Tag Archives: emergence

The Journey to Emergence

This is part I of a series of excerpts of an article to be published in the International Journal of Architectural Research entitled The Principles of Emergent Urbanism. Additional parts will be posted on this blog with the editor’s permission until the complete article appears exclusively in the journal’s upcoming issue.

Of the different domains of design urban design is an oddity. While the design of a machine can be traced to a definite, deliberate act of invention, and even the design of buildings (architecture) is rooted in known production processes, the design of cities was never seriously attempted until well after cities had become a normal, ordinary aspect of civilized living, and while the design of machines and buildings was a conscious effort to solve a particular problem or set of problems, cities appeared in the landscape spontaneously and without conscious effort. This places the efficacy of urban design in doubt. The designers of machines and buildings know fully how the processes that realize their design operate, and this knowledge allows them to predictably conceive the form they are designing. Urban designers do not enjoy such a certainty.

How is it possible for what is obviously a human artifact to arise as if by an act of nature? The theory of a spontaneous order provides an explanation. According to Friedrich A. von Hayek (Hayek, 1973) a spontaneous order arises when multiple actors spontaneously adopt a set of actions that provides them with a competitive advantage, and this behavior creates a pattern that is self-sustaining, attracting more actors and growing the pattern. This takes place without any of the actors being conscious of the creation of this pattern at an individual level. The spontaneous order is a by-product of individuals acting in pursuit of some other end.

In this way cities appear as agglomerations of individually initiated buildings along natural paths of movement, which originally do not require any act of production as dirt paths suffice. As the construction of individual buildings continues the most intensely used natural paths of movement acquire an importance that makes them unbuildable and these paths eventually form the familiar “organic” pattern of streets seen in medieval cities. This process still takes place today in areas where government is weak or dysfunctional, notably in Africa where urban planning often consists of catching up to spontaneous settlement, and in the infamous squatter slums that have proliferated in the 20th century.

transect-of-tultepec

A transect of the city of Tultepec in Mexico provides a snapshot of the different phases of spontaneous urban growth. (Google Earth image)

As urbanization becomes denser, the increasing proximity of concurrent, competing individual interests causes conflicts between the inhabitants of the emerging town. Individuals build out their properties in such a way that it interferes with others, for example by blocking paths or views. These acts threaten the sustainability of the spontaneous order, and to resolve this situation the parties involved appeal to the same judges that rule on matters of justice. These judges, again according to Hayek, are required to restore and preserve the spontaneous order with their rulings. These rulings provide the first building regulations and, when government authority becomes powerful enough to do so, are compiled into comprehensive building codes to be applied wherever the force of that government extends. (Hakim, 2001)

The compiled building codes are later brought by colonists to create new settlements, reproducing the morphology across multiple towns but each time in a pattern that is adapted to the local context. Early town planning efforts are attempts at regularizing the building codes in order to plan for long-term organization of cities, but maintain the spontaneous production process. Most notably the rapid urbanization of New York City was accomplished by very simple rules on the size of blocks laid out in the 1811 Commissioners Plan for New York. Unlike the experience of urbanization in previous centuries, where urban growth was slow and often stagnant, the urbanization of New York took place in a time of rapid social and economic changes, and the city government had to invent building codes involving issues that never could arise in a pre-capitalist society: first the tenement, then the skyscraper, and ultimately, the automobile.

Modernism: the replacement for the spontaneous order

Architects and urban planners of the early 20th century, confident in the techniques of engineering and industrial production, believed that the spontaneous city had become irrational and had to be replaced with a new design fully integrating new industrial technology. The Swiss architect Le Corbusier is famous for designing a complete city around the automobile and building models of his design. In so doing he adopted a process of urbanization that was completely planned hierarchically, applying the processes familiar to architects at the scale of an entire city. He also ridiculed the morphology of spontaneous cities as being the product of donkey-paths.

villa-radieuse

This scale model of Le Corbusier’s Plan Voisin marks the turning point where city plans as constraints on individual initiative are replaced with architectural design at the scale of millions of inhabitants. (Le Corbusier, 1964)

Although the architectural program of high-rise living of Le Corbusier was discovered to be a colossal failure, the modernist process of development replaced spontaneous urbanization in the industrialized world. The housing subdivision substituted adequately for the high-rise tower block, providing affordable housing in large numbers to a war-impoverished society. This production process is still in force today, separating cities into three distinct zones: residential subdivisions, industrial and office parks, and commercial strips.

Modern city planning has been successful at its stated objective, producing a city designed specifically around automobile use, yet it was immediately and has been perpetually the target of criticisms. Most significantly the vocabulary of these criticisms had to be invented in order to spell out the critics’ thoughts because the type of deficiency they were observing had never been seen. Words like placeless or cookie-cutter were invoked but fell on the deaf ears of urban planners who were trained in Cartesian processes and industrial production techniques.

The most devastating criticism of modernist urban planning came in the form of a sociological study and personal defense of the spontaneous city, the book Death and Life of Great American Cities by Jane Jacobs. (Jacobs, 1961) In it she described in great details how the functions of a spontaneous city related and supported each other. Her concluding chapter, the kind of problem a city is, is still the most relevant. In it she attacks the scientific foundations of urban planning at a paradigmatic level, and claims that the methodology of the life sciences, at the time undergoing the revolution created by the discovery of DNA, is the correct approach to studying cities.

Death and Life of Great American Cities has been adopted by contemporary urban planners as a textbook for urbanity. Its descriptions of the characteristics of a city are now the models upon which new developments are planned. The old urban development of housing subdivisions and office parks is being substituted for the new urban development that has streets, blocks, and mixed uses, just as Jacobs had described to be characteristic of life in the city. A major difference between Jane Jacobs’ preferred city and the new urban plans remains. The layout of mixed uses is organized and planned in the same process as Le Corbusier planned his city designs. The scientific suggestions of Jacobs have been ignored.

The discovery of emergence and complexity science

In the time since Jacobs published her attack on planning science molecular biology has made great technological achievements and provided countless insights into the morphology of life. In parallel the computer revolution has transformed the technology of every human activity, including that of design. But the computer revolution brought along some paradigm-altering discoveries along with its powerful technology. In geometry, the sudden abundance of computing power made it possible for Benoit Mandelbrot to investigate recursive functions and his discovery, fractal geometry, generated a universe of patterns that occurred in many aspects of the physical universe as well as living organisms. (Mandelbrot, 1986)

Some thinkers saw that the life sciences were part of a much more general scientific domain. They formed the Santa Fe Institute and under the label complexity studied not only organisms but also groups of organisms, weather systems, abstract computational systems and social systems. This research formed a body of theory called complexity science that has resulted in the creation of similar research institutes in many other places, including some centers dedicated specifically to urban complexity.

Their scientific revolution culminated in two major treatises within the last decade, both from physicists practicing in a field of complexity. The first was A New Kind of Science by computer scientist and mathematician Stephen Wolfram (Wolfram, 2002), where he presents an alternative scientific method necessary to explore the type of processes that traditional science has failed to explain, presenting a theory of the universe as a computational rule system instead of a mathematical system. The second was The Nature of Order (Alexander, 2004) by architect Christopher Alexander, where he presents a theory of morphogenesis for both natural physical phenomena and human productions.

A definition of emergence

To define what is meant by emergence we will use the abstract computational system upon which Wolfram bases his theories, the cellular automaton. Each cell in a row is an actor, making a decision on its next action based on its state and the states of its direct neighbors (its context). All cells share the same rule set to determine how to do this, that is to say all cells will act the same way with the same context. In this way each row is the product of the actions of the cells in a previous row, forming a feedback loop. The patterns of these rows are not in themselves interesting, but when collected in a sequence and displayed as a two-dimensional matrix, they develop complex structures in this dimension.

rule30

The 30th rule of all possible rules of one-dimensional cellular automata produces a chaotic fractal when displayed as a two-dimensional matrix, but most other rules do not create complex two-dimensional structures. The first line of the matrix is a single cell that multiplies into three cells in the second line in accordance with the transformation rules pictured below the matrix. This process is reiterated for the change from the second to the third line, and so on. All the information necessary to create structures of this complexity is contained within the rules and the matrix-generating process. (Wolfram, 2002)

The same general principle underlies all other emergent processes. In a biological organism a single cell multiplies into exponentially greater number of cells that share the same DNA rules. These cells create structures in a higher dimension, tissues and organs, which form the entire organism. In the insect world complex nests such as termite colonies emerge from the instinctual behavior of individual termites. And in urbanization, buildings form into shopping streets, industrial quarters and residential neighborhoods, themselves overlapping into a single whole system, the city.

References

Alexander, Christopher (2004). ‘The Process of Creating Life’, The Nature of Order Vol. 2, Center for Environmental Structure
Corbusier, Le (1964). La Ville Radieuse. Éléments d’une doctrine d’urbanisme pour l’équipement de la civilisation machiniste, Édition Vincent Fréal et Cie, Paris, France
Hakim, Besim (2001). ‘Julian of Ascalon’s Treatise of Construction and Design Rules from Sixth-Century Palestine,’ Journal of the Society of Architectural Historian, vol. 60 no. 1
Hayek, Friedrich A. (1973). ‘Rules and Order’, Law, Legislation and Liberty Vol. 1, Routledge and Kegan Paul, London and Henley, UK
Jacobs, J. (1961). The Death and Life of Great American Cities, Random House and Vintage Books, New York, USA
Mandelbrot, Benoit (1986). The Fractal Geometry of Nature, W.H. Freeman, New York, USA
Wolfram, Stephen (2002). A New Kind of Science, Wolfram Media, USA

Squaring the circle

tultepec

Natural paths of movement emerge through gaps in the blocks imposed by a municipal grid in the town of Tultepec, Mexico. These paths show how the street configuration of medieval cities comes to be defined. The urbanized gradient between the center of town and its outskirts shows the different stages in the emergence of a fully natural town.

For those with strong stomachs, scroll to the south to see some truly horrific modern housing blocks.

The complex grid

In a medieval-era city the pace of urban growth is slow to a point where the growth of the city is not consciously noticed. Buildings are added sporadically, in random shape and order, as the extremely scarce economic situation makes no other pattern possible. Typically this means that the shape of streets will match the existing natural paths of movement, giving the street network an organic structure that is preserved through successive transformations in the urban fabric.

This works until the street network becomes large enough to become a functional problem. Because it is random, the medieval street network becomes complicated to move around in once the structure exceeds a certain scale. Some people see this as an obstacle to commerce and project to restructure the emergent medieval grid into something more rational. These projects fail for the same economic reasons that shaped the emergence of the medieval streets.

As the pace of urban growth increases and as the cartesian paradigm expands in the 17th and 18th centuries, deliberate city planning through the pre-emptive definition of an urban grid becomes fashionable. The practice of baroque planning remains the privilege of ultra-rich landlords considering the scale of construction involved. (Louis XIV’s Versailles is still the case study.) In the Americas such concentrations of capital do not yet exist. Grids are not truly part of a city plan, they are the outcome of regulations meant to avoid the pitfalls of medieval urban growth. Although the idea of a block is defined, the limiting shape of the grid itself is undefined. This allows cities to grow out, in theory, infinitely.

This works until the grid encounters and existing structure in the landscape. While Europe’s land is already very complex, in America the land is mostly empty. One exception is New York, which has multiple grids expanding towards the center of Manhattan, all with their own alignment with the waterfront. Compounding the medieval streets below Wall Street, the city’s network is getting messy. The solution conceived is the first city plan of New York, the Commissioners’ Plan of 1811, which grids Manhattan in the pattern it is famous for to this day with the help of a concentrated political power. In Europe this much centralization is not available, cities being ringed by a large number of villages that already structure the land. One notable exception is Barcelona, which under conservative military domination had reserved a large non aedificandi zone outside of its defensive walls. With the military out of the picture, and the industrial revolution putting enormous pressure on the city’s growth, the next most famous cartesian grid plan is imposed: the eixample. Adepts of the medieval city such as Camillo Sitte praise its artistic value and quality of life, but fail to truly describe how to reproduce it in the context of accelerating urbanization.

The 19th century is the triumph of the cartesian plan. It is not only employed to plan cities but to plan the entire American landscape. West of the original colonies the map becomes rectilinear. The flexibility and fluidity of New York’s grid plan promotes very rapid land development and the city achieves growth rates never before seen. European city planners are facing the same growth pressure but are trapped by the land’s existing structure, both physical and political. One simple solution is discovered: demolishing city walls and building a high capacity road that encircles the city, the boulevard. If it is to be complicated to get inside a city, it will at least be simple to get around it. Paris builds two on its two successive walls, and Vienna builds the famous Ringstrasse. An interesting phenomenon emerges from subsequent growth. While the boulevards were meant to be restful promenades, they emerge to become important centers on their own due to their attractiveness for traffic. In space syntax terms, they are integrators.

Manhattan’s grid extends to over a hundred streets but starts to suffer from severe scale problems. The medieval street system drives traffic away to boulevards, but in an endless grid traffic goes everywhere, and there is no place that is free of the increasing congestion. With the introduction of the car the endless grid is in crisis. Since no better idea is found, the grid system is replaced with the high-capacity collector road to concentrate all the congestion, from which huge, isolated developments  access each other. This is the suburban sprawl system that remains the norm. It has the advantages of being simple to plan and giving enormous clout to land developers. However people are dissatisfied with the enormous scale of their environment. That they enjoy a single-family home does not sufficiently conceal the fact that they are clustered with thousands of similar homes, and next to those are huge strip malls, office parks and shopping malls that require long vehicle trips to access. The disconnect between their homes and their activities means they live in a form of crowded isolation. The suburbanites escaped congestion only to arrive at emptiness. There is more life in the less populated countryside. Adepts of the metropolitan grid such as Rem Koolhaas praise the culture of congestion as a lifestyle that the collector road fails to create.

This was as briefly stated as I could the modern history of the urban network: one system failing to adapt to the scale of the city, being replaced by a larger system that erases the small scale complexity of the previous only to itself fail at a much larger scale, and then another larger system crushing all complexity to resolve a problem of modernity.

Is there a way that we could have the benefits of all systems balanced as a whole urban network? To describe such a system, we can first define some proscriptions.

  • Any size of urban growth is allowed as long as the new growth extends the boundary of the network. This ensures that the city has the economic flexibility of the medieval city and allows anyone, no matter their economic importance, to contribute to the city’s growth.
  • The network must not become so complicated that it becomes impossible to move around in order to participate in large-scale activities and a culture of congestion.
  • Streets must not grow too long without interruption in such a way that speeding and traffic accidents are encouraged.

How does this work out in terms of prescriptions? It turns out to be very simple. If we assume that we start with a hamlet of a single block, or a regional road that is undeveloped, we need only two rules: one for private development and one for the community.

  • For private development: you may build on any available part of the network so long as you replace the part you used up by extending the network around your new block.
  • For community development: any time a part of the network becomes too complicated (for example it takes more than 4 steps to get out of a sector), extend the boundary of that part with a higher capacity road (a boulevard).

How do we tell if these two rules really do meet the proscriptions we defined? Since we’re talking about an emergent design, the only way to see how it works is to do an explicit simulation of the computations involved. For this I employed a Fibonacci sequence to stand for a random growth process. With each new block that the sequence generated, I placed it in the section of the network that minimized the private cost of extending the boundary. I also used square blocks to simplify the computations involved, and also to demonstrate how such a process would work in a structure of land that has been made square, for better of worse, through cartesian planning. The process would work just as well in a more fluid, rounder land structure such as exists in Europe and the American East.

Stage 1: The village

complex-grid-village

The village is a cluster of houses and small businesses, whose only real challenge is maintaining a facade with the outside by ensuring that every new block also fronts the countryside. This provides the village with a path that everyone can walk around on whenever they want to get some fresh air and open space.

Stage 2: The town

complex-grid-town

The town starts to support development at larger scales with bigger block sizes. The first boulevards are built around the original village, preserving its traditional atmosphere from the growing businesses on the new boulevards.

Stage 3: The city

complex-grid-city

Now a significant regional center, the city’s economic complexity is heralded by the construction of the ring road enclosing the town’s neighborhoods. Large developments such as a regional shopping mall, an airport and a TND line the ring road alongside other smaller blocks of more traditional housing and business that take advantage of the high centrality of the ring and its new culture of congestion, eventually forming whole neighborhoods of their own. The ring road also encloses available green spaces for recreation, making it a parkway in some segments.

Emergent properties of the process

The most interesting outcome is that the structure of the network makes a very nice chaotic fractal, showing the balance between scales in the city’s growth. It is simultaneously simple to grasp and complex, living geometry.

complex-grid-fractal

The spatial integration created by the boulevards and ring roads also promotes the creation of a hierarchy of different centers that are evenly distributed between neighborhoods. Tightly knit residential quarters provide security for children and the elderly, with neighborhood centers within walking distance and no threat of heavy traffic until the edge of the city, liberating citizens from automobile dependency.

Adopting a complex grid is going to benefit small towns and villages most, as their economy is typically not large enough to support the collector road system. It might even result in the emergence of new villages in rural regions that have experienced large-scale urbanization and thus make them more resilient to economic shocks.

For existing cities, history provides a precedent for increasing the grid’s complexity when the problem is scaling up the grid. The urban renovations of Haussmann in Paris or Robert Moses in New York showed how to compose a larger scale within an existing city. (In Moses’ case, how not to do so as well.) However there is no precedent for scaling down a network that is too big, which is what modern cities suffer from. I suspect that contrary to scaling up which requires a strong centralization of power, scaling down involves a decentralization and a multiplicity of new powers transforming neighborhoods, breaking up regional, municipal and even neighborhood authorities such as homeowners’ associations to create local economies.

Chaos re-emerges

1960’s psychedelic art?

landscape-chaos

Or the American landscape?

Notice how much negative space is created by the imposition of the grid on a chaotic reality. The simplicity of the cartesian plan is deceptive. It generates complications as the random process of change unfolds.

Decoding paradise – the emergent form of Mediterranean towns

scarano4

Serifos in Greece

Until very recent times, a study entitled Julian of Ascalon’s Treatise of Design and Construction Rules From Sixth-Century Palestine might have been categorized somewhere in-between ancient history and archeology of architecture, if not relegated to the dusty shelves of legal scholarship. Although it deals with one of the most sought-after secrets of architecture, how to build the charming Mediterranean towns of Greece, Spain, North Africa, the Near East and many other places, this is not immediately obvious from the content of the treatise. The reason for this is that the treatise does not so much describe the form of the town as the process for building it, and the process turns out to be emergent. Unless the reader makes the link from process to form, the rules described will make no more sense than the rules for a cellular automaton out of context.

It is tragic that enormous amounts of resources have been spent attempting to recreate the Mediterranean town with no clue as to the underlying source of its complexity. Montreal itself has the world famous Habitat 67, a confusing pastiche of the memories that architect Moshe Safdie brought back from his land of birth, which he had in common with Julian of Ascalon. Habitat 67 was intended to be a low-cost solution to housing, but it never was taken seriously as a model for urban habitat, and its current untrendiness spares it from being labeled fake complexity. That an attempt to emulate the architecture of some of the poorest people of previous centuries would result in an expensive failure testifies to the inadequacy of modern production processes, but also of the wealth inherent in those simple traditional production processes. The beauty resulting from large aggregations of simple buildings has turned many towns into tourist destinations. There is value in process.

The complexity demonstrated by the constructions of pre-modern civilizations may be a direct consequence of their material poverty. Most people will claim that the loss of building quality is a result of culture, and so we must change our own culture through education. That is not a complete answer. Cultures are stored in information technologies and media. The modern era coincides with the invention of printing, making it possible for the first time to reproduce information in large quantities at low costs. As information technologies have progressed and become more affordable, building processes have become increasingly dependent on large amounts of descriptive information, with blueprints describing in every minute detail how to compose a building. And now that CAD software can describe and store nearly limitless information, whole new forms of buildings have become possible.

All of this progress has only enabled builders to become lazier with information. Pre-modern builders, limited to oral communication and their brains to hold information, had to employ very sophisticated means of information compression to communicate and simply remember their cultures. This lead them to rely on simple processes the likes of which are behind the complexity in fractal geometry and cellular automata to build their environments – very short sequences of information that can be utilized to generate fully complex forms. Christopher Alexander even used as an example, in The Nature of Order, the production of a boat that had been coded into a song that the builders recited while creating the boat, adding a mnemotechnical aspect to the storage of cultural information that was essential to pre-modern survival.

Without knowing how traditional cultures were stored, we had no idea how to inspire ourselves from them. Modern and post-modern architects attempted in vain to imitate traditional building using their own, lazy information technologies, and succeeded only in building pastiche of complexity. The breakthroughs in complexity theory of the past decades finally gave us the opportunity to decode the mysteries of historic building cultures by showing us what kind of information to search for. What was right in front our noses suddenly becomes deeply meaningful.

It is to his great credit that Besim S. Hakim went looking specifically for the source of the emergent forms of Mediterranean towns in treatises of building laws. From his study of the treatise of Julian of Ascalon, but also of those of Muslim scholars around the Mediterranean, he was able to identify the underlying process that generates the complex morphology all towns of the region have in common, and that so many have sought to imitate. It is no exaggeration to call this pioneering work in complexity.

The space of Hakim’s search began in the Islamic world, with the treatise of Ibn al-Rami from Tunis in circa 1350. Tracing the origins of the practices described in the treatise, references to treatises written in Egypt, Arabia, Tunisia and Andalusia in previous centuries were researched until the treatise of Julian of Ascalon was uncovered. Written in Palestine to describe the local building customs in order to provide the Byzantine empire with an improved legal system, this particular treatise’s value is its longevity. After propagating throughout Greek civilization as part of a general book of laws (the Hexabiblos), its authority was invoked in decisions dating as recently as the 19th century. Hakim infers the origins of these shared practices, and the shared morphology of regions as far apart culturally, linguistically and geographically, as Andalusia, Greece and Palestine, to customs from ancient Babylonian civilization that had spread to the Eastern Roman Empire.

The goal shared by these treatises is a definition of urbanism as relevant today as it was in Babylon:

The goal is to deal with change in the built environment by ensuring that minimum damage occurs to preexisting structures and their owners, through stipulating fairness in the distribution of rights and responsibilities among various parties, particularly those who are proximate to each other. This ultimately will ensure the equitable equilibrium of the built environment during the process of change and growth. (Hakim, Mediterranean urban and building codes: origins, content, impact, and lessons, p. 24)

Here we see what the underlying error of Habitat 67 was. It was designed as a single static building imitating a process that made a living tissue out of many individual acts of simple building. The codes of the Mediterranean treat the town as a living, whole structure in movement that must be preserved while it achieves equilibrium with a changing environment and society.

Perhaps the most relevant conclusion of this research is the identification of proscriptive and prescriptive rules for building.

Proscription is an imposed restraint synonymous with prohibition as in ‘Thou shalt not’, for example, you are free to design and manipulate your property provided you do not create damage on adjacent properties. Prescription is laying down of authoritative directions as in ‘Thou shalt’, for example, you shall setback from your front boundary by (x) meters, and from your side boundaries by (y) meters regardless of site conditions. Byzantine codes in many instances included specific numeric prescriptions, unlike their Islamic counterparts that tended not to include them. (Hakim, Mediterranean urban and building codes: origins, content, impact, and lessons, p. 26)

A prescription would be a rule that defines in detail what to do in a given situation. A proscription is a template for defining prescriptive rules, a pattern for a rule. Muslim scholars provided mainly proscriptions, but Julian of Ascalon’s treatise was highly prescriptive. Julian was describing in details the local building codes with the idea that they would be used to devise proscriptive rules for the empire. By accident these prescriptive rules became law and remained in force for centuries until their inability to deal with society or physical conditions radically different from sixth century Palestine made them obsolete. Although it means the codes failed to deal with changing circumstances, this gives us the chance to bridge the gap between the physical structure of built towns and the rules that generate them.

The concept of proscriptive rules also helps explain why so many different cultures with specific structural typologies can generate such similar morphology. Hakim uses as an example the problem of views. The Greeks were preoccupied with views of the sea, and their prescriptive rules obliged the preservation of view corridors in new constructions. Muslims, on the other hand, were preoccupied with the preservation of privacy and the prevention of intrusive views from one property to another. This would have very different results structurally, however those two prescriptive rules are based on the same underlying proscription. Local customs and culture could therefore be translated into prescriptive rules using the proscriptions inscribed in building treatises and the emergent morphology of those proscriptions would be symmetric from one culture to the next, while being fully adapted to local conditions.

Another significant fact that strikes out from these treatises is the importance of relationships between neighbors. The Julian of Ascalon treatise describes how to literally embed houses into each other, ultimately making them one continuous, somewhat random building created through iterated steps. But most importantly by proscribing rules as relevant to a neighborhood, Mediterranean urbanism avoids the problem of the absolutist, dare I say “Cartesian” rules of modern planning that are relative to the precisely subdivided lot the building is on. Hakim shows the wastefulness of latter rules in a comparison of the old town of Muharraq in Bahrain with a new subdivision from modern Muharraq.

hakim1a hakim1b

The town on the left was generated using proscriptions based on neighbors, while the subdivision on the right used absolute rules planned with the subdivision. Notice that the configurations on the right waste much of the space in order to achieve a strictly Cartesian, grid-like morphology that no doubt looks orderly to the planners.

The last item of significance, and perhaps the most revolutionary, is how the proscriptions extracted by Hakim are similar in nature to the rules that Stephen Wolfram described to generate emergent complexity with cellular automata. He himself follows a proscription/prescription system, where the proscription is for example the 2 color, one-dimension elementary cellular automaton that made him famous, for which there exist 256 different prescriptive rules of neighborhood, some of which grow in time to make two-dimensional chaotic fractals. Some urban complexity researchers such as Michael Batty have been playing with cellular automata trying to reproduce urban form, but their efforts have taken them on the wrong track. The codes of historic towns behave in the same manner as a cellular automaton. This should be the focus of their research.

Whatever the potential for research, the proscriptions discovered by Besim S. Hakim are still relevant today and can be used to create the prescriptions that we need to implement an emergent urbanism relevant to the problems of today, that is to say the creation of a sustainable city and living urban tissue out of the vast urban fabric of suburban sprawl. Hakim has so far focused his work on the regeneration of historic neighborhoods by restoring the generative codes that produced them, but there is a vast potential to expand his work to non-historic neighborhoods that are in dire need of new life.

Addendum

Four regions, four cultures, one shared process generating a symmetric morphology

sidibousaid

Tunisia

mojacar-from-the-air

Andalusia

scarano1a

Greece

palestine

Palestine

Reference

Besim S. Hakim – Generative processes for revitalising historic towns or heritage districts

Besim S. Hakim – Julian of Ascalon’s Treatise of Construction and Design Rules from Sixth Century Palestine

Besim S. Hakim – Mediterranean urban and building codes: origins, content, impact, and lessons

and don’t forget to look at Besim S. Hakim’s website.

Mr. Besim S. Hakim provided comments for this article

Picture from Alessandra Scarano were also used

Producing land with nested markets

The Poundbury Grid, from Streets and Patterns by Stephen Marshall

The Poundbury Grid, from Streets and Patterns by Stephen Marshall

When the modernists unleashed their program for simplifying cities, they did not limit themselves to redirecting existing institutions. Within the modernist ideology was implied the idea that transportation, open space and buildings were separate, isolated things and could therefore be made in isolation. This lead them to create entirely new institutions that operated independently. One of these was the Department of Transportation, also called Ministry of Transportation, or Délégation Départementale de l’Équipement, or somesuch. Its mission was clear: build roads, make them fast, clear away all obstacles and let’s drive. While the collapse of the modernist program in architecture swept away the building typologies they had invented and would later make room for the creation of such architectural artifacts as Poundbury, the transportation system they had devised continues to operate unchallenged. This system, it must be realized, is sprawl. It is the engine of urbanisation throughout the world. It does this by taking rural land and upgrading it, without any conscious realization of what it is doing, into urban land. The very existence of Poundbury, or any other New Urbanist development, is owed to this urbanization. Without it, it could not have any economy. It is therefore incorrect to refer to it as only a transportation system. It is a land production system, creating markets for land where there were none before.

Writer Alex Marshall (not Stephen) correctly diagnosed what was occurring in How Cities Work. In it, he identified the architects and planners of economic powerhouse Silicon Valley as being the state and federal transportation agencies, and invited New Urbanists to work for these agencies if they wanted to have an effective impact on the design of cities. While his book is an illuminating exploration of the processes for building cities and even lays the groundwork for an emergent theory of urbanism, by the middle chapters Alex Marshall seems to lose his mind and lays the blame for the urban mess on market ideology, Republicans and the almighty Libertarians. If only government authority over land was unrestricted, and the voters (I presume) realized that an urban planning system is a choice and not an inevitability, then once again real cities could be made instead of sprawl.

I appreciate his arguments in favor of making better, more informed, richer choices in how cities are planned. But the fact that the tone of his book radically shifts from cool, rational analysis about systems for urbanisation to anger and blame over restrictions imposed on government authority shows that he has disentangled one layer of confusion about cities only to expose another, even more entangled layer: that of land ownership and market creation. To see through that layer requires traveling back in history to the very beginning of the industrial age and farther.

Our ancestors in America lived almost exclusively as homesteaders and independent land owners. The appeal of migrating to the new world was the abundance of homesteadable land. At the beginning of the 19th century, places such as New York City were shipping towns of little importance relative to the agrarian economy. This was not the case in Europe, where the land was owned in very large estates by a small number of aristocratic families. The rest of the population lived upon the land as tenants. Cities also were estates, with those not owned by the aristocracy being owned either by the clergy or by corporations of merchants chartered in the middle ages. (The City of London somehow miraculously continues to operate by this system.)

The fact that Europeans and Americans had a vastly different starting point in land ownership affects the way they conceive of municipal authority. Because land estates always regulated tenants and built improvements such as roads to collect rents, Europeans will see the city as a public service and consider zoning and regulation as completely normal and legitimate. In America every man was his own land owner. Land rents, roads and zoning were imposed through the force of government upon those small land owners. Because of this, Americans see the city as a government interference and resist zoning and regulation.

The suburban dream, to own one’s house, has come to replace the American dream, to own one’s land. But the economic reality of owning a parcel of land and being a landowner are completely different. Our ancestors lived from their land, not simply on it. Their wealth came from their land. A house owner simply resides on his property, he does not live from it. His living is made from his participation in the life of the city, and he needs the roads in order to do that. Should the road to his house be blocked off, either intentionally or by natural accident, the house would become useless but he would not lose his living. A house owner is as much a tenant as his European ancestor. He rents the streets he lives from.

The relationship between transportation and land rents has been known forever. In the late 19th century railroad developers created new neighborhoods of cities by buying up isolated land, extending the railroad to it and then parcellating it into lots. The people of this new neighborhood lived from the railroad commute. The development of Los Angeles is famous for having been driven by streetcar companies expanding to new areas and profiting from the land they improved. The ownership of the streets was then transferred back to city corporations. It was moved from private to communal ownership, with all the pitfalls this implied.

Seeking to increase the value of their developments by adding a more restrictive layer of controls over the subdivisions they produce, developers have for the last few decades been creating home owners’ associations to provide for the roads and control covenants upon the private parcels of home owners. In doing so they have chosen to take an alternative course to municipal incorporation, but unfortunately the organizations have shown themselves to be draconian in their application of rules as banal as the height of lawns and in so doing compounded the reputation of suburban subdivisions as zones of conformity. The HOA is a cooperative ownership model that transforms subdivisions into structures as rigid as a condominium tower, without the material rigidity of the tower itself. If one is an advocate of the suburban subdivision in the name of freedom, this model seems to miss the mark.

It is indisputable that HOAs provide a good, environmental control, that home buyers wish to have. They are willing to give up control over their house in exchange for part control over the neighborhood. The developers are creating neighborhood value by tying their product into a system of rules, and in doing so increasing the demand for the individual homes. Developers are creating rules-constrained markets within the framework of the HOA, a cooperative of home owners who pay a rent to have the right to be part of this market. The HOA market itself exists within the market created by the road that integrates it to the productive economy, road which has almost certainly been created by a municipality or county administration. It is a market within a market, and both have their specific rules as to how land may be utilized.

Alex Marshall claims that market creation is the exclusive domain of government. I believe this is dangerously incorrect, not out of anti-government bias but because the organization of government places strict limits on the complexity of the markets that will be created, something that we both appear to agree is a major flaw of our urbanism. To show this, I will explain the history of one of the weirdest cities of Paris, the business district La Défense.

almost-utopia gare-grande-arche noeud-gordien-ii

The most peculiar aspect of the city is its organization of land. It was founded in the late 1950’s and planned in the early 60’s in the model of utopian modernism, which meant strict separation of pedestrian and vehicular traffic and rows of identical tower blocks. The master plan rapidly fell apart and was abandoned when it was realized that the companies for whom the towers were meant had no use for them in their planned shape. From that moment they were free to define what kind of tower they wanted to build, however the system of traffic separation remained. The developer proceeded to build an enormous structure (about three stories tall) over the natural ground called, roughly translated, The Slab. The Slab is the main pedestrian space that integrates all the towers into the mass transit network of metropolitan Paris and the commercial activity of the district. The centre of The Slab (seen left) turns out to be the ceiling of the gigantic mass transit station (seen middle) that distributes 150,000 people to and from their offices morning and night. The buildings at La Défense do not have any connection to land or streets, they float upon The Slab.

This project is said to be one of the flagships of the French state, but the interesting thing about this is that the state had to go around its own system of land administration in order to create it. Municipalities in France are organized around 36,600 communes whose statutes regarding urban planning and land use are strictly defined in the legislation of the administration. La Défense does not have an administration in the same sense that communes do. It was created as a national interest operation, meaning that the state, realizing that its own territorial administration system could not deal with a project of such complexity, declared a zone of territorial exception where the legislation was suspended. Instead, the land inside the zone was purchased by a developer, the EPAD, whose statutes are defined by private business law but whose majority shareholder is the state. In other words, the state had to go through the market to avoid flaws in the system of government in order to create a market unlike anything the country had seen before.

The EPAD has since operated profitably by investing in land improvements, most importantly paying to bring regional rail and metro links to the district, and selling development rights for towers that are limited by contract to certain open-ended morphologies. No one owns land there except EPAD, but private companies do own their buildings. Those buildings never could have been built had EPAD not created a market for them through the expansion of the mass transit network it paid for, and of course by building The Slab.

EPAD, an organization who was meant to last at most 20 years, celebrated its 50th anniversary this year while many people struggled with the “outlaw” nature of its existence. Proposals for reform all crash against the challenge of The Slab and how it could continue to function as a form of urbanism within the framework of standard territorial law. This territorial law is itself being questioned and most likely headed for reform, although there is no guarantee that reformed law will be competent to handle a structure of this nature. The way things are going, it’s possible that EPAD could have a longevity comparable to the City of London.

The lesson of La Défense is that for-profit enterprises can create urbanism, markets for land supported by large capital structures, provided that the law allow them to. In other economic sectors this arrangement is nothing unusual. To persuade Republicans and Libertarians of the benefit of urbanism, it suffices to make a comparison with the New York Stock Exchange company, an icon of capitalism. While the service the company provides is a means to trade stocks efficiently, this service does not come free. The NYSE occupies some valuable real estate in downtown Manhattan, and provides sophisticated computer equipment and trading services to participants. You must pay for your right to take part in the NYSE, and then obviously must pay again to buy shares. Your ability to trade shares may not be possible without the supporting capital investments of the NYSE company. The NYSE, although it creates a market, is itself competing in a bigger market, that of stock exchanges. It must be better at enabling stock trading than other stock exchanges in order to attract traders and companies, and it can itself be bought, sold, merged or spun-off as a company. The stock trades are a market that is nested within the market for stock exchanges.

For the liberal-democrat wary of such fine capitalist institutions, the work of market creation can also be done by a non-profit organization. This is what one of my favorite examples, the Wikimedia Foundation, does with its different wikis. Although the trades are free, the foundation does provide the framework for people to rapidly and easily share and structure information. A foundation which owns land could in the same way create a market for buildings by enabling its inhabitants. It is exactly such a process that Christopher Alexander described in The Oregon Experiment. By his proposal, the University of Oregon was required to provide design assistance to faculty and students who wanted to initiate building projects. This form of market would obviously put enormous power in the hands of the users and less so in those of big developers, which is the opposite of what municipal planning systems have done.

Municipal planning systems, as we have known them for the last two centuries in America, have been held up by two pillars. The grid of streets and later on the supergrid of arterials have urbanized land in a manner that favored land speculators and developers, and then the large land speculators and developers. The second pillar has been the zoning ordinance and building code, a system of bureaucratic regulations that has grown in size to the point where consultants must be hired to navigate the process. The non-professional who wants to build something in this market, if he has been lucky enough to benefit from the grid, must first understand a stack of regulations that will take him enormous effort to master. This cost evidently favors developers who have a lot to invest in building and discourages the creation of the small events, quirky house, shops and businesses, that make a city so pleasurable. Bureaucratic regulations also have the nasty side-effect of being unable to translate qualitative standards into rules, the result being a long list of quantitative regulations that produce big subdivisions, big malls and big business. The SmartCode, 60 pages long, does not improve upon this process. It makes the big subdivisions take a different shape.

Paris' 16th borough (front) and La Defense (back)

The 16th borough of Paris (front) and La Défense (back). Two different markets creating two different emergent morphologies, and different environmental qualities as well. Those are choices.

The creation of the municipal system in Europe was an act of land reform, breaking down land estates that had their origins in feudal privilege. The French communes were the product of the revolution, and the municipal corporations acts of Great Britain in the 19th century put an end to quite a few “rotten boroughs.” The end of the feudal tenure system could be justly seen as progress by Europeans, and the new powers wielded by municipalities did not exceed those wielded by the previous landlords. In America the incorporation of land into municipalities, and the transfer of ever greater powers to county governments, took place at the expense of small land owners who considered themselves independent and resisted the limitations imposed upon them by new municipal regulations, while profiting at the same time from the new markets created for their land by investment in structural improvements, most of all roads. Both processes for creating municipalities have since been the monopoly of governments, and the slow action in creating, dissolving, merging and splitting cities has caused crisis in all areas. Alex Marshall points out that state governments have the authority to create and merge municipal corporations, and should make use of this authority more often, but governments only have limited attention to devote to these issues. In the early 19th century it required an act of government to charter any business corporation. The regularization of this system allowed businesses to incorporate without going through the legislative process, and the dynamic market economy we have enjoyed since has this process as one of its foundations. For some reason it was never thought of to extend the same rights to city corporations.

In their pleas to “leave things to the market” Americans severely restricted what kind of operations municipalities could undertake, and limited their authority to take action against public problems. In doing so they did not realize what kind of market was being created, and who would benefit most from it. A municipality that does more is no less of a market than one that does less. A municipality that builds a hierarchical grid of differently-scaled streets and helps non-professionals to create their own buildings would be creating a market, and ultimately an emergent urban morphology, vastly different from what limited municipalities have been allowed to create. More restrictive rules could also create environmental quality that would raise the value of the market as a whole. The municipality could be creating a better market than it currently is if it had more freedom to act.

Inventing and organizing such a municipality will itself require a process that systems of government cannot handle. This is where things truly ought to be left to the market. Independently owned and operated cities could adapt and reorganize themselves to experiment with new forms of markets. They could merge and spin-off to meet the challenges of metropolitan scale. They could buy the land that they intend to urbanize. They could regulate the land to preserve the quality of the environment and create greater neighborhood value. They could make the immense capital investments in roads, mass transit, public squares, parks and utilities that would earn them a profit in increased rents from their markets. Finally, the disintegrated land creation institutions brought about by the modernist program could be reintegrated in cities with enough authority to employ them efficiently and productively.

Sprawl would soon after be a footnote of history, along with many other urban ills.

References

How Cities Work by Alex Marshall

Streets and Patterns by Stephen Marshall

The Oregon Experiment by Christopher Alexander

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.

Reference

Wikipedia and Beyond: Jimmy Wales’ sprawling vision