The new administrative building of the Vorarlberg Illwerke was built in six weeks of construction primarily in wood

Outdoor natural, inside nature: the 130-meter-long Illwerke Center Montafon was built by Hermann Kaufmann almost entirely of wood finished parts.
Vandans – Outside the window unfolds with its never-ending coniferous forests and its clammy each other back rocks the rugged landscape of the Montafon. Inside the desk increases at the same time, resinous wood scent in the nose. You already smell the superlatives: The recently completed Illwerke center Montafon, short IZM, with its 10,000 square meters of floor space is currently the largest timber hybrid building in the world. So it’s at least what the client, the Vorarlberg Illwerke AG.

But the really interesting thing about this project is not the size but its construction. For the IZM is the result of a long-term research project emerged from the already the eight-story wooden tower Dornbirner Life Cycle Tower One (LCT One) was completion at the end of 2012. The project team are the Vorarlberg Architect Hermann Kaufmann and the Vorarlberg Contractors Cree, a subsidiary of Rhomberg group.

Proven construction

After the newly developed composite structure made of wood, steel and concrete had proven itself in terms of construction time and cost once already, decided merchant and Cree to use the elaborate LCT- element construction for a second time here. With success: From a total of 14 participants (invited competition) they could claim victory for yourself. A few weeks ago the office building was ready to hand over.

“To be honest, we had no other choice,” said Christoph Dünser, project manager in the office Kaufmann recalls. “Because the building – so it looked the master plan – is about one-third in the pump storage reservoir that serves the power plant operators to generate electricity And after the lake artificially created is almost permanently cultivated, we only had a tiny window of time in which the building over had to leave the stage.”

Specifically: After the foundation and construction of the two stairwell towers were completed, which were carried out due to the fire regulations in concrete, the entire five-story office building was propped in just six weeks into the sky. Then started the interior work, including jobs for 280 employees, cafeteria, training rooms and a visitor center, which is taken annually by around 15,000 visitors to complete.

Building on the block principle

The entire timber was built on a modular principle with serial components. Glued on and integrated in the facade columns are wood-concrete elements, which are held in the center axis of a steel beam. The wooden facade itself is protected to protect against weather and summer overheating by copper clad canopies. Future Bonus: If the area requirement one day grows, so the building can always be increased by a bullet. The necessary static measures have already been taken.

“At these altitudes prefabricated construction is often the only option”, says Dünser. “Conventionally, we would have to build in such a short time can never build». But the construction of the induced GEFORSCHTEN wall and ceiling modules made of wood and steel has another advantage: the Bauungenauigkeit over the entire length of the house is just 15 millimeters. From these figures one can only dream in masonry.

Sustainable project

“The fact that we have chosen for this design, primarily a rational decision was,” says Helmut Mendel, CEO of Vorarlberg Illwerke AG, talking to the standard. «But of course we want to set an example for other companies with this project». The 21- million – euro project (total investment 30 million euros) is in fact a Passive House.

The heating is 14 kWh/m2, the total primary energy demand is at just under 30 kWh/m2. It is heated with the waste heat from the power plant generators; the cooling is done with the water from the adjacent pump storage reservoir. The IZM has been designated as a green building by the U.S. Green Building Council (USGBC). Soon the project will be certified with ÖGNI gold.

Even with the lighting was placed on sustainability value: The overall lighting concept of the IZM is based on LED. The majority of the lamps are connected to daylight sensors and motion detectors. Even the minimalist art installation by Miriam Prant that flickers in the foyer on the ceiling, consists of LED lights. “A building of this nature equip with LED adds to the costs of about 20 percent over conventional lighting,” expects Mennel ago. “We are short more money, so you can save on long-term massively in energy costs”.

Rare: Office building in wood

So far the office buildings in wood and wood composite construction are rarity in Austria. “In the hall, and it is especially true supermarkets, the use of wood as a building material is very constructive widespread”, explains Dieter Lechner by the Association woodworking industry. To date, there are no evaluated numbers. Only this much is certain: “In the residential market share of wooden buildings is already at ten percent since the office buildings are still lagging far behind”, – Said Lechner.