The award ceremony took place at NEST, the research and innovation building of Empa and Eawag. The winner is a project from Darmstadt – the renovation of the unique exhibition building on the Mathildenhöhe, which has been a UNESCO World Heritage Site since 2021. It will be realized by the architecture firm schneider+schumacher. “We were extremely impressed by how this historic building is being modernized in terms of energy, with the help of aerogel, among other things. From our point of view, this is the first time that such a large building is being renovated in this way,” summarizes jury member Matthias Koebel, former head of Empa’s Building Energy Materials and Components lab and now CEO of the Empa spin-off Siloxene AG, the jury discussion.
Future-proofing world heritage
Initially, the reason for the renovation was the outdated building technology. It quickly became clear, however, that an overall concept was needed to make the exhibition building energetically fit. Therefore, a comprehensive, sustainable energy concept was developed in cooperation with the German Federal Environmental Foundation. In addition to modern glazing that allows the controlled use of daylight, a new type of high-performance mineral-based insulating plaster made of aerogel granules is used in the building envelope. This will significantly improve the energy efficiency. In future, the conditions on site will also be brought to a far better use, for instance, by using the historic water reservoir underneath the exhibition building to store energy.
Improving energy efficiency step by step
The second place went to the parish center Heilig Geist in Zurich. It includes a church, community rooms, offices and apartments and was opened in 1973. The fact that little attention was paid to building insulation at that time can be seen in the parish’s high energy consumption. Over the years, architect Beat Kämpfen of Kämpfen Zinke + Partner thus implemented various measures to optimize the building’s energy efficiency. These included several solar systems on the entire area, the use of aerogel in the façade, and the replacement of the gas heating system with a heat pump system including geothermal probes. It was always important that the external appearance of the parish remains more or less unchanged. Thanks to the innovations, the center received the Minergie certification in 2020. “What stood out for us was the holistic approach, with which the center was renovated and optimized in terms of energy,” says Koebel.
Preserving the appearance
The third place on the podium went to a building in Winterthur. The building, Haus am Lindberg, was built in 1963 and purposefully developed over the years without changing the basic structure. This requirement also applied to the renovation of the building envelope, which was done by an architect’s team led by Anne-Kathrin Halt. This meant that, among other things, the volume of the building could not be changed and various elements, such as a ceramic relief on the wall, had to be preserved. Therefore, they decided to insulate the villa using aerogel panels. For this purpose, the existing roughcast including the base plaster was first removed down to the masonry. The exposed volume was filled with 20 mm thick aerogel panels, the roughcast was reapplied and the original exposed concrete structure was reconstructed. “We were very impressed with the application of aerogel in this challenging façade and the enormous area where the material was used,” says juror Michael O’Connor.
The Aerogel Architecture Award
The Aerogel Architecture Award was initiated in 2020 by Empa and the industry partners Fixit, Agitec, Haga AG Naturbaustoffe, Hasit and the AdvaPor association. For the 2022 competition, eight participants from Germany, China and Switzerland had submitted projects. A jury consisting of five experts – Matthias Koebel (Switzerland), Ralf Kilian (Germany), Michael O’Connor (France), Volker Herzog (Germany) and Manfred Wehdorn (Austria) – evaluated the submitted projects with regard to their conservation value, energy efficiency and the originality of the chosen solution. Further information on all submitted projects can be found here: https://www.empa.ch/web/aaa/results
