Frei Otto

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Frei Paul Otto (born May 31, 1925 in Siegmar ; † March 9, 2015 in Warmbronn ) was a German architect , architectural theorist and university professor . His work in lightweight construction with steel mesh , mesh trays and other tensile structures made him one of the most important architects of the 20th century. Along with Richard Buckminster Fuller and Santiago Calatrava, he is one of the most important representatives of biomorphic architecture ( organic architecture ). Otto's architectural goal and ideal was to build with a minimum of material, space and energy, which also made him a pioneer of ecological building . With his “light, flexible buildings” he hoped for “a new, open society”. After Gottfried Böhm, Frei Otto is only the second German architect to have received the Pritzker Prize, the world's most important architectural award.

Olympiapark in Munich with the Olympiastadion (back), Olympiahalle (right) and Olympic swimming pool (bottom left)

life and work

The beginnings

His first name Frei goes back to his mother, as this was her life motto. Otto's parents were members of the German Werkbund . Originally Frei Otto wanted to be a sculptor like his father and grandfather . At the commercial school Otto came into contact with gliding and model making through his teacher . When he acquired his glider license, he was also able to gain knowledge of lightweight construction methods and frame-tensioned membranes. In 1943 he began his architecture studies at the Technical University in Berlin , which was interrupted by his military service. In the same year he was trained and used as a fighter pilot.

Academic years

Otto was eventually taken prisoner by the French in Nuremberg . While still in captivity, he was involved in the design of a prisoner-of-war camp in Chartres with several buildings in an inexpensive lightweight construction. An inspiration for him was the daily sight of the stone lightweight construction in the shape of the cathedral of Chartres . In 1948 he resumed studying architecture at the Technical University of Berlin. In 1950 he was selected by his faculty as a scholarship holder to study in the United States for six months. On his trip to America he got to know the leading architects of his time and their buildings: Erich Mendelsohn , Ludwig Mies van der Rohe , Richard Neutra , Frank Lloyd Wright , Eero Saarinen and Fred Severud. His friendship with Ludwig Mies van der Rohe grew out of this study trip. Later, at his request, he corrected the statics of the Neue Nationalgalerie in West Berlin by replacing the four main pillars originally planned with two inconspicuous pillars on each side. Otto was also a scholarship holder of the German National Academic Foundation during his academic years .

In the office of civil engineer Fred Severud in New York, he saw the model of the Dorton Arena in Raleigh (North Carolina) based on a design by Matthew Nowicki , the first large structure with a hanging roof. The saddle-shaped curved roof of the Dorton Arena is a rope net that was suspended from two semicircular, opposite and slightly sloping edge ropes. The two edge ropes cross at the edge of the roof and stabilize each other in the ground with horizontal steel girders. This concept impressed Otto so much that in 1952/53 he wrote his doctoral thesis on this new construction technology.

In 1954 he published his dissertation entitled “The hanging roof”, which for the first time comprehensively presented the structural engineering of tensile structural structures. During this work he met Peter Stromeyer, the managing director of a company for large tent construction in Constance. Stromeyer made all of his tent structures for him, including the sensational German pavilion for the world exhibition Expo 67 in Montreal (1967). Another consequence of his dissertation was invitations to visiting professorships in the USA, including as visiting professor at Washington University in St. Louis (1958), at Yale University in New Haven (1960) and in 1962 at the University of California in Berkeley, on MIT and Harvard University .

Practitioner, founder and visionary

In 1952 Otto opened his own architecture office in Berlin-Zehlendorf , and in 1957 he founded a development center for lightweight construction . In 1958 he was a guest lecturer at the Ulm School of Design , where he led a number of projects. In the same year he became a member of the architectural group GEAM (Groupe d'Etudes d'Architecture Mobile). At the Technical University of Berlin, he founded the research group Biology and Building in 1961/62 with the biologist Johann-Gerhard Helmcke , in which doctors, palaeontologists and architects researched natural constructions based on pneumatic and biological construction principles. In 1963, for example, he designed the free-standing bell tower of the Evangelical Church in Berlin-Schönow based on the model of the skeleton of a diatom . The Institute for Lightweight Structures (IL), which Otto founded in 1964 at the Technical University of Stuttgart , served as a model for the German pavilion at Expo 67 in Montreal . In 1969 he was appointed head of the Collaborative Research Center 64 “Wide-span surface structures” of the German Research Foundation . In July 1984 this project was continued by the Collaborative Research Center 230 “Natural Constructions - Lightweight Construction in Architecture and Nature” until December 1995 at the Institute for Lightweight Structures . In 1976 he was appointed full professor at the University of Stuttgart and taught there until his retirement in 1990. The Institute for Lightweight Structures ( IL ) now operates under the name Institute for Lightweight Design and Construction ( ILEK ) and is headed by Werner Sobek .

There aren't many buildings for which Otto is solely responsible; many of his buildings were created in collaboration with colleagues and with the involvement of the users. Otto described himself primarily as a source of ideas. “I haven't built much. I have devised many 'castles in the air'. ”His biomorphic designs do not owe their existence to his art of creation, but are based on the finding of forms from naturally occurring structures. "The form is not created, but determined experimentally, because it is first and foremost an expression of the prevailing static forces and is the result of a reaction to them," is how architecture critic Falk Jaeger describes Otto's design process.

Since the 1980s Otto and his student Mahmoud Bodo Rasch and his architectural office Rasch + Bradatsch , from 1998 SL Rasch GmbH Special and Lightweight Structures , have been realizing tent roof constructions in the Islamic area, including a tent city for the Hajj pilgrims in Mecca .

Roof structures

The tent-like roof structures are among Otto's most famous structures. One of his first tent roof constructions was the star wave tent in Cologne's Tanzbrunnen in 1957 on the occasion of the Federal Horticultural Show in 1957 . Further tent constructions at other exhibitions should follow. To optimize the shape of the roof, Otto experimented with wire models, which he dipped in soapy water and which were then covered by a soapy skin with the smallest possible surface area, a minimal area . For this purpose, a soap skin machine with a climatic chamber was specially developed and built in order to systematically record and measure the geometry of the soap skin models. This basic form, however, only represents a part of his ideas and buildings, further elementary forms are the tires, lattice shells and rope nets. He then transferred this natural formation principle to the rope nets by hanging these nets, stabilizing their shape and finally tipping them over. Using this method of shaping, he also designed lattice shells from long wooden slats, as was the case worldwide for the first time with the Multihalle in Mannheim .

Japanese pavilion, Expo 2000 , Hanover

The Japanese pavilion for the Expo 2000 in Hanover, which he designed together with Shigeru Ban , is a further development . Here the supporting structure initially consisted only of curved cardboard tubes, which, however , had to be reinforced with wooden slats at the request of the test engineers .

With Günter Behnisch and his architecture office, he realized the roofing of the main sports facility area on the Olympic site in Munich from 1968 to 1972 . In 2002, the architecture magazine Häuser voted this ensemble the best German building of all time. The roof construction chosen is ultimately based on his drafts after Behnisch turned to the idea provider himself due to unexpected difficulties (too large a span). Nevertheless, the edge ropes and the roof supports were far too massive for Otto. The lead civil engineers Fritz Leonhardt and Jörg Schlaich were finally able to implement their concept of static safety. In contrast, the airy and almost invisible large aviary in Munich's Hellabrunn Zoo is much more in keeping with his ideas of lightweight construction. This facility has now become a landmark of the zoo. With the transience and beauty of his materials, he also illustrated a tour of Pink Floyd in 1977 in the form of huge inverted umbrellas. For the Stuttgart 21 project , at the request of Christoph Ingenhoven, he designed the “Lichtaugen” - teardrop-shaped skylight openings in the park that rest on the platforms as floor pillars flowing downwards (“chalice supports”). In August 2010 he said that the construction project should be stopped because of the geologically difficult local subsoil and the resulting dangers.

Bridge constructions

Various bridge constructions come from Frei Otto, which are noticeably light both in the suspension and in the design of the side surfaces. One example can be found in the Ruhr area: the pedestrian bridges in the Mechtenberg landscape park .


Frei Otto worked as an architect in his studio in Warmbronn near Leonberg until the end of his life , together with his wife Ingrid and his daughter and architect Christine Otto-Kanstinger. However, increasing blindness limited his options. Otto was buried in the Warmbronn cemetery. Otto had been married to his wife Ingrid Smolla since 1952 and left behind four other children: Angela Boley, Bettina Otto-Matthes, Dietmar Otto and Erdmute Böcker.


His extensive work archive is kept by the Southwest German Archive for Architecture and Civil Engineering ( saai ) in Karlsruhe . The saai showed in cooperation with the Wüstenrot Foundation and the ZKM Karlsruhe , the largest ever exhibition of Frei Otto's oeuvre of November 5, 2016 to March 19, 2017, entitled Frei Otto. Think in terms of models .


On June 25, 2018, the furniture company Wilkhahn , the Federal Chamber of Architects and the German Sustainable Building Council (DGNB) invited a number of architecture professors and architects to a symposium which presented and discussed "Frei Otto's ideal legacy". In the mid-1980s, Otto designed four tent roof pavilions made of light wood for Wilkhahn. Otto's only industrial building with a lot of view and space was created with the participation of the workforce. Wilkhahn managing director Jochen Hahne said at the symposium on Otto's architectural legacy: "No matter what ideas and future-oriented projects you are planning today, Frei Otto was already there." His ecological, socially and culturally shaped design principles, along with innovative and experimental form-finding, had more than ever existed.

Retrospective (selection)

Buildings (selection)

Honors and awards (selection)


"A brilliant man, more a scientist than an artist, full of original ideas, balanced and thoughtful in his views."

- Walter Gropius , 1963.

“Only once in a generation does someone invent a whole new universe of ideas and solutions. And that was it: Free. "

“From very early on we were fascinated by Otto's ability to design space. These buildings that don't seem to exist. They are so delicate - like butterfly wings. "

- Peter Cook , 2005.

“There is once again a huge interest in lightweight constructions, in tent-like structures. Otto's networks and all these things that he did in his institute have moved back into focus. "

- Zaha Hadid , 2005.

“Frei Otto did not patent his inventions but gave them to everyone so that future designers can benefit from them. He was a great humanist. "

- Kristin Feireiss , 2015.

“Frei Otto forever changed the way we think about buildings. [...] He questioned what was there and went back to nature. He was way ahead of his time. "

- Frank Gehry , 2015.


Fonts (selection)

  • Frei Otto (Hrsg.): Tensile stressed constructions. Design, structure and calculation of structures made of ropes, nets and membranes. Ullstein, Frankfurt, Berlin.
    1962: Volume 1: Pneumatic constructions by Frei Otto. Calculation of the membranes by Rudolf Trostel. Tie rods in Frei Otto's building site.
    1966: Volume 2: Basic terms and overview of the tensile stressed structures.
  • Frei Otto, Rainer Barthel, Berthold Burkhardt: Natural constructions. Forms and constructions in nature and technology and processes of their creation. DVA, Stuttgart 1982, ISBN 3-421-02591-6 .
    - about construction bionics .
  • Writings and speeches 1951–1983. Frei Otto. Edited by Berthold Burkhardt. Vieweg, Braunschweig 1984, ISBN 3-528-08687-4 , excerpts in Google books .
  • Light. A work of the sub-project C1 "Creation processes of objects in nature and technology" in the Collaborative Research Center 230 "Natural Constructions". Text and sketches by Frei Otto. University of Stuttgart, Collaborative Research Center 230, 1985.
  • Klaus Bach: Soap bubbles. A research work by the Institute for Light Surface Structures on minimal areas = forming bubbles. Edited by Frei Otto. Krämer, Stuttgart 1988, 400 p., Numerous. Ill., ISBN 3-7828-2018-5 .
  • Frei Otto: Formation. On the creation of forms in nature, technology and architecture. Müller, Cologne 1988.
  • Frei Otto: The hanging roof. Shape and structure. With afterwords by Frei Otto, Rainer Graefe and Christian Schädlich. DVA, Stuttgart 1990. (Reprint of the dissertation published by Bauwelt-Verlag in 1954 - the first summarizing representation of tensile surface structures.)
  • Klaus Dunkelberg: Bamboo - building with plant sticks / Bamboo. (= Reports from the Institute for Lightweight Structures at the University of Stuttgart , 31). Edited by Frei Otto. Krämer, Stuttgart 1996, ISBN 3-7828-2031-2 . (German English)

Literature (selection)

  • Conrad Roland : Frei Otto - Spans. Ideas and attempts for lightweight construction. A workshop report. Ullstein, Berlin 1965.
  • Conrad Roland: carrying skins. Edited by the Association of Freelance Swiss Architects. Editing: Lisbeth Sachs. Niggli, Niederteufen 1973, (= archithese. Issue 6).
  • Karin Wilhelm: Portrait Frei Otto. Quadriga, Berlin 1985.
  • Conrad Roland: Architects - Frei Otto. Edited by Dieter Hezel. IRB Verlag, Stuttgart 1988, ISBN 3-8167-1817-5 .
  • Karin Wilhelm: Planned Poetry. Selected works by Frei Otto and his teams 1955–2000. Edited by Christina Ossowski. Leonberg 2001, ISBN 3-933636-07-8 .
  • Winfried Nerdinger (Ed.): Frei Otto. The complete work. Build easily, design naturally. With the collaboration of Irene Meissner, Eberhard Möller and Mirjana Grdanjski. Birkhäuser, Basel & Architekturmuseum der Technische Universität München 2005, ISBN 3-7643-7233-8 .
  • José Luis Moro (Ed.): Frei Otto for the 85th. Festschrift for the symposium on the occasion of his 85th birthday on October 26, 2010. With an interview and contributions by Berthold Burkhardt, Stefan Polónyi u. a. University of Stuttgart, Institute for Design and Construction, Stuttgart 2013, ISBN 978-3-9812662-1-4 .
  • Juan Maria Songel: Conversation with Frei Otto. Princeton Architectural Press, New York 2010, ISBN 978-1-56898-884-9 , excerpts from Google Books .
  • Rudolf Finsterwalder (ed.): Form follows nature. A history of nature as a model for form finding in civil engineering, architecture and art. With a foreword by Kristin Feireiss and an unpublished interview with Frei Otto. 2nd, revised edition, Birkhäuser, Basel 2015, ISBN 978-3-0356-0790-1 , (German / English), table of contents , review:.
  • Rainer Barthel: With ease against brutality - On the death of Frei Otto . In: Stahlbau , Vol. 84 (2015), no. 5, pp. 358–365.
  • Irene Meissner, Eberhard Möller: Frei Otto: research, build, inspire / a life of research, construction and inspiration. Detail , Munich 2015, ISBN 978-3-95553-252-9 , (German / English), reading sample .
  • Walter Scheiffele: The light house: utopia and reality of membrane architecture. Edition Bauhaus 44, Spector Books, Leipzig 2016, ISBN 978-3-944669-45-8 .
  • Georg Vrachliotis (Ed.): Frei Otto. Think in terms of models. Spector Books, Leipzig 2017, ISBN 978-3-95905-075-3 , exhibition volume.
  • Georg Vrachliotis: Frei Otto, Carlfried Mutschler , Multihalle . Spector Books, Leipzig 2017, 255 pp., 192 illustrations, ISBN 978-3-95905-192-7 , (German / English).
  • Reiner Zeeb: micro-construction of nature and the architectural future. Building for a different society. Frei Otto. In: ders., Art Revolution and Form. Verlag Ludwig, Kiel 2017, ISBN 978-3-86935-309-8 , pp. 249-284.
  • Joachim Kleinmanns: The German pavilion at Expo 67 in Montreal. A key work of German post-war architecture. DOM publishers, Berlin 2020, ISBN 978-3-86922-751-1 , table of contents , review:.

Films (selection)

  • Frei Otto: Spanning the Future. Documentary, USA, 2015, 87 min., DVD: 60 min., Book: Michael Paglia, director: Joshua V. Hassel, production: Simon K. Chiu, cinema premiere: October 10, 2015 at the Architectuur Film Festival Rotterdam (AFFR), Film page , video interview with the producer , (12:40 min., English).
  • The built utopia. The Munich Olympic Stadium. Documentary, Germany, 2014, 4:35 min., Script and director: Klaus Uhrig, production: Bayerischer Rundfunk , series: dot. Simply knowledge , first broadcast: March 21, 2014 on Bayerischer Fernsehen, table of contents with online video from BR.
  • The dream of the tree house. Frei Otto's eco-house project in Berlin. Documentary, The Netherlands, 2011, 65 Min, written and directed. Beate Lendt, production: x mage, Cinema Premiere: October 8, 2011 in Architectuur Film Festival Rotterdam (affr) Summary of , film leader .
  • Frei Otto. Of soap bubbles and tents. Documentary, Germany, 2005, 60 min., Script and director: Louis Saul, production: SWR , arte , first broadcast: arte , April 22, 2005, production: megaherz , SWR , arte , summary by megaherz ( Memento from April 15, 2013 in the web archive ).
  • Build like nature - Frei Otto and the Munich Olympic roof. Documentary, Germany, 2003, 14:40 min., Book: Magdalena Heinrichs, director: Karin Atzenbeck, production: Inter / Aktion, BR-alpha , MDR , WDR , SWR , Deutsche Welle , series: Milestones in natural science and technology , summary from Planet School.

Web links

Commons : Frei Otto  - Collection of images, videos and audio files





Individual evidence

  1. a b Frei Otto: 'Less is more', this word fascinated me: Less houses, less material, less concrete and less energy, but building humanely using what is available: earth, water, air. Build close to nature and make a lot out of a little [...]. Better not build at all than build too much! These were old and new goals. In: Architektur Natur , excerpt, (PDF; 2 p., 12 kB), Warmbronner Schriften 7, Christian-Wagner-Gesellschaft, Warmbronn 1996.
  2. a b Cornelia Escher, Kim Förster: “I was Dr. Tent. “Frei Otto on adaptability, ecology and economy in building. Interview on October 22, 2012 in Warmbronn. In: ARCH + - Zeitschrift für Architektur und Städtebau , 210, 2013, pp. 72–80, (PDF; 9 pp., 17.6 MB), beginning of the article of the original (German, English).
  3. a b Hanno Rauterberg : The Lord of the Moment. His love is for the light and flexible. In: Die Zeit , January 2, 2003, No. 2, interview.
  4. a b Frei Otto, 2015 Laureate. In: Pritzker Architecture Prize , accessed on March 11, 2015.
  5. a b Robin Pogrebin: Pritzker Prize for Frei Otto, German Architect Announced After His Death. In: The New York Times , March 10, 2015.
  6. Martin Schuster: Seminar work on design history: Frei Otto. In: University of Stuttgart , 1997.
    Dieter Wunderlich: Biography Frei Otto 1925–2015.
  7. a b c Kateryna Serebryakova: Captured by nature: Frei Otto, architect. ( Memento from March 3, 2016 in the Internet Archive ) In: University of Stuttgart , April 10, 2006.
  8. a b c d Martin Schuster: Seminar work on design history: Frei Otto. Introduction. In: University of Stuttgart , accessed on March 12, 2015.
  9. In: Juan Maria Songel: A Conversation with Frei Otto. Princeton Architectural Press, New York 2010, ISBN 978-1-56898-884-9 , p. 28.
  10. Till Boettger: Neue Nationalgalerie, Fig. 40. In: Threshold spaces: transitions in architecture. Analysis and design tools. Birkhäuser, Basel 2014, ISBN 978-3-03821-589-9 , p. 69, e-book .
  11. Claus Uwe Derichs: Self-forming formation of form as a design vision. Consultation with Frei Otto. ( Memento of May 3, 2005 in the Internet Archive ). In: werk und zeit , magazine of the German Werkbund , 2002, April, issue 1.
  12. 90 years, 90 heads. In: A series of portraits for the 90th anniversary of the German National Academic Foundation. December 1, 2018, accessed April 12, 2020 .
  13. ^ "Fred Severud (1899-1990), civil engineer of Norwegian descent, founded Severud Associates in New York. He was responsible for the structures of Madison Square Garden in New York City and the Gateway Arch in St. Louis, Missouri. ”In: Juan Maria Songel: A Conversation with Frei Otto. Princeton Architectural Press, New York 2010, ISBN 978-1-56898-884-9 , p. 84.
  14. TS Sprague: "Floating Roofs": The Dorton Arena and the development of modern tension roofs. In: Paulo J. da Sousa Cruz (Ed.): Structures and Architecture: New concepts, applications and challenges. Taylor & Francis, London 2013, ISBN 978-0-415-66195-9 , pp. 1096-1102.
  15. Frei Otto on the future of tent construction. In: Detail 2000, issue 6.
  16. a b Rainer Barthel: In memory of Frei Otto. In: Technical University of Munich / Faculty of Architecture , April 8, 2015.
  17. Frei Otto: Architektur Natur , (PDF; 2 p., 12 kB), Warmbronner Schriften 7, Christian-Wagner-Gesellschaft, Warmbronn 1996.
  18. Collaborative Research Center 230 “Natural Constructions - Lightweight Construction in Architecture and Nature”. In: , (PDF; 2 pp., 16 kB), accessed on May 4, 2016.
  19. The castles in the air. Third Pinakothek: Architecture Museum honors Frei Otto. In: Münchner Merkur , May 25, 2005.
  20. a b Quoted by Falk Jaeger : Engineer portrait. Frei Otto. In: db deutsche bauzeitung , June 2, 2005, No. 6, (Original title: Engineer portrait . Frei Otto. Architect, designer and visionary, promoter of lightweight construction ).
  21. History - Tanzbrunnen Cologne. In:
  22. Otto's forerunner in the use of rope nets was the Russian architect Vladimir Schuchow (1853–1939).
  23. Japan Pavillion Expo 2000 Hanover. In: wikiarquitectura , (English), on September 21, 2016.
  24. ^ A b "Germany's Best Buildings": The Olympic Stadium in Munich is No. 1. In: , November 18, 2002, press release from G&J , Criteria .
  25. Large aviary . ( Memento of July 6, 2011 in the Internet Archive ). In: Hellabrunn Zoo, Munich.
    Photo: Hellabrunn Zoo - large aviary. ( Memento from April 2, 2015 in the Internet Archive ) In: , accessed on March 11, 2015
    Christoph Randl: getting on in years. Aviary in the Hellabrunn Zoo in Munich. In: db deutsche bauzeitung , May 30, 2011.
  26. Convertible stage screens for a Pink Floyd concert tour. In: Architekturmuseum der TU München , 2005, accessed on March 11, 2015.
  27. Milestone in Stuttgart: The first sample cup was concreted. In: ingenhoven architects , March 18, 2016, accessed May 5, 2016.
  28. ^ Werner Sobek : S21 underground station Stuttgart. In: , accessed on November 5, 2017.
  29. a b Video: Animation. Stuttgart 21 - A train station is going underground. In: SWR Aktuell , August 5, 2014, 0:42 min. And
    picture gallery: Large-scale project Stuttgart 21: How the train station should look. In: manager magazin , November 30, 2010.
  30. Hans Monath, Andreas Böhme: Railway should pull 21 emergency brake near Stuttgart. In: Der Tagesspiegel , August 26, 2010.
  31. Stuttgart 21 architect calls for an immediate construction stop. In: , August 26, 2010, accessed on March 11, 2015.
  32. Mechtenberg pedestrian bridges near Gelsenkirchen. In: Prof. Schmidt & Partner , accessed on March 11, 2015.
  33. Photo: Frei Otto's grave. In:
  34. ^ Fred A. Bernstein: Frei Otto, Architect, Dies at 89; the Soap Bubble What inspiration. In: The New York Times , March 10, 2015.
  35. Frei Otto (1925-2015). In: South-West German Archive for Architecture and Civil Engineering ( saai ), accessed on May 4, 2016.
  36. a b Frei Otto. Think in terms of models. In: ZKM , 2016/17, accessed on March 25, 2017.
  37. Sabina Strambu: architecture symposium in and heritage of Frei Otto. In: Detail , June 25, 2018.
  38. ^ Frei Otto's conception of a workplace. In: Detail , October 11, 2018.
  39. ^ A b Ulla Hanselmann: Architecture of the century from Stuttgart. A tent for "Swinging Germany". In: Stuttgarter Zeitung , January 7, 2020, with photo gallery.
  40. ^ Johanne Arzberger: Fichtelgebirge. 50 years and still very modern. In: Frankenpost , June 16, 2019.
      Photo: Luisenburg Festival under the sign of change. In: , May 23, 2019.
  41. ^ A b Tuwaiq Palace, Riyadh, Saudi Arabia. ( Memento of April 24, 2001 in the Internet Archive ). In: Aga Khan Award for Architecture.
  42. ^ Production pavilions of the Wilkhahn company in Bad Münder. In: Architekturmuseum der TU München . Exhibition “Frei Otto - Build lightly, design naturally” 2005, accessed on March 11, 2015.
  43. Holger Wolpensinger: Ökohaus Cornelius street. In: , 1/2006.
  44. Ulla Hanselmann: Architecture of the century from Stuttgart. A tent for “Swinging Germany” - picture 7. In: Stuttgarter Zeitung , January 7, 2020.
  45. ^ Intercontinental Hotel and Conference Center, Mecca, Saudi Arabia. ( Memento of April 22, 2001 in the Internet Archive ). In: Aga Khan Award for Architecture
  46. Big BDA Prize # 1982. ( Memento from April 2, 2015 in the Internet Archive ). In: Association of German Architects ( BDA ).
  47. ^ Exhibition of the Architecture Museum on Frei Otto
  48. Munich Olympic Park. Systems and buildings for the 1972 Olympic Games. In: Bund Deutscher Architekten / Nike 2013
  49. a b c In the documentary: From soap bubbles and tents. ( Memento from April 15, 2013 in the web archive ). First broadcast: arte , April 22, 2005.
  50. ↑ In memory of Frei Otto. “He was the light figure of architecture”. Kristin Feireiss in conversation with Christine Watty. In: Deutschlandradio Kultur , March 3, 2015.
  51. ^ Dpa : Posthumous: Architectural Prize for Frei Otto. In: Deutsche Welle , May 16, 2015.
      Tributes to Frei Otto. ( Memento of March 18, 2015 in the Internet Archive ). In: Pritzker Prize , 2015.
  52. a b c d e biography - exhibitions. In: Architekturmuseum der TU München
  53. Frei Otto. Medical Faculty Ulm. Model of the entire building. In: German Architecture Museum , February 15, 2013.
  54. ↑ Proof of exhibition in Olaf Holzapfel : fence display. In: documenta 14 , April 8 - September 17, 2017, (PDF; 17 pp., 8 MB), accessed on November 5, 2017.
  55. Bionics and Organic Architecture. In: OVB , March 30, 2013.