Frei Otto’s contribution is much greater than his act of bringing the tent into the 20th century and making it part of the current architectural vocabulary would suggest. Not only did he highlight minimal lightweight structures in architecture as a liberating force and bridge to natural or organic form, but his formulation of membrane and cable-net surface and convertible structures, as well as lattice grid shells, led to the realization that they could be used to advance an adaptable and flexible approach to building. This had the additional property of optimizing the consumption of energy and materials while being more responsive to changing human requirements. He sought to apply economical lightweight solutions on a large scale to solve environmental and microclimatic adaptation in harsh regions in simple, ingenious ways.

In place of the artist-architect who creates from his imagination, Otto substituted automatic iterative processes to produce a series of structures from which he selected the fittest. Coincidentally, they were often the most beautiful. This is encapsulated in his operational phrase “form finding,” a procedure whereby he classified structural shapes into systems and then chose one from among the many that best fit the task.

From 1931 to 1943, Otto attended Schadow School at Zehlendorf, Berlin, as a trainee mason. In World War II, he served as a fighter pilot in the German air force, an experience that unquestionably conditioned him to think in terms of lightweight solutions in architecture. At the end of a period of compulsory labor service, Otto studied architecture at the Technical University in Berlin under Freese, Bickenbach, and Jobst. Soon after this, he founded a studio at Zehlendorf (1952–58). Its activities were later transferred to Stuttgart, where Otto established his new Institute for Lightweight Structures. Otto worked closely with Peter Stroymeyer, a German tent manufacturer who, from the early years, served as both a client and a source of practical advice on tent fabrication techniques and design.

Historically, European urban tents were fabricated with a simple predetermined geometry; consequently, there was no need for architects or engineers to adopt a form-finding procedure. Otto broke with tent tradition and brought the tent into the 20th century by introducing more complex surface shapes that demanded a more sophisticated approach in determining their true shape. This happened in the 1950s when the Otto analysis of complex surface structures was only beginning. Otto employed models to define and test the behavior of his shapes. Before the mid-1960s, his textile pavilions were made up of primary anticlastic saddle shapes arranged additively, often in repetitive symmetrical compositions.

The small Bundesgarten textile pavilions are among Otto’s most elegant early constructions, both for their beauty and for their simplicity. The best are the riverside shelter and dance pavilion at Cologne (1957) and the small star pavilions at Hamburg (1963). These modest tent shelters integrated aesthetics with construction and display an unusual purity of conception that was rarely equaled in the later, larger, more technically elaborate structures that followed.

The German Pavilion of the Federal German Republic at Expo ’67 (Montreal) represented a significant departure, being many times larger and having a picturesque combination of low funnel-shaped anchor points and eye-shaped cable-loop high points attached to masts in a deliberately asymmetrical configuration, suggesting the up-and-down physical terrain of Germany.

The restaurant pavilions at the Swiss National Exhibition at Lausanne (1964) introduced cable nets for the first time to strengthen and support a membrane. Prior to this, all Otto’s roofs were fabricated from cotton canvas with modest spans of 20 to 30 meters. The Lausanne restaurant pavilions marked a new technical stage in modern tensile roofs, when they could be said to have come of age in their introduction of a new cable-net technology.

Otto’s next great opportunity came after he was appointed roof design consultant by Gunter Behnisch, who won the competition for the main stadium and indoor arenas for the Munich Olympics (1972), with a scheme inspired by the Montreal German Pavilion. The Olympic roofs realized an entirely new scale for this type of structure, which stimulated the development of purely mathematical computer-based procedures to determine their exact dimensions, shape, and behavior in parallel with elaborate modeling techniques that allowed the new mathematical procedures to be cross-checked.

Otto’s versatility and restless creativity led him to explore new types of systems and applications that exploited such unrecognized properties of tents as their flexibility and economical use of material to achieve new goals of adaptability and responsiveness to changing human and environmental needs. His convertible or retractable roofs are an instance of this. These roofs had a variable geometry that allowed them to be mechanically extended or retracted—in effect, they were converted into self-erecting and self-striking tents. A number of such convertible roofs were erected over swimming pools and sporting facilities in Germany, France, and elsewhere, but none proved so sculpturally captivating or appropriate, in contrast with the historical ruin that it covers, as the Open-Air Theater at Bad Hersfeld, Hessen (1968).

Following completion of the Munich Olympic roofs, Otto received a variety of commissions, including the delightful umbrella roofs at Cologne (1971); the roofs of the Conference Centre at Mecca, Saudi Arabia (1974); the timber-grid-shell Multi-Purpose Hall and Restaurant at Mannheim (1975); a sports complex and stadium at King Abdul Aziz University, Jeddah (1975–78); an aviary for Munich (1980); and the Diplomatic Club at Riyadh (1985).

Less active in the 1980s, Otto created a series of production pavilions for a German furniture manufacturer (1988) based on his IL test structure at Vaihingen, a series of inverted bowls for his German pavilion at the Seville Expo (1992), and a remarkable Gothic roof cover for the old shell of St. Nikolai Church, Hamburg (1988).

After 1972, Otto focused increasingly on the study and interpretation of biological structures, at the same time pursuing and extending his research into grid shells and other topics.

Otto must be ranked with Felix Candela, Richard Buckminster Fuller, and Pier Luigi Nervi as a structural innovator. He was responsible for bringing the tent into line with 20th-century structural and materials technologies and thereby creating a new range of flexible building types. He is less an architect in the conventional sense and much more an innovator and experimenter who worked in collaboration with other architects and structural researchers. His most unique creation was his Institute for Lightweight Structures at Vaihingen, which depended so much on his personal vision that it could not be continued without him. Because he was interested in minimal structures, Otto was driven to explore minimal lightweight structures in nature to further his objectives.

PHILIP DREW

Sennott R.S. Encyclopedia of twentieth century architecture, Vol.2 (G-O). Fitzroy Dearborn., 2005.  

1925 Born in Siegmar, Saxony, 31 May;

Attended the Technische Universität, Berlin;

1952 Degree in engineering;

1954 Doctorate in engineering;

1943-45 Served in the German Air Force;

1945-47 Prisoner of War, France;

1946-47 Prison camp architect, Depot 501, Chartres, France;

1952-58 Private practice, Zehlendorf, Berlin;

1953-74 Adviser to L. Stromeyer and Company, Constance, West Germany;

1957 Founder, Development Center for Lightweight Construction, Berlin;

1958-68 Established architecture studio in Zehlendorf;

1968 Studio in Warmbronn, West Germany;

1964-91 Professor, director, Institute for Lightweight Structures, University of Stuttgart;

1958 Visiting professor, Washington University, St. Louis, Missouri;

1960 Visiting professor, Yale University, New Haven, Connecticut;

1962 Visiting professor, Massachusetts Institute of Technology and Harvard University, Cambridge;

1962 Visiting professor, University of Maracaibo, Venezuela;

1966 Visiting professor, National Institute of Design, Ahmedabad, India;

1969 Visiting professor, Ulm, West Germany;

1971 Visiting professor, International Summer Academy, Salzburg, Austria;

1968 Honorary fellow, American Institute of Architects;

1970 Member, Akademie der Künste, Berlin;

1980 Aga Khan Award for Architecture, with Rolf Gutbrod;

1982 Honorary fellow, Royal Institute of British Architects;

1983 Member, Academia di Archaeologica, Lettere et Belle Arti, Naples;

1983 Member, Académie d’Architecture, Paris;

1987 Member, International Academy of Architecture, Sophia, Bulgaria;

9 March 2015 Died, Leonberg, Baden-Württemberg, Germany 

Selected Publications

Das hängende Dach: Gestalt und Struktur, 1954

Zugbeanspruchte Konstruktionen (co-editor with R. Trostel and F.K. Schleyer), 2 vols., 1962, 1966; as Tensile Structures: Design, Structure, and Calculation of Buildings of Cables, Nets, and Membranes, translated by D. Ben-Yaakov and T. Petz, 2 vols., 1967, 1969

IL-Publications (editor), 25 vols., 1969–85

Natürliche Konstruktionen (with others), 1982

Schriften und Reden, 1951–1983, edited by B. Burkhardt, 1984

Gestaltwerdung Zur Formenentstehung in Natur, Technik, und Baukunst, 1988

Frei Otto's principal publications in German are available in English translations. His early reports from Entwicklungsstätte für den Leichtbau (EL) at Berlin-Zehlendorf, which commenced in January 1958, are not generally available. The later IL-Publication series (see Selected Publications) in 25 volumes that began publication in 1969 provides valuable detailed technical reports on the form-finding and modeling procedures, as well as reporting presentations at colloquiums, at the Institut für leichte Flächentragwerke (IL) at the Universität Stuttgart, at its site in Stuttgart-Vaihingen.

Doumato, Lamia, Frei Otto’s Tensile Structures: A Selected Bibliography, Monticello, Illinois: Vance Bibliographies, 1979

Drew, Philip, Frei Otto: Form und Konstruktion, Stuttgart, Germany: Hatje, 1976; as Frei Otto: Form and Structure, London: Crosby Lockwood Staples, and Boulder, Colorado: Westview Press, 1976

Glaeser, Ludwig, The Work of Frei Otto, New York: Museum of Modern Art, 1972

Roland, Conrad, Frei Otto—Spannweiten: Ideen und Versuche zum Leichtbau, Berlin: Ullstein, 1965; as Frei Otto: Tension Structures, translated by C.V. Amerongen, London: Longman, and New York: Praeger, 1970

Schanz, Sabine, Frei Otto, Bodo Rasch: Gestalt finden: Auf dem Weg zu einer Baukunst der Minimalen: Der Werkbund zeigt Frei Otto, 1995

Frei Otto zeigt Bodo Rasch: Ausstellung in der Villa Stuck, München, anlässlich der Preisverleihung des Deutschen Werkbundes Bayern 1992 an Frei Otto und Bodo Rasch, Stuttgart, Germany: Axel Menges, 1995; as Frei Otto, Bodo Rasch: Finding Form: Towards an Architecture of the Minimal: The Werkbund Shows Frei Otto. Frei Otto Shows Bodo Rasch: Exhibition in the Villa Stuck, Munich, on the Occasion of the Award of the 1992 Deutscher Werkbund Bayern Prize to Frei Otto and Bodo Rasch, Stuttgart, Germany: Axel Menges, 1995

Teague, Edward H., Frei Otto: A Bibliography and Building List, Monticello, Illinois: Vance Bibliographies, 1985

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