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Griesser provides stylish and sustainable sun shading for the new Blumer Lehmann timber construction / commercial building / Gossau (Switzerland)

The new headquarters of Blumer Lehmann was built in Gossau, eastern Switzerland, over a period of around two years. The Swiss timber construction company, headquartered in Gossau with additional locations in Germany, Austria, and Luxembourg, is one of the leading companies in the timber industry and timber construction.

Innovative timber construction

“The building was designed to welcome and inspire guests and employees alike, and to showcase Blumer Lehmann's expertise – from traditional woodworking to innovative free forms,” says Johanna Deinet, architect and partner at K&L Architekten AG, the architectural firm responsible for the project. The heart of the state-of-the-art timber construction, which is used as an office and reception building, is the atrium with the free-form staircase that gave the “parent company” its name. The design and timber construction technique of the free-form staircase made of curved solid wood panels was developed in collaboration with the ICD Institute for Computer-Based Design and Construction at the University of Stuttgart. It penetrates all five floors of the building and is both a vertical access zone and an identity-creating communication space. The curved atrium surfaces allow views in and out, forming seating niches and balconies that connect the atrium with the surrounding floor levels.

The office building has the floor plan of a single-sided acute-angled quadrangle. It offers space for 180 office workstations on five floors, including event rooms and a cafeteria with a terrace on the ground floor. A spacious foyer and curved atrium staircase welcome visitors. On the second floor, a walkway connects the new building to the neighboring production hall. Additional office space is planned for the upper floor there.

The wood used in the main building comes from the region. Many of the wooden components were also manufactured in Blumer Lehmann's own sawmill.

Well-thought-out sustainable solutions

Sustainable low-tech solutions were used in this unique construction project. The open-plan office spaces are naturally ventilated. Automatic window ventilation at night cools the building in summer. Warm air can escape via the atrium and cold air can flow in via automated window sashes. Clay cooling ceilings in the interior meeting rooms are fed with cold from the ground.

The curtain wall façade gives the building depth and creates a play of shadows. Circumferential balconies with vertical wooden pilaster strips form a multi-layered sun protection level that has a different effect depending on the position of the sun.

Griesser's shading solutions are a central component of the sun protection concept. 112 Soloscreen façade awnings were used in the new building. “The automated, cable-guided facade awnings remain virtually invisible when open. A specially developed metal bracket allows the metal fabric to be attached to the parapet area and the cable guides to be clamped from above, a precise solution with a high degree of design restraint.” Johanna Deinet explains the choice of sun protection and continues: “In connection with the wooden facade with vertically offset lenses, a calm background surface was important to us. In addition, a certain degree of transparency should also be possible when shaded. The slight transparency of the textile awning allows for both.”

Intensive preliminary investigations and tests made it possible to install the Griesser awnings, which would otherwise have been mounted directly on the facade, further forward on the wooden building in Gossau, as Michael Helbling, Regional Manager Projects Eastern Switzerland at Griesser, explains: "Due to the wind resistance class, such an installation would not have been feasible. Thanks to preliminary wind tests carried out on site over a longer period of time, we were able to install our Soloscreen under additional installation conditions without any safety concerns.“ Johanna Deinet adds: ”Despite technical reservations, a conscious decision was made together with the client to opt for a filigree, cable-guided solution. Wind monitors ensure safety by automatically raising the awnings in strong winds."

In addition to the facade awnings, three G2000 patio awnings were also installed in the patio area. To match the Soloscreen, the functional vertical awning was also chosen in the subtle “Charcoal” color, blending harmoniously into the facade.