Raiffeisen's Upward Sustainability
May 02, 2013
The new Raiffeisen tower, which opened last month on the Donaukanal, is now part of the ever-changing Danube riverscape. The building, shaped like the prow of a ship, points into the gentle curve of the canal, as if about to set sail.
Vienna’s relationship with the Danube (and its meanderings) has a turbulent history. In the beginning of the 16th century, what is now the canal served as the vein of trade and communication to the heart of the evolving city. Today the main river has been restructured and pushed to the outskirts. As Vienna’s appetite for urbanisation fluctuates, so does its relationship to its river.
Monumentally passive
The Raiffeisenhaus Wien Zubau isn’t just a sleek high-rise; it’s the first ultra-low energy ("passive solar") skyscraper in the world.
Designed according to Passivhaus standards, the giant new Raiffeisen building uses several energy collection and conversion systems that work in synthesis to regulate its interior temperature and reduce its energy use.
While a standard passive structure uses only solar energy, Raiffeisen’s system is unique in that it makes use of its proximity to the Donaukanal. The 20,000-square-metre building is cooled using water from the canal, which is pumped through a network of "cold hoses" within the structure’s concrete frame.
Established in 1988 by a team of German and Swiss architects, "passive" design is a process incorporated into a building’s architectural planning. Passive structures are engineered to use ultra-low energy levels – less than 120 kWh per square metre annually, which is half the average yearly energy consumption of traditional office buildings.
A major concern for Vasko & Partner, the energy concept team, was Vienna’s climate. To prevent energy loss during extreme winters, the team patented a "double-façade" design, in which the building is encased in a second layer of glass.
Promoting new energy
In a fitting metaphor, the 21-storey tower is built on the spot formerly occupied by the lower-lying offices of OPEC (The Organisation of Petroleum Exporting Companies). In essence, it replaces "old" energy with "new".
According to Raiffeisen CEO Klaus Buchleitner, the decision to build the new office block according to passive design standards came out of the company’s Klimaschutz (Environmental Protection) Initiative. The measure holds Raiffeisen and its subsidiaries to a common standard of sustainability and socially responsible practices.
"The Passivhaus idea has to do with the identity of Raiffeisen," Buchleitner explained, and it derives from the company’s roots in agricultural banking.
Buchleitner hopes other Austrian companies will follow Raiffeisen’s example in building passive-designed office buildings. "The most important factor in deciding to build according to this standard is ethics," he said, "and how the company thinks about its role in society."