In 1959 Heinz Isler challenged the world of concrete shell design by proposing a series of shapes for shells that were very different from what most designers thought were logical or appropriate forms. These geometries were the result of experimentation and form finding methods that creatively explored form in shells beyond strict geometry and moved into a world of structural expression. In a similar way contemporary engineers are encountering forms for steel shells that are going well beyond established notions of geometrical optimization, pushed by extreme architectural programs and client demands.
This paper will trace the evolution of the steel and glass gridshell and examine their current development. This evolution has been impacted by the digital revolution both in terms of computation, design tools as well as fabrication technologies. Different case studies will be examined that chart this evolution of technology and look at how this has changed the way structural engineers work.
The history of steel gridshells can be seen as a natural offshoot to the development of concrete shells, and it is interesting to compare the development of gridshells to what
Grid shell evolution is influenced by both architectural development as well as the development of the techniques and tools used to imagine as well as design these structures. The following
We have noted three different gridshell structures built over the last 20 years. The first gridshell is a simple cover, very much in the tradition of the skylight that is
It is clear that there has been an evolution in the development of gridshells. These three examples show a clear progression of the drivers outside of classical structural engineering that
I would like to acknowledge the many people at BuroHappold who worked on these three exciting projects in London, New York City and Los Angeles. Also I would like to thank the architectural design teams that worked on these projects for providing us the wonderful opportunity to do such exciting work. Without your initial ideas and drive, there would be no projects
 Book: Billington, David P. The Tower and the Bridge: The New Art of Structural Engineering. Princeton University Press, 1983. ISBN 978-0-7148-4146-5 ISBN 0-691-02393-X.
 Book: Addis, Bill. Building: 3000 Years of Design Engineering and Construction. Phaidon Press Limited, 2007.
 Article Chilton, John “39 etc… Heinz Isler’s infinite spectrum of new Shapes for Shells” Proceeding of the International Association for Shell and Spatial Structures (IASS) Symposium 2009, Valencia.
 Website Wikipedia IASS and Isler https://fr.wikipedia.org/wiki/Heinz_Isler