In November 2016, the ZKM – Zentrum fuer Kunst und Medien – Centre for Arts and Media – in Karlsruhe, Germany, inaugurated its exhibition on the works of Frei Otto entitled “Frei Otto – Thinking by Modeling” (November 05, 2016 – March 12, 2017): an exhibition unprecedented in terms of conception and extent, curated by Prof. Georg Vrachliotis. In the year before, Frei Otto had passed away, while in the same year he had been awarded the prestigious Pritzker Prize for architecture. As a result, the attention of architects, engineers and designers worldwide has been refocused on the personality, the works and the achievements of Frei Otto. The opening of the exhibition was widely picked up, attracted a lot of visitors and comes along with several “special events”, one of them being a symposium which will be held on January 26-27, 2017.
The works of Frei Otto and his research teams play an active role in current design of architecture and engineering. They are often referred to when lightweight structures or bionically inspired designs are discussed. The current attention on Frei Otto,his insights and merits should be interpreted as contributions to our heritage, prospect and responsibility. His exclamation “Stop building the way you build!“, formulated during a lecture in 1977 , is still reverberating. This outcry can be taken as an inspiration for many disciplines, be it architecture, engineering, biology or social sciences.
Frei Otto and the Institute of Lightweight Structures in Stuttgart
The establishment of the “Institute of Lightweight Structures” at the University of Stuttgart, Germany, was a starting point to a “time line” of lightweight structures at this location. Fritz Leonhardt called Frei Otto, who was at that time living and working in Berlin, to Stuttgart University. Fritz Leonhardt (1909 – 1999) was the designer of the Stuttgart television tower which was the first of its kind being constructed in reinforced concrete, the author of books dealing with “aesthetics” of bridges, and pioneer in the field of designing structures in reinforced concrete. Leonhardt had published his thoughts about lightweight structures as a “demand of our times” in 1940 , a time facing material scarcity during a devastating war which had been triggered by Nazi-influenced Germany. The lack of material, or the restriction to a certain kind of material, can be taken as a source of inspiration for lightweight construction: Eladio Dieste, Felix Candela and Robert Maillart developed their unique aesthetics by this kind of limitation. Fritz Leonhardt was aware of this special quality and in that spirit he called Frei Otto to be Professor at the the Institute of Lighweight Structures IL at Stuttgart University.
During this time, Frei Otto was dealing with the detailed design of the German pavilion for the Expo Montreal in 1967, a piece of architecture which was path breaking in many ways. A test building of the Expo roof, prototype of a cable net structure, was to become the place of location of the IL.
Joerg Schlaich was the successor of Fritz Leonhardt as Professor at the University of Stuttgart. Werner Sobek assumed the chair of Frei Otto at the Institute of Lightweight Structures in 1994. In 2001, he was additionally appointed as successor to Joerg Schlaich’s Chair. The two chairs were merged to become the “Institute of Lightweight Structures and Conceptual Design” ILEK. In 2015, Werner Sobek was awarded the “Fritz Leonhardt Prize”, a distinction awarded every three years to an engineer in recognition of outstanding contributions to the area of structural engineering. In a very emotional speech, Sobek stated his view of the necessity of lightweight structures, based on very descriptive and startling numbers .
The circle is closing: the need for lightweight structures, be they named material-efficient or low-carbon-footprint, is even more relevant in the beginning of the 21st century. Frei Otto initiated a center of knowledge which reached out to the world.
“Thinking by Modeling” – the exhibition
The exhibition is set up in two large-scaled rooms of the “ZKM” (Zentrum fuer Kunst und Medien – Center for Arts and Media) museum in Karlsruhe. The building itself was originally built as a munition factory and is a protected monument with classical elements of industrial architecture. It hosts the ZKM since 1997.
The city of Karlsruhe is also the location of the “saai” (Suedwestdeutsches Archiv für Architektur und Ingenieurbau – Southwest German Archive of Architecture and Engineering), where Frei Otto’s works have been archived after his passing away.
Due to the initiative of Prof. Georg Vrachliotis, Professor at the KIT Karlsruhe, this impressive exhibition has been realized.
The exhibition is constituted by four elements: model landscape, open archive, cosmos, and projection.
– Frei Otto’s model landscape
Frei Otto stated that “he has not built a lot” , which may apply counting the real-scale buildings constructed under his direct supervision. However at model and experimental scale, he did build an amazing amount of models . Approximately 400 models have been archived in the “saai”, about 200 of which are shown at the current exhibition. The models are arranged according to their scale, giving the visitors the impression “that they are floating through a ‘horizontal cabinet of wonder'” . The models, displayed on a table of about 50 m length, include “visionary” studies such as flying objects or large-scale enclosures, which may be taken as the “goal” of a project, as well as experimental objects, which can be understood as “starting points”. The band width of objects illustrates the spectrum of thoughts of Frei Otto and his teams.
– Frei Otto’s open archive
The open archive is considered a “central component of the exhibition”. It consists of “18 oversized filing racks, which are built around both courtyards and which provide the exhibition with its scenic stabilization”. The exhibits guide visitors through Frei Otto’s vita including relevant locations and projects of his work. The exhibition invites to profoundly deal with Frei Otto’s works and insights by offering a “freely accessible viewing warehouse and place of knowledge between presentation and storage” .
– Frei Otto’s cosmos
This section of the exhibition seems to take us to Frei Otto’s personal work bench. Wooden tables, based on the workbenches of Frei Otto’s studio in Warmbronn, display his “way of working” in an almost intimate way: it shows the process of collection, classification and cognition.
As an architect, Frei Otto is often related to as the designer of membrane and cable net structures. However, this is only one facet of his works. The general approach of detecting similarities, interpreting these similarities and of developing them into a design tool is broadly applicable. This search for form, other than the deliberacy of form, facilitates fundamental design approaches.
The “inverse way”, as described by Frei Otto, opens up new doors in the field of architectural design. Even if the tools may have changed, the quotation “the tool determines the architecture” is a key word to summarize Otto’s approach, to explain its widespread applicability, and to verify its durable validity.
– Frei Otto’s projection
A movie projection displaying Frei Otto and many of his cooperators is entitled “projection”, and indeed this label includes both the cinematic tool as well as Frei Otto’s effect of trans-disciplinary working: “The innovative potential of Frei Otto is based on the radical multidisciplinary of his thought processes between architecture, technology, science and society.”  Frei Otto achieved at a large scale, which today often still seems to be difficult at smaller dimensions: out-of-the-box thinking, exchange of information and transfer of technologies and thoughts are a most valuable approach. Frei Otto gathered not only architects and engineers, but also biologists, philosophers, sociologists and more disciplines in common projects. The alignment of different views should be taken seriously nowadays even more than ever before.
Frei Otto: heritage and prospect
The works of Frei Otto and his team are referred to throughout the world when dealing with architecture, engineering, biology. His successor Werner Sobek pointed out that “we stand of the shoulders” of persons such as Frei Otto. The basic questions, the fundamental investigations and the path breaking publications carried out by his team set an elementary groundwork for our research on how to build in and for the future.
The intensive current interest drawn to the works of Frei Otto should persist steadily. The challenges we are facing may change, but the benefits of the principles of lightweight structures as depicted by Frei Otto are lasting. His works should be taken as our heritage, as prospect and as responsibility.
Thinking by Modeling
Georg Vrachliotis (Curator), Marc Frohn (Co-Curator), Martin Kunz (Co-Curator), Joachim Kleinmanns (Co-Curator), Julia Schiffer (Project assistance), FAR frohn&rojas (Exhibition architecture), Studio Lukas Feireiss (Graphic design), ARCH+ (Media), Spector Books (Publication)
Redesign of the GLOBALE wall modules by Stadelmann Schmutz Wössner Architects (SSW) as table plain by frohn&rojas (FAR).
Organization / Institution:
ZKM Zentrum für Kunst und Medien| Karlsruhe,
Author: Irmgard Lochner Aldinger
 Frei Otto. finding form. 1925-2015. jens harzer spricht frei otto. Cherbuliez Productions GbR, 2015
 Leonhardt, Fritz: Leichtbau – eine Forderung unserer Zeit. Anregungen für den Hoch- und Brückenbau. Bautechnik, Jahrgang 18 Heft 36/37, August 1940
 Sobek, Werner: Die elektrische Stadt. Bauingenieur, Jahresausgabe 2015/2016, VDI-Bautechnik
 ZKM exhibition website, curator Georg Vrachliotis, http://zkm.de/en/event/2016/11/frei-otto-thinking-by-modeling