Tag Archives: Wikipedia

The Cultivation of a Spontaneous City

This is the last of a series of excerpts from my article in the upcoming issue of the International Journal of Architectural Research, about the principles of emergent urbanism. Click here for part I, The Journey to Emergence. Click here for part II, The Fundamentals of Urban Complexity.

How emergent urbanism works

In a traditional spontaneous city, 100% of the surface is initially a network structure, open land. From this surface the best paths are selected to fit the networks that are emerging, and the leftover space is progressively built upon. Starting with a completely open, fully-connected land structure, the city’s design can consist of a purely negative process by placing constraints on construction over important paths. In this way the street structure and hierarchy becomes an evolved structure that matches the history of its networks, and the placement of buildings and uses is also an evolved structure that matches the flows of movement. Over time these paths are paved and upgraded, and important junctions of paths become the central open space of the city. The central square of a spontaneous town can be explained as the remainder of a fractal process of subtraction, with the most underused part of the spatial network being removed at each additional step of feedback until no further network subtractions are possible. With the circulation of people optimized, the remaining space is augmented with street furniture specifically designed for crowds, such as benches, transit stops, billboards, kiosks and so on.

An emergent city similarly begins with a network structure, although one that is much more sophisticated than open land. In modern design the typical asphalt street produces a network that is suited particularly to automobile networks, but also has the unfortunate side-effect of cutting pedestrian networks that normally enjoy the entire surface in a spontaneous city. As a remedy these streets are equipped with sidewalks that are often narrow and unpleasant (if not dangerous) to walk, an effort at translating strict traffic control methods to the pedestrian. It is not surprising that pedestrians are so rare in modern cities, but some efforts have shown that pedestrian networks can emerge from modern design. One example is the three-story deck of the La Défense business city in Paris (shown in figure 7), which contains parking but also regional rail and subway links, as well as being an open pedestrian surface. At the ends of this network structure a generative process of spontaneous development creates the actual networks of the city. As evidenced by the crowds present on that surface and the abundance of neighborhood shops the pedestrian networks function quite well. What is more surprising is that the automobile networks are underused and some parking structures empty, despite the neighborhood having been conceived for the automobile.

Figure 7

Figure 7. The “pedestrian slab” style of design was blamed for the failure of modernist urban planning projects, but at La Défense the slab is a working structure. The developer adopted spontaneous building development instead of applying the complete architectural plan, enabling the formation of a dense local economy.

Because of the high costs and other complexities involved in producing networks for modern transportation systems it is not possible to practice a purely negative and subtractive process of street formation. However the network structure must still be an evolved structure that is produced with feedback from lot development instead of building an entire grid before it has been decided what size of lot is needed. Most importantly all forms of movement must be in balance in the street design so that one type of network structure does not cut another and prevent the network formation process. (Salingaros, 1998)

The cultivation of a spontaneous city

Once a network structure is in place the process of network formation can begin.

Wiki systems have shown that simple freedom to create does not necessarily produce networks unless there also exists a simple interface to this network. The World Wide Web provided a system of linked websites that could spontaneously produce an encyclopedia for many years before the Wikipedia system catalyzed the distributed knowledge of millions of people into an exponentially growing and internally coherent system. The creation of crowd-catalyzing systems has since been named “crowdsourcing.” Translating crowdsourcing principles to planning processes, Alexander described in The Oregon Experiment how an institution could directly support the spontaneous development of its city by providing designers and managers to assist individuals and realize the program that the individual users have in mind. (Alexander, 1975)

With the initiative for developing new building programs left deliberately undefined and in the hands of the individuals and organizations that develop the socio-economic networks of the city, there remains the issue of producing a geometrically coherent landscape that is harmonious and distinctive. This is accomplished with shared generative processes, (Alexander, 2004) and particularly the nesting of generative processes into one another (also known as a shape grammar or form language), as shown in figure 8.  No matter what configurations of space are required by any individual building program, if this configuration is realized physically by the same building process as for any other random configuration then the two realized buildings will share symmetric properties and the result will be a harmonious geometric order. This has been employed in many instances by the regulation of construction materials, which creates a geometric order at the scale of texture, but it also applies for any other scale of geometry, as evidenced by the geometric order created by the advertisements in Times Square.

Figure 8

Figure 8. Three volumes are randomly defined in space without relation to each other. When a shared feedback function is applied to transform these volumes the volumes become related by these transformations. The function in this case is: 1 – Cut out the top corners to half the volume’s height, 2 – Raise the center of the roof.

By defining construction processes instead of fixed building designs it is possible to plan for future growth without eliminating spontaneous growth and feedback. A developer that is initiating a program of emergent urbanism can therefore prepare for construction in advance of any projects having been determined. Building high-technology structures is a complex art that requires significant expertise and a skilled workforce. The developer that creates adaptive building processes that can be used to generate and realize building plans easily and rapidly will provide the same spontaneity as squatter settlements achieve.

As evidenced by the popularity of historic towns of Europe and particularly the Mediterranean as tourist destinations there is enormous demand for and profit to be made from cities that adopt the geometry of emergent cities. For this to work however the development and banking industries must be persuaded of the effectiveness of process design as opposed to master planning, and the municipal authorities must be willing to approve urban design with no fixed configuration. (Alexander, 2004) Political issues also create a significant obstacle. The long approval processes that one must go through to develop a new city or neighborhood have significantly increased the length of the feedback loops and favored large-scale development as well as made small communities less competitive. Even when long review or public consultation processes can be avoided, a development has to comply with weighty subdivision and building codes that consume time to absorb and understand, and in so doing contribute to lengthening the feedback loops and making the urban tissue less adaptive and less sustainable.


Alexander, Christopher (1975). The Oregon Experiment, Oxford University Press, USA
Alexander, Christopher (2004). The Process of Creating Life, The Nature of Order Vol. 2, Center for Environmental Structure
Salingaros, Nikos (1998). ‘Theory of the Urban Web’, Journal of Urban Design, vol. 3, also in Chapter 1 of PRINCIPLES OF URBAN STRUCTURE, Techne Press, Amsterdam, Holland, 2005.

Creating the emergent dimension, or learning from Wikipedia

In Architecture: Choice or Fate, his manifesto for New Urbanism, classicist Leon Krier produced many inspirational images of urban complexity, going as far as a fractal comparison of modern and traditional buildings. The cover of the book, a fictional resort town for Tenerife, presents a fascinating case study of complex symmetry; no building is the same as another, but all share the same geometric properties. That would not be unusual had it not been an architectural manifesto. Competent artists have always been able to imagine dream cities, and they continue to do so with every blockbuster fantasy movie that hits the screens.

The dream city of Coruscant in Star Wars

The dream city of Not London in The Golden Compass

Like the dream cities of Le Corbusier and his modernist colleagues, the dream cities of artists have in common the fact that none of them have ever been realized. Leon Krier’s dream city, Poundbury, has been realized by the capital backing of a supernaturally rich patron, and even then it has been built very slowly and carefully. In the time it has taken to develop Poundbury, millions of urbanisations have occurred elsewhere. Like the New Urbanist TNDs of America, no matter how much we enjoy their architectural quality, we cannot consider them to be real cities. The real city has been built in the emergent dimension, not by the mind of a single artist but by the material necessities of all people. While it is fairly straightforward for an artist like Leon Krier to invent and apply his own form language to imagine a complex cityscape, in order for this design to be adapted to the material necessities of millions it must also involve millions. We obviously cannot burden a single artist with this task.

And so urbanism has a wholly different starting point from architecture. The artist does not have control. No one can possibly ever have control. Everything is happening all at once everywhere at once. To attempt to stabilize this process has caused chaos everywhere.

The starting point of urbanism is the same starting point that the founder of Wikipedia, Jimmy Wales, set for himself when he established the Internet’s now most indispensable website. Instead of asking how to publish the expert opinion of specialists as an encyclopedia that would compete with the print powerhouses (a venture he had already attempted and failed at), Wales based his system on the theories of economist and complexity scientist Friedrich von Hayek. The idea that Hayek proposes is that there exists specific knowledge that only individuals possess, and that can only be utilized with their cooperation. Wales saw his task as the aggregation of this knowledge into one coherent system.

The world-wide-web had, since the early 90’s, become a massively hyperlinked knowledge network that everyone could publish in. The reality at the time of Wikipedia’s creation was that this power had not produced any kind of coherent system for basic knowledge. Aggregating knowledge had up to then been too complicated. Wales wanted, in his own words, to “make the Internet not suck.” Overcoming this deficiency meant simplifying the production of web pages and hyperlinks, removing some unnecessary choices in the process. This is what the interface of Wikipedia did. Within a year, Wikipedia had grown explosively and exponentially. Making information easier to create and access had made it possible for the sum total of encyclopedic knowledge to be rapidly constituted.

This has come at a cost, however. While there is in theory unlimited freedom to add content that one considers relevant to Wikipedia, the form that this content will take on screen is very rigidly defined. This is necessary in order to achieve the complexity of the system. The design of Wikipedia is constant across every page in order to make it possible to rapidly navigate through all the information without having to relearn the rules for every article. Nevertheless, when we click on a link to a Wikipedia page, we never know what we are going to get. The design acts not as a constraint on the content, but as an enabler of the content. Without the rules enforced by Wikipedia, none of the content would have been added.

Wales and his foundation have been extremely controversial. On the one hand, in order for Wikipedia to work as it does, the foundation must provide all the support structures necessary to enable the users to create knowledge, and on the other hand it must also blindly trust the users to create information that will be accurate. It simply is not possible to control the content of so many millions of articles. To attempt this would necessarily shrink the size and reduce the complexity of the system, destroying what makes Wikipedia useful in the first place. The emergent dimension must either be embraced or rejected.

The lessons learned from Wikipedia can also be learned from the very rich past of urban planning. Historically the most successful cities have not been those who have had the least planning but the most enabling plans. The Manhattan plan of 1811, for example, provided for the flexible extension of a street grid without interfering in what could be built within the blocks, and so enabled a surge in urbanisation that was unmatched in history. Eventually this model reached its complexity limits and a new design for Manhattan was applied (with varying success), such as the building codes that gave us wedding-cake skyscrapers, and the metropolitan transit system of subways and later on expressways.

The darker side of this phenomenon has been the creation of city designs that inadvertently enabled the creation of a type of city that no one wanted. Every city, no matter how loudly the local authorities claim to be planning-free, have a design. Take the classical example of a “no planning” city, Houston. Although it has no zoning codes, Houston has a system for laying down a grid of roads that implies necessarily a large-scale, long-ride, automobile-dependent city. By their very form, these roads make some types of urbanisation easier and others more difficult. Who is going to build for a walkable neighborhood when there are no sidewalks? How can a TND make a walkable city when at every mile a thoroughfare cuts off the pedestrian links? How can a sustainable city emerge when only one form of link, long-range auto trips, can be made between destinations?

The threat that we face today is not suburban sprawl. New Urbanism and Smart Growth have been victorious in that aspect. The danger we face is dense sprawl, (see Eric Eidlin, The Worst of All Worlds Los Angeles and the Emerging Reality of Dense Sprawl) where our disconnected cities become denser and denser without becoming more complex, resulting in even poorer urban conditions. The suburb is not the design. Sprawl is the design.

Our cities may not be what we wanted, but they have not been accidents. They are the result of designs applied by the local (and sometimes not-so-local) authorities. They will only change if we invent and apply new designs for them. They cannot be architectural designs founded upon control of the artist. They also cannot be the endless grid of highway strips. Yet they must have both art and highways. It is a whole new method of design, emergent design, that we must master.


Wikipedia and Beyond: Jimmy Wales’ sprawling vision