Javier García-Germán interviews Anne-Julchen Bernhardt and Jörg Leeser, founding partners of BeL Sozietät für Architektur, their architecture office in Cologne (Germany).
Anne and Jörg have been invited to present their work at MCH, as guest lecturer of the specialty Energy & Sustainability. Together with Diego García-Setién, architect and professor at ETSAM (UPM Madrid), they participated in the last seminar day of the specialty, titled "Time in buildings. Architecture as Infrastructure".
JGG: In architecture sustainable-oriented agendas oscillate between opposite approaches such as top-bottom versus bottom-up, high-tech versus low-tech, etc. What do you think about these dichotomies and where is your approach positioned?
BeL: Most of our projects are located in Germany. Even though we favor a low-tech approach, German building codes demand an enormous effort to preserve energy. We are not convinced that German measures such as airtight sealing of the building, wrapping buildings in thick Styrofoam envelopes, mechanical ventilation with heat pumps are sustainable. Their durability is questionable, they afford maintenance and, last but not least they impair self-build processes requiring special skills.
JGG: We have known your work in the 2016 Venice Biennale and have acknowledged your interest for the open-building approach. In what ways is your work connected to Habraken’s approach and why do you think it is still relevant?
BeL: There is little disagreement with Habraken on our side, but our involvement in self-build projects was less motivated by theory but developed typologically and economically over time. Ever since the beginning of our office we were engaged in lowcost projects (not necessarily by choice). Economical optimization has always been a driving force in our work. It is challenging to maintain architectural qualities under these circumstances especially the limitations in space and building materials. The sociological impacts came along when our work shifted towards collective housing. Group building, social interaction, liberation from patronizing expert designs and pride in one’s own work were welcomed objectives.
Unlike Hertzbergers projects such as the Diagoon houses or Frei Ottos Tiergarten Ökohaus” our projects not necessarily address idealistic clients on their quest for a liberated self-determined life. The target groups of Grundbau und Siedler and Neubau are people who simply want to find affordable housing in metropolitan areas and are willing to invest time to save money.
When we presented our project to Hermann Hertzberger he criticized the lack of architectural space in it. But complex building volumes, internal voids and extra space produce costs people are not willing to pay. Even though we are idealists ourselves we accept the pragmatism of the users.
JGG: The open-building model needs to be connected to climate and provide a bioclimatic approach. Is this objective sought in your work? Do you think bioclimatic strategies pertain to the structure or to the infill?
BeL: On Grundbau und Siedler we worked with a producer of autoclaved aerated concrete blocks and mineral insulation as a partner. The structure was erected in conventional in situ cast concrete. In the competition phase we experimented with in situ cast infralight concrete but it could not meet the energy saving standards at that time. It is not the most sustainable construction method but we are trying to move away from it.
In our current projects we aim to produce the infill mainly in wood, sooner or later also the loadbearing structure can be executed in wood, once fire regulations adapt to new constructions methods.
JGG: Introducing the arrow of time in building processes is a key question. In what ways is the open-building initiative fostering this question?
BeL: There is a controversy on the long-term effects of customization regarding its flexibility. Many 1960’s projects saw architecture as a dynamic process of constant, rather frequent modifications. Thus sophistically engineered flexible buildings were engineered at high costs. Many of those theoretically alterable structures have never been altered (there are some exceptions such as the Igus factory in Cologne by Nicholas Grimshaw)
Architectural history has shown that spatial changes rather happen on a low-tech construction level. Informal settlements, due to the scarcity of resources transform with little building material and level of detail. In developed societies do-it-yourself superstores flourish, people alter their dwellings on a more and more substantial basis.
When we look at our department store conversion we can learn that an open structure can house many programs over time with little alterations. We always aim at a maximal neutrality of spaces; the less constructive modification is necessary, the better the architecture is. The user with little effort can appropriate Grundbau and Siedler’s spatial system. Circulation consists of an excess of enfilade connections that can be closed easily to create customized configurations.
JGG: Obviously time-oriented strategies are connected to the usage of buildings. However, can these strategies be extended to the management of the material stocks which are stored within buildings? Do you think Stewart Brand’s concept of shearing layers of change is compatible with the open-building initiative?
BeL: This is one strategy. We always consider the energy bound in the construction material as a valuable resource. Especially in conversion projects we try to preserve a maximum of the existing building to continue to use the energy once invested.
JGG: Your open-building proposals have a social side. Similarly to other projects, such as Aravena’s elemental housing, your proposals empower citizens providing for instance, affordable housing. In what other ways do your proposals empower citizens? In what ways do your projects provide a social-responsive architecture? Can you please expand on these questions.
BeL: We are trying to offer an opportunity for all stakeholders to participate in the production of affordable housing. Working with a commercial investor on Grundbau and Siedler self-building created an economical beneficial environment for home buyers, tenants and investors as well. So far we tried to not be depended on political interference in the production process even though it becomes more and more obvious that the current housing crisis in Germany could only be solved with political determination.
Neubau addresses the question of planned metropolitan growth, integrating domestic and international migrants. The current need for large scale urban planning recalls the paternalistic modernist’ planning of the past. Neubau’s open-building design provokes a discourse on the relationship between society and the production of social housing.
There is also a long tradition of housing cooperatives in Germany that until recently had fallen into a deep sleep only administrating there housing stock. There is a vivid movement of micro-cooperatives in Germany now, which try to compensate for the lack of federal and municipal involvement in the production of affordable housing.
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