How tall is the One World Trade Center?

How tall is One World Trade Center?

One World Trade Center stands 541 m (1,776 ft) tall at the top of its spire. CTBUH, the body that keeps the official world rankings of tall buildings, lists the architectural height more precisely as 541.3 m, and the figure in feet is the one most Americans know: 1,776, a deliberate echo of the year the Declaration of Independence was signed. This site uses 541 m as the canonical value.

That single number hides three different measurements, and understanding them explains most of the arguments people have about the tower.

At 541 m, the tower is the tallest building in the United States and in the Western Hemisphere. CTBUH currently ranks it seventh in the world. You can stand it next to any other structure in the 3D height comparison tool.

Spire or antenna? The 2013 ruling that decided the height

CTBUH measures buildings from the lowest significant pedestrian entrance to their "architectural top". Spires count. Antennas, signage, flagpoles and other "functional-technical equipment" do not, because such equipment is frequently added, extended or removed.

One World Trade Center's original design wrapped its rooftop mast in a decorative radome, a sculpted enclosure that clearly made it part of the architecture. During construction the developers dropped the radome for cost and maintenance reasons, leaving an exposed steel lattice that looked a lot like a broadcast antenna. If CTBUH had classed it as an antenna, the building's official height would have fallen to its 417 m roof, below Chicago's Willis Tower at 442.1 m.

On 12 November 2013 the council's height committee ruled that the mast is a spire, an integral and permanent part of the design. That decision confirmed 1,776 ft and made One WTC the tallest building in the Western Hemisphere. Chicago observers had argued the opposite, but the ruling stands, and it remains one of the best-known cases of how definitions shape a skyline record.

Floors: 94, 104 or 110?

Visitors are often confused by the floor count. CTBUH counts 94 actual stories above ground, plus five basement levels. The building's own numbering, however, runs to floor 104, because the numbering skips several double-height mechanical levels. The observatory therefore carries the labels 100, 101 and 102 even though it is not physically the hundredth story.

The number 110 belongs to a different building: the original North and South Towers each had 110 stories. Many people assume the new tower matches, but its floors are taller and fewer, and much of its upper volume is given to mechanical plant rather than offices. According to its published statistics, the tower has 86 usable above-ground floors, of which 78 were planned as office space.

Design and construction

From "Freedom Tower" to One World Trade Center

The building was announced as the Freedom Tower in the master plan for the rebuilt World Trade Center site. In March 2009 the Port Authority of New York and New Jersey, which owns the tower, confirmed One World Trade Center as its official name, describing it as easier for the public and tenants to identify with.

The final design is by David Childs of Skidmore, Owings & Merrill (SOM), the same firm responsible for Willis Tower and Burj Khalifa. WSP was the structural engineer, with Leslie E. Robertson Associates, the original Twin Towers engineers, providing peer review.

The shape

The tower stands on a square footprint 200 ft (61 m) on each side, the same dimensions as each of the original towers. Its edges are chamfered as it rises, so the square base turns into eight tall isosceles triangles and the plan rotates 45 degrees by the top, where a smaller square is crowned by the parapet and spire. Seen from different angles, the building looks like an elongated octahedron and catches light differently on each face.

The lowest 185 ft (56 m) is a windowless reinforced-concrete base, a security measure, clad in glass fins. Above it, the glass curtain wall continues unbroken to the roof.

Timeline

• 27 April 2006 — below-ground construction begins.
• 30 August 2012 — the steel structure tops out.
• 10 May 2013 — the final spire section is lifted into place, bringing the tower to 1,776 ft.
• 12 November 2013 — CTBUH confirms the spire counts toward height.
• 3 November 2014 — the building opens to tenants.
• May 2015 — One World Observatory opens to the public.

Early estimates in 2007 put the cost at about $3 billion; by 2012 the Port Authority's figure had risen to $3.9 billion, making it one of the most expensive office buildings ever constructed.

One World Trade Center versus the original Twin Towers

The comparison most people want is with the buildings the tower replaced. In this site's data, the original Twin Towers stand at 417 m, the roof height of the North Tower (1 WTC), completed in 1972. That is almost exactly the roof height of the new tower, an intentional match. The difference is the spire, which adds about 124 m.

The original North Tower carried a large broadcast antenna that reached well above its roof, but CTBUH never counted it, which is why its official height was the roof figure. You can compare the old and new buildings directly on the Twin Towers page.

How One WTC ranks among the world's tallest

Two entries in that table are not buildings. CTBUH requires that at least 50 percent of a structure's height be occupiable for it to qualify as a building, so telecommunication and observation towers such as the CN Tower and Tokyo Skytree are ranked separately. That is why One WTC is the tallest building in the Western Hemisphere while the CN Tower, about 40 ft taller, remains the tallest freestanding structure on the continent.

Among buildings, the newest challengers to One WTC in the United States are the slender residential towers of Manhattan's Billionaires' Row. Central Park Tower reaches 472.4 m, the highest roof in the Western Hemisphere, but its architectural height is still about 69 m short of One WTC's spire.

Roof height versus spire height: the numbers behind the debate

Because the spire accounts for almost a quarter of the official height, it is worth laying out how One WTC fares under each of CTBUH's three measurements against its nearest American rival, Willis Tower in Chicago.

The table shows why both cities can make a claim. On the measure CTBUH uses for its rankings, One WTC wins comfortably. On tip height, which counts Willis Tower's broadcast antennas, it still wins, but by a much smaller margin. On the height of the highest floor people can actually stand on, and on the flat roof, Chicago's 1973 tower is higher. The Skydeck in Willis Tower, at 412.4 m, is therefore a higher observation deck than One World Observatory, even though the New York building is officially taller.

The 5 m difference between One WTC's architectural top and its tip comes from the beacon and equipment fixed to the top of the spire. CTBUH treats these as functional equipment, which is why the record figure stops at 1,776 ft rather than 1,792 ft.

Where to see the full height from the ground

Close to the base, the tower's tapering form makes it hard to judge how high it goes; the spire almost disappears behind the chamfered edges. The building reads best from a distance, where the full 541 m silhouette can be compared with its neighbors. Popular viewpoints include the waterfront promenades across the Hudson River in Jersey City, Brooklyn Bridge Park on the East River, and the Staten Island Ferry as it approaches Lower Manhattan. From each of these, the spire rises clearly above the surrounding towers of the World Trade Center site, including the other new office buildings on the World Trade Center site.

Visiting One World Observatory

The observatory occupies the top public levels, labeled floors 100 to 102, at 386.5 m (1,268 ft) according to CTBUH. That is higher than the roof of the Empire State Building, whose architectural top is 381 m, so from the observatory you look down on every other skyscraper in Lower Manhattan.

Practical details from the observatory's own site:

• The entrance is at the corner of West and Vesey Streets (117 West Street) on the west side of the World Trade Center site.
• It is open daily, with hours that change seasonally (currently 9:00 to 21:00).
• Dedicated high-speed SkyPod elevators carry visitors from the lobby to the top in under a minute while a time-lapse film of Manhattan's development plays on the cab walls.
• A restaurant, ONE Dine, sits on the same levels and takes reservations.

Putting 541 meters in perspective

A number like 541 m is hard to visualize, so here are some comparisons built from this site's data:

• It is about 3,090 times the height of an average adult man of 175 cm (5′9″).
• Five-and-a-half Statues of Liberty, each 93 m from ground to torch, would stack to roughly the same height.
• It is a little more than 1.6 times the height of the Eiffel Tower at 330 m.
• Burj Khalifa is 1.53 times as tall.

For a broader view, the landmarks hub lists every structure in the catalog, and the height converter will translate any of these meter figures into feet and inches.

Why the number matters

Few buildings carry a height that doubles as a message. Choosing 1,776 ft tied the tower to American founding history, and the CTBUH decision to count the spire protected that symbolism in the record books. Without the spire, One WTC would be a 417 m tower, the same as its predecessor and shorter than several other American buildings. With it, the rebuilt World Trade Center holds the national height record that the North Tower had lost to Chicago's Sears Tower in 1973.