Tag Archives: New York

The patterns of place

(This article originally appeared in Get Ahead Magazine, for the Get Ahead Festival of independent short films in Brooklyn.)

When we speak of the identity of a place, we express a recognition of the patterns formed around us. We may not be conscious of them to the point of being able to draw them back with precision like Stephen Wiltshire, but we can remember them in the abstract, and in this way, identify different places from the abstractions we recall of their patterns. This is how one street can look sufficiently alike another that we can identify a neighborhood, and it is also why a landscape like Liberty City in Grand Theft Auto can feel like New York City, despite the fact that every object has been reconfigured to create a parody environment.

A city’s identity is made by the patterns selected by the people who built them. We can also say that these patterns are the fossil record of the people who inhabited a place. We can read the history, the culture and the sustainability of a place by the combination of its patterns. A building is a hierarchical computation of different processes nested within each other, and these processes can be substituted for others depending on what conditions are encountered.

Echoes of Holland

At the largest scale of patterns there is the building program, whether a house, a church, an office, easily recognizable in any cultural setting. These programs are realized using construction techniques that are conditioned on economic constraints. The Dutch who settled New York City brought with them their basic house program, but these had to adapt to the resources available by, for example, building in brownstone, an economic pattern. Despite this difference they kept features of their homes like stoops, patterns that were at first environmental but then became cultural.

As each successive culture either migrates to or emerges in the city, it needs to adapt the patterns of its buildings to fit its own practices. Fractals like these become habitual:

This is Chinatown in Brooklyn. We can tell it is Brooklyn because the basic patterns, program and materials, are Americanized Dutch. We can tell it is Chinatown because of the use of vertical commercial signs which are characteristic of oriental cultures (their writing being read top-to-bottom instead of left-to-right). The large-scale patterns are extended by smaller-scale patterns to form a full building fractal that is Dutch, American, New York and Chinese. This combination of pattern is the identity of Brooklyn, the people who have lived there and continue to live there.

One particular culture that has often been denounced as an anti-culture is the global corporation. Their aesthetic program has been to impose their corporate identity uniformly on communities, regardless of any consideration for local economic, environmental, or cultural factors. But there have been exceptions, such as the following case, where the corporation decided to extend the patterns of the neighborhood instead of imposing its own.

This Dunkin’ Donuts nested itself seamlessly in an old Dutch building next to a Chinese restaurant, and even improved upon it a bit with orange awnings that preserve the structure of the windows while announcing the presence of this corporate neighbor to everyone on the street. As well as being a demonstration of Dunkin’s neighborliness, it is also a demonstration of the sustainability of the neighborhood. The buildings are resilient, and despite the Dutch builders never anticipating that there could ever exist such a thing as a Dunkin’ Donuts, their patterns have been slightly adapted to fit today’s needs. Some day Dunkin’ Donuts will also be history. In its place will be some other culture which may or may not preserve traces of Dunkin’s presence, but the building itself will remain and serve a new purpose.

So far I haven’t said a word about architecture, which is simply because architecture does not enter the picture unless one has a lot of money for sculptural elements. It is possible to build a good neighborhood without architects, but a great one needs art, and that means getting some architects involved. The best architecture starts with utilitarian patterns, the same functional, economic and cultural patterns we see above, and then expands it by nesting sculptural elements, thus it is still possible to recognize identity of place behind the architecture. This architecture, sculpting the utilitarian shape of the building, becomes the final expression of identity, the artistic currents and fashions that propagate across cultures and then vanish, only to make periodic comebacks.

This is what Brooklyn architects did with these residential towers overlooking prospect park. What is in essence a stack of identical apartments made with the usual economic patterns was extended with sculptural ornament, most impressively around the otherwise obnoxious elevator shafts.

Looking at Brooklyn’s tallest landmark, the Williamsburg Savings Bank Tower, we see patterns that are Gothic, Romanesque, Italian renaissance, Art Deco, all nested within each other and wrapped around a stack of floors that can fulfill any purpose whatsoever. The final product is a building that is worth preserving from a bank, to dentist’s offices, to residences, because the patterns cooperate with each other instead of clashing, and answer our need to feel connected to any of these identities. This is another form of sustainability.

The tragedy of architecture in the 20th century, and the great confusion that came from it, is that modernist architects first banned sculptural elements in favor of purely standardized, globally uniform, utilitarian industrial patterns, then post-modernist architects declared that a building was only a sculpture for living, that the utilitarian should be subordinated to the architect’s artistic expression. The outcome has been a building culture that has no identity when it is not completely incomprehensible, and more than likely has no resilience and no future.

This “Dance Center” is a sad example of this confusion. Were it not spelled out in letters, would we be able to understand anything about this building’s identity? The people who occupy it? What any of its parts do, or if they do nothing at all and are simply there for visual effect? I can’t imagine a future for it. But there is worse.

This building makes no attempt at being anything other than mass human storage, the modernist tower block revived for the bubble epoch. It will likely be a financial failure for being too ambitious while being too redundant. If I were to take an apartment there, it would be impossible for me to tell which window is mine from the outside. What does this say about the people who built it? That they took the easiest path to financial income. What does this say about the people who will live there? That they have nowhere else to go. It is and will remain an alien in the neighborhood, a product that removes identity instead of contributing to it.

Today’s planning establishment attempts to reform the shape of our cities with “form-based codes” that dictate with precision the shape of every pattern. This comes at the cost of outlawing certain unforeseeable patterns that may make a net contribution to the identity of place. It also drives away people that need these patterns, and drains life that is needed to renew the neighborhoods. Last of all, it will not stop a monster like the example above. If instead of dictating shapes, we made it clear how to expand and preserve the neighborhood’s identity, we would all be much freer to live and express ourselves, adding to the history of our environment.

Defining a new traditional urbanism

Sometime last year this website attracted the attention of several members of the International Network for Traditional Building, Architecture and Urbanism, an organization sponsored by the Prince of Wales Foundation in order to support and renew traditions of construction. While this organization does great work to preserve the techniques of traditional building cultures, they have yet to define what the traditional urbanism of their name really implies. The importance of such a definition I believe to be primordial. If modern planning measures continue to be adopted from one country to the next, any traditional technique of construction will become irrelevant, as they have in western industrialized (and post-industrialized) countries.

This all became obvious when a miniature controversy erupted and swept through the various internet discussion groups and blogs of the community over a proposed redevelopment of the Chelsea Barracks in London’s Chelsea borough. An old modernist military installation was to be torn down and replaced by its new owner, the Emir of Qatar, with a new modernist megahousing development designed by Lord Rogers. There was nothing particularly interesting about this Rogers design, but Lord Rogers having written the plan of London, a plan that specifically calls for better design, it made sense that a Rogers design would be swiftly approved by the planning authorities. Hiring Rogers was the most risk-free option available for a multi-million pound development project.

Getting wind of this, and noticing that the Rogers design was an unremarkable piece of rehashed modern housing, the Prince of Wales hired his preferred architect Quinlan Terry to sketch up a counter-proposal that was more in harmony with the architecture of the landmark Royal Chelsea Hospital across the street from the barracks, which he then proposed to the Emir of Qatar through his personal relationship with him. The Emir, alien to the local culture and uncertain of what London considers to be “good design”, then decided to dump Rogers and re-think the development.

The Prince Charles and Quinlan Terry counter-proposal

The Prince of Wales and Quinlan Terry counter-proposal

Lord Rogers' Chelsea Barracks redevelopment proposal

Lord Rogers' Chelsea Barracks redevelopment proposal

I am not going to analyze the controversy from all of its fascinating angles, such as the design quality of the architecture, Lord Rogers (of the House of Lords) teaming up with British Republicans to denounce the monarchy’s interference with civilian life, or the absence of affordable housing in Chelsea. I am interested in only one question: is this traditional urbanism?

At first sight, the Terry design is reminiscent of the 18th/19th century style of palatial construction in Europe. (In fact one of the “blocks” features echoes of Buckingham Palace.) In terms of authenticity, the proposal is flawless. The Rogers proposal is also a palace, although one with much fewer attractive qualities. But does Chelsea really need a palace?

Providing a response to that inquiry is precisely what a system of urbanism is supposed to achieve. The system in place for London unfortunately requires that one have enormous financial means in order to participate in any kind of development, and inevitably that implies that only large speculative development will be so much as imaginable. The Chelsea Barracks proposal is entirely a product of modern urbanism, and by intervening into that system, the Prince of Wales and other traditionalists are sanctioning the very thing they claim to be opposed to.

As luck would have it, I wrote about the different processes of urban development using London neighborhoods such as Chelsea last year. Combining this with our models of the processes of urban emergence, we can develop the idea even further and try to conceive of a proposal for a traditional urbanism that develops the Chelsea Barracks site.

When I last covered Chelsea, I used its housing typology as an example of a linear, non-complex model of housing development. While linear housing is characteristic of the neighborhood, it is not the entire tissue of it. If we analyze the morphology of the neighborhood we find many clusters of housing rows, but these clusters do not necessarily repeat from one block to the next, and they are intermingled with other, uniquely programmed buildings of varying scale, the most prominent of which being the Royal Hospital. This means that, despite the neighborhood’s texture being only semi-random and not completely emergent, it performs at a remarkable level of complexity.

Chelsea

This kind of fabric is very common of British-American subdivision development during the 19th century. Here it is in a pure grid form in one of Montreal’s inner core “Plateau” neighborhoods.

Montreal

We can observe that the middle of blocks is populated very differently from the major streets, despite the fact that they are not very different from a design standpoint. We don’t need to propose anything more complicated than self-optimization to explain this pattern. During development, housing builders would work from the center of blocks outwards, where there was the least perceptible traffic, and shops, churches and other activities located where there was the most traffic. The outcome is a complex tissue with perceptible characteristics, not only random noise.

In comparison, here is the texture of a new neighborhood in Las Vegas (Henderson), Nevada.

henderson

It is the same housing model repeated a thousand times, some lots facing backwards from the main roads. This new neighborhood might as well define linear development processes. The only feature of this neighborhood is the house, and so it can only function at any level of complexity by ejecting its residents out into town for any activity.

Of course some might say this is not a fair comparison. Those old neighborhoods are old, and therefore have had a long time to achieve maturity. But a neighborhood maturing implies that the neighborhood is planned to have a life cycle taking place in time, of which the early stage of growth is critical to its final morphology. What did a young, new neighborhood look like in 19th century British-American urbanism? It consisted mostly of very large lots of gardens and other large events (such as, for example, a Royal Hospital). These new neighborhoods were advertised as a pastoral refuge from the city. Look at this engraving of Milwaukee’s outskirts in 1858.

Milwaukee_1858

Its overall density is much lesser than that of Las Vegas new neighborhoods, and it has a distinctively pastoral quality. Yet what happened to those traditional neighborhoods was often that, very rapidly (the span of 2-3 decades) they became very dense urban neighborhoods, at which point the rate of new growth plunged and the fabric remained stable.

See for example this comparison of the urban fabric (1897-1915) of the Morningside Heights neighborhood of Manhattan, from the book Retrofitting Suburbia: Urban Design Solutions for Redesigning Suburbs.

MorningsideHeights18971915

In less than two decades the neighborhood was populated from a pastoral grid dominated by the campus of Columbia University to the dense, New York-style neighborhood it remains today. In these examples, growing a mature neighborhood was intrinsic to the development process adopted, and once this process wound down there was very little left to change to it. The neighborhood was mature because it had reached its equilibrium with the socio-economic context. Correcting deficiencies is what is meant by a neighborhood maturing, and developing a mature city implies that one is avoiding mistakes during its development. If we are employing a development model that is set in advance, no mistake can be either corrected or avoided during production.

Notice then that in traditional neighborhoods, the construction of mass-produced housing came last, after the neighborhood had established itself as a socio-economic system at the fringe of an existing city. Because of this, the mass-produced housing is a complement to that tissue, and contributes to the established complexity of the neighborhood, even super-charging it with population density. This not only ensured that there was no environmental alienation for the new residents, but also that there was a limit to how much repetition there could be from housing builders.

In modern urbanism we require all new developments to be programmed for a certain type of use, whether we are building a housing subdivision, an office or industrial zone, or a “mixed-used” development. If this is not know and debated in public, no development project can be approved. Only when a proposal has gone through this ordeal can anything be built, and making changes involves going through the process again, so the developers just subsidize the mistakes, or leave certain parts of the plan unrealized and a gaping hole.

In traditional urbanism this is never necessary. In fact it is possible for entire blocks to be left as pasture or gardens, creating an ultra-low density urban tissue. Only as further development becomes truly needed are these blocks transformed into housing and other programs. A critical difference is that no planning permit or approval is necessary to further develop a neighborhood. Instead the residents have an envelope of building rights set in building codes, and everything within that space is considered to be automatically approved. Because of this the development of a neighborhood can be undertaken in a large number of successive decisions, where the next building to be added is not only determined by the citywide market but also by the current state of the neighborhood. This in turn allows a local community and economy to grow, which is absent from modern developments.

This is all very interesting for new neighborhoods, but how would that apply to a small urban redevelopment site in the middle of a centuries-old neighborhood? Clearly we aren’t going to be building up from pastures. This is where a “new” traditional urbanism becomes relevant, as we need to invent a new process that restores the features of traditional urbanism, but can also function in the context of mature cities and modern structural requirements.

Although the redevelopment of a large urban block is usually undertaken as a large real-estate project, it can also be considered as a nested process of urbanism (urbanism within urbanism). Much like the city-wide process of urbanism is characterized by regulations intended to achieve equilibrium, the redevelopment of a block of the city should also be designed as to achieve its equilibrium with the city as a whole but (and here is the defining characteristic of a traditional urbanism) also within itself. This is what does not happen in linear development processes such as housing subdivisions, or 19th century housing terraces. They provide equilibrium with the larger scale, but amongst themselves they provide no complement. For this reason, although you’re likely to see a lot of some housing model repeated in one place, you’ll rarely ever see it used again elsewhere. Mass-production does not work for buildings the way it does in automobiles.

Time and interaction are the critical factors. The reason large-scale development like the Rogers and Terry proposals get approved and built is that everything must be conceived and approved in one step. The architectural design is rushed in order to make proposals as soon as possible. The form can’t evolve over the course of development. This process is justified by the need to control the architectural character of the city, but it is not necessarily so. It only follows from controlling architectural character because we rely on static information systems and processes to conduct building. In fact, many of the traditional building techniques that preservationists are attempting to preserve do not translate into modern information systems (building plans). If instead of drawing the full plans, the proposals simply supplied the component patterns and a parameter space for them, then there could be an infinite variety of different instances of these patterns populating the new space, all fitting a particular need and applying a specific method of returning to equilibrium. If we wanted to release control even more, we could define some buildings from the neighborhood as models and whatever patterns they featured as automatically approved. And seeing as this is the 21st century, we could define these patterns inside software that could randomly generate any possible permutation, such as the City Engine.

With the architecture out of the way, there would only need to be a fixed design for the frame of spaces around which the urbanization will take place. Grids are flat and unspecific, and so a good project will have a place structure that creates inequalities of movement. (Even New York’s grid has subtle inequalities in the short-blocked avenues and long-blocked streets, creating vastly different spaces in character.) Crescents, squares and alleys on a completely open surface should be the extent of planning a new neighborhood, and it will be important that this design have value all of its own. It is quite possible, for whatever economic reasons, that only part of the surface will be built, or even that nothing will be built. A good urban design must work in all states, including with nothing on it. Remove the buildings from the Terry proposal and there is still a rather interesting landscape. The Rogers proposal, without its buildings, has nothing. Terry is therefore much closer to the goal.

Negative space in modern plots

Negative space in modern plots

In the final step, how does the developer make money? Sustainable development, after all, has to be profitable in order to be sustainable. In a traditional city, plots were subdivided over time as the need arose. In a modern city lots are defined as a standard shape, and then later sold off for some standard price. This approach has the unfortunate side effect of creating a lot of negative space. The developer of the Chelsea Barracks could instead sell or auction off space as an elastic product. The first buyer would choose the first spot on the open surface, in relation to the hierarchy of the urban grid. The second buyer would place himself in relation to the urban grid and the first buyer. These buyers at first would come from long-time residents of the neigborhood aware of some particular way of extending the neighborhood, but unable to find a lot a space at the right size before this project became open to the public. This process would continue until all the space had been consumed, and the end result would be that all buildings would be related to one another through the sales process. If the space was priced high enough, the later projects would only be initiated after the initial ones had been completed, and the impact of time would generate the demand for building programs complementing the initial projects.

In such a way the urbanism within urbanism would create its own socio-economic subsystem, would feature a randomly adapted but uniform architectural signature, and would complement and extend the external urban tissue.

While I’ve detailed a process for developing a small block within a city, this process is just as applicable for doing development of new cities, or new suburbs of cities. There are fewer constraints and difficulties involved in these other cases, which is why I wanted to use the example of the Chelsea Barracks site. Urbanisation is a universal phenomenon, and although the patterns change, the underlying principles are everywhere the same.

A pattern language for New York streets

The New York City Department of Transportation has published its street design manual, a collection of patterns that make absolutely no references to any traffic control devices of any kind. This is the result of the revolutionary transportation commissioner and, let’s admit it, traffic anti-planner Janette Sadik-Khan (NYMagazine article on her rise) who has launched a mini-revolution since being appointed to run the street bureaucracy of New York City two years ago. Traveling around the world to learn what was being done the best, and falling under the influence of Jan Gehl along the way, she is the living proof that visionary leadership can turn even the most entrenched bureaucracy around.

You will notice that the manual distinguishes between ribbon sidewalks (totally useless) and full sidewalks (the bare minimum). In fact they couldn’t even find a picture of a ribbon sidewalk with people walking on it.

What this mini-revolution has meant is that the Department of Transportation has been abolished in all but name, admitting the reality that cities do not have transportation, they have spaces. It has also meant that the autocratic, yet highly productive, legacy of Robert Moses has made a comeback. Moses set out to transform New York into a city of the 20th century. Sadik-Khan is transforming his legacy into America’s first city of the 21st century, with the same initiative, inspiration and leadership, but with more human and sustainable ends to realize.

Thanks to the pro-urb list for the scoop. You can monitor New York’s street revolution in real-time on Streetsblog.

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

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.

A demonstration of complexity in New York City

This discussion originally appeared on the Wired New York forums.

Allow me to point to a great example of contemporary emergence in New York City, and perhaps clarify the principles involved.

This, as most of you probably know, is Times Square.

There is a geometry to Times Square that makes it different from the rest of the city, that is to say there is some pattern in Times Square that is shared by every single building and not shared by buildings in the rest of the city. This pattern is the shape of the advertisements.

Those advertisements are not random. There is a complex order to them. The Times Square zoning regulations require that advertisements be placed, in relative (to building floors) proportions, on each facade. This was the result of an intervention by Robert A. M. Stern in the early 90’s. This building code is a localized instruction given to each individual building, that constrains what the owners can do at one scale but gives them total freedom to personalize within that scale and beyond that scale.

The resulting pattern, no matter what advertisements are swapped in for other advertisements, is a place that is immediately recognizable. The code has created an organic symmetry. Should the same code be applied somewhere else in the world, it might be mistaken for Times Square.

Times Square is a system where different individuals, applying the same rule to their own individualized problems, work together without consciously being aware of it to create a large-scale geometric order.

Didn’t Times Square have advertisements beforehand? From the point of view of complexity science, it is irrelevant where the rules that generate complexity came from. It can be from culture. It can be tradition. It can be imposed by government. It can be a multilateral protocol like the Internet. It can be just the physical nature of the thing, like cells that follow their DNA to generate organisms, or it can asserted as abstract logical constructs, like the Wolfram elementary cellular automatons, in which cases there is no will involved in following the rules.

What makes something emergent is this feature: localized decisions unconsciously create large-scale form by following a set of rules shared by other local decisions while solving local problems.

All cities, without exception, are emergent. Even Brasilia has favelas. There is just no way for one single human mind to design at that scale. Even if you were to build a plan for millions of apartments in neat rows of housing complexes, if someone so much as built a shack outside of your sphere of control, the experience of moving from that shack to the housing estate would be emergent. There was never a mortal power, from master builder to god-emperor, capable of avoiding that.

However not all cities are complex, and this is what we generally term an organic city. Complexity means that the city is solving multiple problems at multiple scales concurrently (it is fractal), which means that not only my house and my neighbor’s office are fitted to their task, they are also fitted to their street, their neighborhood, their borough, and the metropolis as a whole. And the street is fitted to its space and the neighborhood, and the neighborhood is fitted to borough, and so on.

As we’ve seen in the past century, a lot of emergent processes are first of all completely accidental, and second complexity-destroying. But even the most boring of suburbia looks “organic” when you zoom out the scale far enough, because at that point it escaped the control of any single individual.