Future trend: soaring high with wood

"Hoho" in Vienna (© cetus Baudevelopment GmbH)

For many years, wood has been experiencing a renaissance as a material for homes and other buildings. Today, prefabricated houses are mainly made from wood or wood-composite materials. And the eternally young material is again seeing increasing use in industrial buildings or supporting structures for roofs and bridges.


Looking to expand the use of wood, construction physicists and wood processors discovered multistory commercial buildings some time ago. Today, a sophisticated system design, intelligent structural solutions and hybrid construction elements using more than 70 % wood allow multistory buildings to be made of wood. For example, an eight-story office building with a height of 27 m was constructed of wood four years ago in Vorarlberg, Austria. It complies with the passive house standard and is known as the Life Cycle Tower. The components were prefabricated so that the building only took a few days to be erected. In other countries, for example Norway, wooden skyscrapers with 10 and more floors have also been built.


However, the tallest wooden building in the world stands shortly before completion in the Aspern district of Vienna: the HoHo, an office building with a height of 84 m and 24 floors consisting to 75 % of wood - a genuine construction challenge.


Designs of this kind are made possible by the use of cross-laminated timber (CLT), among other things. This involves bonding lamellas stacked crosswise under high pressure to form large-sized solid wood elements. Cross-lamination significantly reduces swelling and shrinkage, as well as substantially improving the structural load-bearing capability and form stability.