A wooden building that rises steadily... Highest record at over 86 meters
|Ascent, the world's tallest wooden building with 25 stories above the ground and 86 meters in height, is located in Milwaukee, USA. Korb & Associates Architects|
The record for the tallest wooden building in the world has been broken.
The World Association of Skyscrapers and Urban Architects (CTBUH) announced that the 25-story residential and commercial complex Ascent in Milwaukee, USA, completed in July, has been certified as the world's tallest wooden building.
The building is 86.6 m high, 1.2 m higher than the 18-story Miestorone (85.4 m high) in Oslo, Norway, completed in March 2019 . It is a wood-concrete hybrid building with laminated timber (GLT) beams, columns, and cross laminated timber (CLT) floors stacked on top of a concrete lower floor. In the center of the building, two concrete cores serve as the backbones that support the entire building.
Of the total 25 floors, 5 above ground level with shops and parking lots are concrete structures. The 6th floor is a swimming pool, and the 19th floors above it are 259 apartments.
If the core frame of a structure such as main column and horizontal beam is made of wood, the skyscraper is recognized as a wooden building even if other materials are used.
Three advantages of wooden buildings
The building, designed by Korb + Associates Architects, was completed just two years after construction began in August 2020.
According to the architect, the building has three advantages. The first is to isolate the carbon emitted by 2,400 cars annually through wood, the second is to shorten the construction period by 3-4 months, and the third is to realize the beauty of wood in modern urban architecture.
“Usually, when wood is used for structural systems, the construction period is reduced by about 25% compared to conventional concrete buildings of the same size,” the Association of High-Rise Urban Architects said. In the case of Ascent, the construction period was shortened by prefabricating wooden beams, columns and walls and then assembling them on site.
100-meter wooden building to appear in 2026
Following Ascent, a wooden structure over 100 meters in height is expected to appear in 2026. It is a 100-meter-tall mixed-use wooden building to be built near Zurich, Switzerland. The building project, dubbed Rocket&Tigerli, will be the first wooden building to open the 100-meter era when completed in 2026 as scheduled.
In Berlin, Germany, plans to build a 98-meter-high residential complex hybrid wooden building were announced in Lausanne, Switzerland. The target completion date for both buildings is 2026.
Passed the world's first 3-hour fire test
This high-rise wooden building is possible thanks to laminated timber manufacturing technology, which is stacked alternately and then compressed. Also called the concrete of the future, this wood weighs significantly less than concrete, but is as strong as concrete and resistant to fire. It is thick and hard by attaching several layers of wood, and the outer surface is coated with heat resistance, so it does not spread easily even in a fire. Ascent's structural engineering company, Thornton Tomasetti, said, "The laminate used in Ascent has passed a three-hour fire test for the first time in the world."
The laminated wood building is also more advantageous than concrete in controlling humidity and is strong against earthquakes. Wood joints compensate for vibrations caused by earthquakes. There is also the advantage of reducing the construction cost and period as it can be assembled immediately by bringing wood processed to the standard without waiting for the concrete to harden. The eco-friendliness and psychological intimacy of a natural material called wood cannot be left out.
Dr. Se-jong Kim (wood engineering) at the National Academy of Forest Sciences said, “The market conditions such as material supply and demand and price are the limiting factors for wooden high-rise construction rather than technical problems.”