Second building block Attisholz site
Vision 2045 for the Attisholz site in Riedholz sets out clear objectives. “A generational project and role model for sustainable living space development” is to be created on the site of the former cellulose factory. Following this claim with seriousness, owner Halter AG organized another competition for the conversion of the existing building after the study contract Kocherei. The work group procedure “Building Warehouse” aimed in an exemplary manner at the preservation of the architectural heritage and its future-oriented further development. With its position as a “prelude” to the site and its direct references to the Aare region, the Warehouse has a special status. The organizer was looking for coherent and sustainable concepts for the separate tasks of “supporting structure” and “building envelope”.
The team Anliker AG / Alpiger Holzbau AG / Lüchinger+Meyer, whose submission was limited to this specialist area, was able to secure the competition success in the “Supporting structure” group of works. The jury explained its decision as follows: There is “a very strong focus on the task at hand, and the mindset is characterized by the commitment to ‘reduce to the maximum.’ This results in a well-rounded proposal that is easy to implement. Thus, the innovative character lies mainly in the simplicity, the strong solution orientation and the flexibility in combination with the building envelopes of all other groups of works. Also, the engineering is convincing. The proposed slender concrete structures reduce the use of materials and construction materials and achieve high flexibility in case of reuse, giving the structures a very high durability. Construction site and city logistics are optimized, and local resources are utilized. The collaboration is characterized by an interdisciplinary mentality and teamwork.”
Variant studies were carried out by the Lüchinger+Meyer engineers involved for the planned additions to the existing building. For the west and middle additions, a hybrid solution with wood-concrete composite ceilings with cross-laminated timber (CLT ceilings), as well as a purely conventional solution with material-saving, slim 20cm flat ceilings in reinforced concrete were presented in each case. “The careful evaluation of possible load-bearing systems was particularly appreciated by the judging panel and probably ultimately also led the way for the overall most convincing structural system of all the competition entries.” Both structural variants proved to be competitive in the sustainability analysis. Measures such as the use of CO2-reduced concrete, concrete recycling material to conserve natural gravel resources, additional sequestration and the establishment of short material transport distances further minimize CO2 emissions.
“The in-depth examination of the building condition is also particularly commendable. The group of works paid great attention to the construction process and the structural measures required for realization. Excavation pit closures, foundation concepts and deconstruction measures were already projected with considerable depth, so that the technical considerations could be comprehended by the assessment committee and the performance specification could be checked for plausibility.”
We are looking forward to the realization of the project with our partners and in cooperation with the winner of the work group “Facade” Blumer Lehmann.
(Photo: Halter AG, Schlieren)
