both turn on it.

The Burj Khalifa's top quarter has no rooms

The Burj Khalifa measures 828 m, but its highest occupied floor sits at about 585 m. Everything above that, some 240 m, is spire and mechanical space, an empty stretch taller than the whole Empire State Building. That is why the height people quote and the height anyone stands on are different numbers. The Burj Khalifa page lists both.

Concrete went higher there than anywhere before

Building that tall meant pushing wet concrete up a pipe to 606 m in one stage, further than it had gone before, with the mix adjusted so it would neither set in the line nor separate under pressure. Crews poured at night, because Dubai's heat worked against both. How skyscrapers are builtputs that in the sequence.

A tall building is designed to move

Stiffness enough to hold a tower rigid would cost a fortune and nobody needs it. The common design target is a deflection at the top of about one five-hundredth of the height: roughly 76 cm for the 381 m Empire State Building, well over a meter for the Burj Khalifa. The limit is about comfort. It marks where people inside start to notice, and strength runs out far later. Do skyscrapers sway has the measured figures.

A counterweight with a gift-shop mascot

Taipei 101, 508 m, hangs a 660-tonne sphere of welded steel plate between its 88th and 92nd floors on cables, braked by hydraulic pistons. The ball swings late against the building's own sway and the pistons turn the mismatch into heat. Dampers are ordinary equipment up there; what Taipei 101 did was put the largest one where visitors can look at it, and the gift shop sells Damper Baby, a mascot Sanrio drew from it. The Taipei 101 page has the engineering.

The CN Tower and the Eiffel Tower are not buildings

A building needs continuously habitable floors. The CN Tower has a seven-story pod near the top of a concrete shaft, and the Eiffel Tower has platforms, so neither qualifies however tall it stands. The Eiffel Tower was the tallest thing on earth from 1889 to 1930 and has never made a list of buildings. The Toronto page works through the distinction.

Hong Kong's towers are mostly homes

Hong Kong leads every ranking of tall buildings, with roughly 550 to 570 completed above 150 m, and passes 2,500 if the bar drops to 100 m. New York and Chicago built their skylines out of offices. Hong Kong's boom from the late 1990s went vertical with housing, and estates put 60 to 70 residential floors above a railway station. The Hong Kong page has the land shortage behind it.

China built more than everyone else, then stopped

For most of the two decades after 2003, China finished more tall buildings each year than the rest of the world combined, and it now holds more than 3,000 above 150 m. In April 2020 the Ministry of Housing and Urban-Rural Development told local authorities to stop approving anything above 500 m, and a 2021 order closed the gaps, with officials held accountable for life if they sign off a breach. Skyscrapers in China has the restrictions in full.