Tag Archives: Urban Fabric

Decoding paradise – the emergent form of Mediterranean towns

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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.

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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

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Tunisia

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Andalusia

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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

The challenge of dense sprawl

When looking at such a picture we are at first inclined to make a parallel with the landscape of Los Angeles. It is a foggy urban plain with a cluster of towers popping out over the horizon. This is Dubai from a perspective that is rarely shown, that of the city in the foreground, and its suburban expansions in the background. The towers are the Dubai suburbs, lined up on what used to be the main highway out to Abu Dhabi, now the centre of New Dubai and the urban fringe of Dubai. A picture such as this is significant because the central core of Dubai is almost never seen in the pictures of the huge developments going up in its suburbs. That is unfortunate, since the reason that these suburban developments are economically possible at their size is because they are growths of the old Dubai. The parallel with Los Angeles is therefore incorrect. Los Angeles followed the standard American model of urban growth, developing a central business district on a simple grid where the original center of the city was founded, then later adopted suburban sprawl to continue its growth and grew a cluster of skyscrapers adapted to this sprawl where the center once was. The policy of sprawl is blamed for the impossible traffic congestion that cripples Los Angeles, but generally what is meant by sprawl are the low-density housing subdivisions, office zones and other standard typologies of suburbia. The solution that was called for was more density, even though some geographers pointed out that Los Angeles was already one of the densest cities in America. The result of this choice has been dense sprawl: worse traffic, worse crowding and seemingly no improvement in quality of life.

Clearly the challenge of sprawl has been improperly identified. I will show that sprawl is not about density but about distance between complements, and the extremely rapid urban growth of Dubai, from a small fishing town to an urban metropolis in two generations, makes this visibly explicit.

Perhaps the most fascinating fact about Dubai is how natural and complex the old city seems to be despite having an entirely modern building stock. Most cities associated with a natural or organic morphology are usually pre-modernist cities of old classical or vernacular buildings, or at least preserve some of them. There are no such buildings in Dubai, the city having started its growth period in the 1950’s. The only explanation for the natural form of the old Dubai is a natural process of growth.

The urban fabric of a city is a solution set, each building being a solution to a problem of a particular time and place. The city as a whole is a solution set for its population as a whole, and as times and people change new buildings are added to provide new solutions to these new problems. The reason that naturally grown cities have a chaotic morphology is the same reason why stock market movement is fractal; they are both adaptations to fluctuating circumstances, and they are both limited in size by the previous size of the system. That means that you cannot grow a city by a development that is bigger than the city’s current state of maladaptation to circumstances. Attempting to do so will result in economic failure. Many very small development operations done in succession will be much more adaptive than one large development operation planned at one moment, since each operation adapts to the circumstances created by the previous one.

Because cities grow by correcting maladaptations, the new buildings turn out to be complements of the existing buildings. It makes no sense to make a building that is identical to one that already exists, and in natural cities that will never appear. Each building will be fitted to the particular knowledge of time and place, as Hayek would say. This particular knowledge is itself produced by the presence of existing buildings and the way people use them.

This process is not simply an economic abstraction, it also has morphological consequences.

Jumeirah is a beachfront suburb directly to the south of old Dubai that has become the home of the Anglosphere expatriate community as well as synonymous with upper-class lifestyles. Because it is more recent growth of Dubai’s urban centre it has seen growth in operations of much larger sizes. You can tell that there are now “clusters” of identical buildings, nothing of the scale of a metropolitan subdivision yet, but the building individuality of central Dubai is no longer present. (Cluster housing development is also visible in, for example, the older parts of Las Vegas.) This is pre-subdivision scale, in that an operation creates multiple buildings without having a scale large enough to be “planned” and have status as a named development. For the purpose of the adaptation they bring, they are still only one event, only one adaptation subdivided into multiple buildings. And because they are much bigger than the previous development operations, they create more distance between themselves and the urban fabric they are adapting to. The scale of development is not big enough to be called sprawl yet, but the complexity of this neighborhood is not as advanced as that of the older city. While the buildings in Jumeirah are certainly complements of the whole city of Dubai, they are not complements of each other, which is true in the older city.

Left: Skyscrapers on Sheik Zayed Road, Burj Dubai site on lower left

Right: Palm Jumeirah, Dubai Marina megaprojects along with random subdivisions.

Here are Dubai’s world-famous megadevelopments, which have been made possible as adaptations to Dubai’s metropolitan scale. The development operations are enormous complements of the existing urban fabric, but the fact that they are all being built concurrently means that they cannot adapt and become complements to each other. With little surprise the traffic congestion on the Sheik Zayed Road that integrates them together has skyrocketed. The distance between complements has increased to the scale of the projects, and the only way to move from one to another is by driving down Sheik Zayed Road.

The skyscrapers going up are actually making sprawl worse the same way that a development of 100 houses extends sprawl. The idea that a skyscraper is a vertical city is a myth. Skyscrapers are identical floors of open space and rely on very large networks of complementary urban fabric to work properly. Skyscrapers can contribute to the complexity of a place like New York City because the urban fabric of Manhattan is very rich and can digest density and congestion gracefully, but in a city where urban fabric is undeveloped, as modernist plans for a Radiant City were, or has been de-developed, like the CBD of most American cities, skyscrapers throw congestion and traffic out to the whole city as badly as a housing subdivision.

The solution to sprawl is not increasing density, but increasing complementarity. That means breaking up existing housing subdivisions, office parks and shopping centers into smaller autonomous parts that can grow into buildings that are complements to houses, offices and shops as well as complements to the city as a whole. (This obviously implies abolishing zoning.) It means not trying to design everything that goes into one project, to let growth come to you and to accomodate it, to publicize the chaotic symmetry of old Dubai as a model of natural beauty instead of the iconic forms of the skyscraper cluster. The Dubai Palms and the Burj Dubai district may still grow into something natural and complex.

Dying in dignity – Berlin and the American City

The whole class went on a study trip to Berlin last week. The city is mesmerizing in the way it clings to life despite having been the site of tragedy after tragedy in the past century. This made the appearance of renowned American urban history professor Kenneth T. Jackson at the technical university somewhat ridiculous, as he chose to begin his talk by speaking of Detroit.

Jackson, the author of Crabgrass Frontier, is a specialist on the suburbanization of the United States in the post-war era, and he pit the blame for the collapse (there is no other way to describe it) of Detroit on Federal housing policies, racism, and cheap wood-frame home construction. Between pictures of abandoned skyscrapers and mansions, and riot neighborhoods turned to meadows, Jackson built a diagnostic of suburbanization that is entirely political. At no point did he ask himself if Detroit was a good place to live in. From what we know of it, it wasn’t that great of a city. In comparison to the glory that was Berlin, it was a horror. If politics was the explanation for suburbanization, then the suburbs would not be so qualitatively different from the cities. But Jackson never mentioned that. Of everything I’ve read from Americans complaining about suburban sprawl, not once does anyone ask if American cities were good places to live. They weren’t. A few days in Berlin was all it took to understand that.

Unlike Paris, which was a medieval city that was intensively renovated in the 19th century, Berlin was a small burg of 150,000 at the beginning of it, about one seventh the size of London. Berlin’s growth took off in the mid-19th century at a pace and a time similar to New York City, both cities hitting about 2 million in time for the fin de siècle. Berlin is therefore a modern, industrial city of the same class as all the Great American Cities praised by Jane Jacobs. That is why, every time I turned a corner in one of its broad streets and avenues, I couldn’t help but feel “this is what an American city would have been if Americans had known how to make cities.”

American cities have been a mess for so long that American urbanists have been fighting what is essentially a hopeless struggle to save what has never been worth saving. New York City, with its grid plan repeated endlessly, somewhat accidentally became a great city and was retroactively manifestoed by Rem Koolhaas in Delirious New York. The rest of the country was not so lucky. Of the Great American Cities, only three more survived: Boston, Chicago, San Francisco. It wasn’t just de-industrialization and racism that did it. Chaos is synonymous with urbanity in America. The New Urbanists, who promote a more refined form of urbanism, have been labeled as “too suburban” by some of their critics. What they propose is functionally identical to Berlin.

What really happened to the Great American Cities? They annoyed their citizens to such an extent with awful living conditions, high costs and endless political conflicts that the suburbs, with a promise of peace and quiet, easily outcompeted them. The exodus of the middle class then fed the chaos even more. What if Detroit collapsed because the people who ran Detroit were objectively corrupt and incompetent at producing cities?

In Berlin we have a modern city that has faced a hundred years of chaos, and a hundred years of industrial growth beforehand, and come out of it gracefully. The city is economically in no better shape than Detroit. It lived for almost 50 years in a completely artificial state, serving as a demonstration of wealth for both the East and the West. With the wall down, the subsidies were taken away. The population fell lightly over the next decade, and the economic promise didn’t materialize. Today unemployment is around 14% and kids are migrating south where there is better hope for work. There are empty office buildings all over. The city government is broke. Suburban sprawl is expanding. Despite that, Berlin is full of construction cranes. Walking around the lovely Prenzlauer Berg, its buildings restored fresh after years of neglect under the Socialist Republic and now invaded by young families, Berlin does not give the impression of a city struggling. It is what Detroit never was and certainly isn’t today: a place that feels good. This is why people are willing to stay here. This is why private money is funding the reconstruction of the Hohenzollern palace on the wreckage of Palast der Republik, just behind the bigger than life statue of Marx and Engels. There are enough people out there who love Berlin and will sacrifice for it. Berlin will remain a relevant city even as it stagnates or shrinks. It will have everything a state-of-the-art city is expected to have. Whatever needs to be invested will be invested. New train stations will be built and they will work better than any train station you’ve ever seen. (The new Hauptbahnof is a sight for sore eyes.) Some derelict neighborhoods will have to be abandoned, much like some Detroit neighborhoods have turned into meadows. I’m sure the Berliners will find something useful to do with them, perhaps barbecues with curried sausage and sauerkraut. Complexity science tells us you can never stop growing a city, even if it is shrinking in size. The urban fabric has to be recycled. When it stops, as is the case with Detroit, the city is dead.

One thing that is scarcely mentioned about Berlin urbanism today is politics. Berlin is tired of politics. “No more experiments!” was the proclamation of city planners when postmodern architects came swarming in favor of new plans after the reunification. However boring the vision for Berlin may be, it is graceful, dignified, and has gathered popular support. Americans, I’m afraid, are unable to conceive of cities as anything other than political objects to fight over. Everything must be fought over, even the most redundant parking space in Brooklyn. That is why I don’t expect anything other than more chaos to come out of America in the short-term.

Prenzlauer Berg Prenzlauer Berg