The special feature is not visible from the outside. With its panels, the façade of the high-rise building in Vienna looks rather conventional. "We had to use them for fire protection reasons," says project developer Caroline Palfy.

Text: Vienna / By Matthias Röder, dpa 

The real gimmick of the 84-meter-high building, into which the first commercial tenants will move in the fall: From the second floor upwards, 75 percent of it is made of wood. Around 800 wooden columns made from Austrian spruce support the floors, the wall elements are made from this renewable raw material, as is the wooden composite ceiling.

With an area of almost 20,000 square meters, it is a timber-reinforced concrete hybrid building that is unparalleled in this dimension, according to Palfy. "It is a statement for the use of wood in high-rise construction," says the 40-year-old, who is a master builder and engineer.

The concern that a high-rise building made primarily of wood could become a fire trap is unfounded, emphasizes Palfy. "A material that is flammable doesn't have to have bad properties in the event of a fire." The 40 x 40 and even 40 x 124 centimeter thick wooden columns are extremely robust. In addition, a wall/ceiling element was exposed to 1000 degrees in a combustion chamber for 90 minutes. The result: only the outer 8.4 centimetres of the tested elements were charred and the material was still load-bearing. Statically, every second column could fail and the building would still stand, says Palfy. "We are not the biggest matchbox in the world, as critics once said."

"Conventional is bland", she thought when she acquired the land in 2013, says Palfy. Investor Günter Kerbler did not hesitate when it came to the timber high-rise called "Hoho Wien". Even if the project turned out to be somewhat more expensive than a conventional reinforced concrete building due to its own pioneering work. A total of around 75 million euros was invested in the 24-storey main building and the five-storey annexe. The hotel, office and restaurant areas account for 70 percent of the total.

Hoho Wien" is located in one of Vienna's showcase areas. In Seestadt in the north-east of the Austrian capital, one of Europe's largest urban development projects has been taking shape in recent years. By 2028, affordable housing for 20,000 people and jobs for many thousands of people are to be created here on 240 hectares.

The arguments for prospective customers are the good indoor climate and, of course, the reference to the environmental balance. "The wood we use is regrown in Austrian forests in one hour and 17 minutes," Palfy calculates. To her regret, however, it is not yet possible to do without air conditioning in commercially used rooms. "That would not be marketable."

Text: Vienna / By Matthias Röder, dpa 

Architecture: Rüdiger Lainer

Photos: Michael Baumgartner | KiTO | www.kito.at

More photos under Portfolio HoHo Vienna