Korina Gutsche: "I knocked on many doors"
What does the green film of the future look like? ...
Looking at the city and shaping the future with wood: Architect Eike Roswag-Klinge has been working on this for years. He is head and co-founder of the architecture and engineering firm ZRS, which focuses on sustainable construction and initiates projects all over the world. He is also professor of Architecture at the TU Berlin and this year part of the festival MAKECITY. We talked to him about the future of the construction industry and asked what role natural building materials could play as sustainable resources for a city like Berlin.
CCB Magazine: Eike, you will soon be a speaker at this year's Make City and talk about a repositioning of urban timber construction. What is that about?
Eike Roswag-Klinge: My main focus will be on the use of wood in an urban context. This specifically refers to the redensification of buildings, the addition of storeys through wooden constructions, the energetic optimization through various façade systems and partly also new buildings. Everything made of wood and other natural building materials.
CCB Magazine: Since the 1990s, alternative building communities have developed in cities such as Freiburg, Hamburg, Tübingen and Berlin, which have experimented with climate-neutral and resource-saving wooden buildings. However, these were mostly academics with a high level of education who could afford to do so. Is wood also suitable for the construction of social housing?
Eike Roswag-Klinge: We have not yet reached that point. As we unfortunately still only consider the investment costs and not the costs over the entire life cycle of houses, this is still difficult at the moment. But what we have already achieved is hybrid construction, i.e. the increased mixture of concrete, steel, wood and other building materials. The housing associations, which have to pay very close attention to price, are increasingly building wooden facades, for example, because this is cheaper than conventional, highly insulated building shells. Especially wooden extensions are in vogue because they are much lighter than those made of reinforced concrete. There is a big market there. The housing association Wohnungsbaugesellschaft Mitte, for example, wants to add storeys to prefabricated buildings from the 1960s, 70s and 80s with wooden constructions with up to three storeys. This is only possible with wood, everything else would be too heavy, as I said. Berlin is a pioneer in this respect. In the future, building systems will become simpler and cheaper, which will lead to an increase in wooden buildings in urban areas.
CCB Magazine: What added value does building with wood offer for climate protection compared to building with steel and concrete?
Eike Roswag-Klinge:With natural building materials such as wood or clay we do not consume fossil resources, wood also stores CO2. By contrast, we use a great deal of energy in the production of concrete, cement and above all steel, which accounts for a large part of the ecological footprint in the construction sector. The production of reinforced concrete and steel alone can generate between 30 and 50% of a building's resource consumption. At the moment, foundations made of steel and concrete are still needed, but alternatives are already being worked on and researched to replace them or at least greatly reduce their use as building materials.
Germany has great competence in loam and timber construction. Together with bamboo, these are the natural building materials that will lead to global change in the construction industry
CCB Magazine: Doesn't the increased use of wood for construction pose the risk of overuse of forests? This already happened in the 19th century: even forest areas such as the Black Forest were largely cut down.
Eike Roswag-Klinge: The concept of sustainability was coined precisely by the experience of mass deforestation in Europe. In 1713, the Electoral Saxon mountain ruler Hans Carl von Carlowitz coined the term sustainable forestry, on the basis of which forests in many European countries are still managed in a careful and farsighted manner today. In Germany and some other European countries, all buildings could be built and converted from German wood without any problems today. In the global context, of course, things are different. We need massive reforestation of forest stands to compensate for past clear-cutting.
CCB Magazine: What do you actually think about the idea of a right to green spaces in the German constitution?
Eike Roswag-Klinge:First of all, I would establish a basic right to affordable housing. Of course we also demand a densification and activation of green spaces, especially in the big cities. There is no point in shorn grass stretching between the rows of houses in our 1950s buildings; that's where trees should go, kitchen gardens, sports fields, and such spaces between and beside buildings can be used more effectively and greener.
CCB Magazine: If one thinks of sustainability in construction, many factors must interlock, ecology, economy and social justice. How are these factors interrelated? Isn't urban timber construction ultimately only for people with money in their pockets?
Eike Roswag-Klinge: I believe that this will change very quickly if we start to combat the consequences of our fossil fuel consumption more rigorously, for example by introducing a CO2 or resource tax that prices the ecological consequences of our consumer society. This would also affect the concrete and cement industry, among others. In addition, subsidies for lignite should be reduced and the money should instead be invested in expanding renewable energies in order to promote the energy turnaround. Although timber buildings are still more expensive to build than conventional buildings, they are generally cheaper in their life cycle over 50 years. Politicians should take this into account in legislation and create additional economic incentives. As far as the latter is concerned, however, we are as much in the Stone Age as we are with mobility. Society as a whole is much more willing to embrace change than politicians would like to admit. The real resistance comes from the business community: Why should I change my successful model - diesel passenger car, concrete house - when it is running? Things are moving very slowly. However there are also large building contractors such as Züblin, who are currently buying massive timber construction because they realize that there is a trend reversal in the construction industry. If we want to prevent climate change, we need a different attitude when it comes to handling our resources: we need to get away from our eternal belief in growth. We have to move away from ever more square meters per capita and build more compact homes.
Society as a whole is much more willing to embrace change than politicians are prepared to admit. The real resistance comes from the business community: Why should I change my successful model - diesel passenger car, concrete house - when it is running?
CCB Magazine: Will politics ever master the economic primacy?
Eike Roswag-Klinge: The historian Hannes Heer once said to me that you need a scandal for the big change. In residential construction, this is not yet as tangible as with Dieselgate, the stirring moment is missing. We are currently closing our eyes and shifting the problem to other generations. The question remains how we want to live in the future. Germany has great competence in loam and wood construction. Together with bamboo, these are the natural building materials that will lead to global change in the construction industry. If Germany takes on a leading role here, if we show how this works both technically and socially, we will once again become a role model for others. In the 1980s, we had an excellent standing in the world with activities for more ecological action. Now the wind of innovation is blowing from a different direction. We are currently no longer leaders, no role models, and not only in the automotive industry.
CCB Magazine: How do you envision the city of the future?
Eike Roswag-Klinge: Berlin? Diversity of lifestyles between living and working. Social mix, tolerance and integration. Car-free city center. Green and vibrant! Berlin has the potential to double, provided that its ecological footprint is optimized. The Berlin-Brandenburg resource region could be largely reconstructed and supplied by regional resources.
CCB Magazine: Sounds like a fairy tale. One last question: how do you actually live?
Eike Roswag-Klinge: Oh, I live in a formerly occupied house in the Adalbertstraße. Climatically a catastrophe, but we are on it. We plastered the walls with clay. Together with the bamboo surfaces, this creates a pleasant room climate. We also do without ventilation technology and ventilate manually. I always keep the windows open.
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