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Urban complexity's role in a practical emergent urbanism

The translation of a presentation given to complexity scientists on the practice of urban planning

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Urban complexity's role in a practical emergent urbanism

  1. 1. The role of urban complexity in the practice of urbanism<br />Emergent Urbanism<br />Mathieu Hélie<br />Translated from the original French<br />
  2. 2. Urban complexity theories<br />Since the 1990’s, many complexity science programs have researched urban complexity.<br />
  3. 3. Pierre Frankhauser<br />French geographer Pierre Frankhauser studies the geometry of urban areas to determine their fractal dimension.<br />
  4. 4. Bill Hillier<br />A spatial configuration theory, Space Syntax predicts the probability of traffic in the urban network, and some land uses<br />
  5. 5. Michael Batty<br />Cities and Complexity is the biggest treatise specifically on complexity science applied to cities. (Cellular automata, agent-based models, mathematical equations, etc.)<br />No conclusion. The author admits that it is only an exploration.<br />
  6. 6. Nikos Salingaros<br />Urban web theory, a physical connection network<br />Definition of a fractal city<br />
  7. 7. What’s it for?<br />Up to now no theory attempts to explain how or why cities are complex and/or emergent.<br />No link to the process of urbanization.<br />« We want to know how to do our job »<br />
  8. 8. History of urbanism<br />Solutions to scale problems that appear whenever the city grows larger<br />
  9. 9. Organic urbanisation<br />The collapse of the Roman Empire ends the first attempt at urban planning<br />For the next 1000 years urbanization is a random unconscious process<br />Cities grow « organic » morphology<br />
  10. 10. Characteristics of organic urbanization<br />Land is built up as the economy necessitates<br />Economic conditions change too slowly for change to be noticeable<br />No interventions other than a code limiting new construction<br />
  11. 11. Organic urbanization still exists!<br />Where no planning system is enforced organic urbanization procedes naturally.<br />
  12. 12. Pre-industrial planning<br />In the 17th century some towns reach hundreds of thousands of inhabitants<br />The organic network becomes jammed<br />Urban planning is (re)invented<br />
  13. 13. Examples<br />
  14. 14. The grid<br />New law codes regulate property division to maintain a uniform grid for traffic circulation.<br />Usage zoning is not adopted yet<br />Code of the Americas, New York, Torino, Barcelona<br />
  15. 15. New York<br />Multiple grids collide into each other until the Plan of 1811 settles the entire island<br />
  16. 16. The metropolitan scale<br />The regular grid is impossible to navigate with hundreds of streets<br />Cities routinely reach a million inhabitants<br />Transportation systems multiply and clash with each other<br />
  17. 17. Architects provide the answer<br />The modern city will be a utopia planned with industrial science to build the city of the machine civilization.<br />The city is designed at the scale of millions of inhabitants<br />
  18. 18. Characteristics of urban planning<br />The network is planned as well as the land uses through architectural building plans and zoning codes.<br />City plans become architectural designs<br />
  19. 19. Scale problems of urban planning<br />Cities sprawl out<br />Social, economic and ecological problems<br />How can we make sustainable cities?<br />
  20. 20. Evolution of urbanization processes<br />As we progressed to modernity the process of urbanization became less spontaneous and more industrial.<br />How did this impact urban complexity?<br />
  21. 21. General theory of complexity<br />Stephen Wolfram, A New Kind of Science<br />Christopher Alexander, The Nature of Order<br />
  22. 22. The Wolfram method<br />Observing nature allows us to formulate theories of natural laws<br />We have to guess these laws and test them with experiments<br />Observing the computational universe allows us to know the precise laws exactly<br />
  23. 23. Wolfram’s classes of phenomena<br />Type I: dead<br />Type II: linear or regular<br />Type III: fractal hierarchical<br />Type IV: fractal random<br />
  24. 24. Type II urbanization<br />
  25. 25. Type III urbanization<br />
  26. 26. Type IV urbanization<br />
  27. 27. Alexander<br />Emergent processes are the key to natural or « organic » morphology<br />“I believe that the whole idea about the natural environment has been turned on its head actually in a very strange way.  For about a quarter of a century, people have been in effect obsessed with saving the environment - which is of course a very sensible thing to do when it's being ravaged and destroyed. <br /> <br />But the real problem is that we won't be OK, in terms of building or in terms of nature or anything else, until we learn how to make nature.”<br />
  28. 28. Morphogenesis<br />The form of a living system is the result of the reiterating local actions of elements following shared geometric rules. (DNA, physical law, computer programs)<br />
  29. 29. Emergence of urban order<br />A single geometricruleregulates the growth of randombuildings<br />
  30. 30. Morphogenetic urbanization<br />Dividing and subdividing land into a city works on the same principles as natural cell division<br />The complexity of the urban system depends on the number of actors in its production<br />Actors reuse the same geometric rule when growing the environment<br />
  31. 31. Comparison to modern planning<br />The plan sets up a scale for the city<br />The developer decides the size of lots<br />The builder imports building plans from wherever<br />Inhabitants decide nothing at all<br />Result:<br />
  32. 32. Emergenturbanism<br />Rethink the role of the homeowner in house building<br />Rethink the role of the developer in subdivision<br />Rethink the role of public works in the network<br />Rethink movement entirely<br />
  33. 33. Shape grammars<br />Sell a building system instead of a building plan<br />
  34. 34. Subdivision<br />Lots are drawn and selected on the fly instead of being subdivided in advance<br />
  35. 35. The complex grid: village<br />
  36. 36. The complex grid: town<br />
  37. 37. The complex grid: city<br />
  38. 38. SharedSpace<br />De-signalize public space<br />Replace control withnegotiation<br />
  39. 39. Obstacles<br />Planning regulations<br />The permitting system<br />The banking and financial system<br />Political habit<br />
  40. 40. Fractal government<br />Government is affected by scale problems when the metropolitan scale is reached<br />Merging contiguous communities is not always a viable solution<br />Fractal scaling provides an interesting template<br />
  41. 41. Paris-Métropole<br />
  42. 42. Conclusion<br />Complexity means solving problems at every scale<br />Emergent geometric rules are necessary to create complex cities<br />Each aspect of the urban development process must be redesigned<br />
  43. 43. Thankyou<br />Thankyou for supportingEmergentUrbanism<br />Join the EmergentUrbanism Network<br /><br />Copyright Mathieu Hélie 2010<br />