Is it time to revive the pattern language?

Software and other fields have made brilliant progress with the methodology, while built environment fields lag badly – mired in parochial debates over a 1977 bible-like volume

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Launch of A New Pattern Language for Growing Regions: Places, Networks, Processes book and wiki at the 2020 World Urban Forum in February. Wiki inventor Ward Cunningham was interviewed by collaborator Michael Mehaffy.

Although virtually everyone uses Wikipedia routinely today, what is remarkable is how few know its surprising provenance in the world of planning and architecture.

Wiki, the methodology that powers Wikipedia, was invented by a computer scientist seeking to create a web-based system to share “pattern languages of programming” – an idea he and his colleagues had exported from architect Christopher Alexander’s 1977 classic A Pattern Language: Towns, Buildings, Construction.

Pattern languages are, at heart, nothing more than “a method of describing good design practices or patterns of useful organization within a field of expertise,” as Wikipedia describes them. The “pattern” encapsulates some key relationship within the set of design elements, which, if configured in the “right” way, will produce the desired outcome. Each pattern typically includes a name, problem-statement, discussion conclusion, and hyperlinks.

The genius of the method is that each pattern is nested within many other patterns, connected by hyperlinks, and forming a relational web-network. The patterns can then be applied in a contextual, language-like way. Software designers clearly found the method enormously productive: pattern languages of programming (or “design patterns”) have been put to use in most game software, many other programs, and many operating systems.

Ward Cunningham, the wiki inventor, actually envisioned each wiki page as a kind of pattern in its own right, with title, photo, summary, discussion, and hyperlinks.  A few years after his 1990s invention, the developers of an early online encyclopedia enthusiastically applied the new system (and its name) to their embryonic creation, with now-familiar results.  Nor is wiki limited to Wikipedia, of course, but it permeates the web (Google Sites, Wikihow, Mediawiki, etc).

Pattern languages have had other phenomenal applications too, growing out of software (leading directly to Agile, Extreme Programming and Scrum) and also an astonishing range of other fields, from molecular biology to sociology to engineering to manufacturing, to seemingly countless others. One can find online citations to papers on pattern languages for music composition, pattern languages for weddings, even pattern languages for writing patterns. (!)

The one field that has lagged most conspicuously is, curiously, the very one for which pattern languages were invented, the built environment. What can explain this anomaly? It seems there are a number of likely factors – the bias of architects against anything that they imagine might limit their “creative freedom” (a debatable idea at best), the greater willingness of other fields, especially technology,  to embrace functional innovation (not just novelty for its own sake), and the more pragmatic, less ideologically constrained nature of other disciplines in relation to architecture.

But perhaps the most powerful explanation is the very success of the 1977 book. Resembling a nothing so much as bible, it is full of pronouncements that were forever locked in print, and never allowed to be tested and refined.  The cult-like veneration shown by some was matched only by the contempt held by others.

Yet this outcome was contrary to the explicit aims of the authors, as they made clear in the introduction:

You see then that the patterns are very much alive and evolving. In fact, if you like, each pattern may be looked upon as a hypothesis like one of the hypotheses of science. In this sense, each pattern represents our current best guess as to what arrangement of the physical environment will work… But of course, no matter what the asterisks say, the patterns are still hypotheses, all 253 of them — and are therefore all tentative, all free to evolve under the impact of new experience and observation. (Alexander et al., 1977, pages xv-xvii)

But that evolution never happened, of course.  Instead, the 253 patterns became trapped in their original bible-like volume, protected even by copyright, and never to be altered, added to or differentiated. Other fields, unencumbered by such a dominant first corpus, made brilliant progress, while work in the built environment stagnated.

So what can be done now to push forward more productive work in the built environment?  Two developments offer an opportunity for a fresh start.  One of them is the development of a new framework agreement on urbanization, adopted by acclamation by all 193 countries of the United Nations, and known as the New Urban Agenda. Many of the elements of the New Urban Agenda can be expressed in pattern-like forms, offering the potential for a new collection of patterns based on this document.

The other development is a new generation of wiki, authored by the original inventor, Ward Cunningham. This “federated” wiki allows copies to be made, shared and altered more easily, using handheld or desktop devices. Its limitations are as broad as the limitations of new app capabilities – data calculations and modeling, field measurements, augmented reality visualization, and a host of other new capabilities undreamt of by the original pattern language authors.

Accordingly, our team, based at the Centre for the Future of Places at KTH University in Stockholm and at Sustasis Foundation in Portland, Oregon, have partnered with Ward Cunningham and other collaborators to develop a new pattern language collection, together with a companion wiki. A New Pattern Language for Growing Regions contains 80 new patterns, many encapsulating elements of the New Urban Agenda.  The companion wiki, at, contains the same patterns in wiki form. The wiki is currently read-only, but will become editable and shareable in the near future.

The companion wiki (available online at can be used on a smartphone or desktop. Each pane is a pattern, linked to other patterns through networked hyperlinks, and able to be navigated and assembled for application in specific projects. The wiki will soon be editable, allowing the revision and addition of patterns for a wide range of potential project applications.

The new patterns reflect not only the New Urban Agenda, but the new thinking about urbanization and its requirements for a more sustainable age – reformist ideas going back to the work of Jane Jacobs and others. They include patterns on mixed use, walkability, public space, multimodal transportation, interconnected street grids, and other characteristics of diverse, well-connected urbanism.  There are also patterns covering historic regeneration, slum upgrading, suburban retrofit, and other timely issues.  Other patterns cover new technologies, like citizen data and autonomous vehicles.  Another category covers implementation tools, including financial mechanisms, governance structures and the like.  A more experimental category covers geometric characteristics – similar to those later explored by Alexander – including local symmetries, fractal patterns, grouping and framing.

As with the first generation of patterns, the aim is to set out normative propositions supported by evidence, and accordingly, each pattern has one or more research citations justifying its claims.  Of course these can all be debated, and the aim is not to end discussion, but to begin it.  If another party has an alternative pattern, justified by alternative evidence, let them present it, and let us have a proper debate on the evidence.  Let us not continue to argue ex cathedra for sectarian dogma. That is not how the other fields have made such progress in meeting their challenges.

Another point is the normative nature of the patterns. These are unabashedly so, in the belief that all work in the built environment is shaped by normative judgments, and the only question is whether these values are on the table for examination and challenge. As Kevin Lynch pointed out in Good City Form, the danger is not having values, but failing to make them transparent. Too often these values are cloaked behind claims of expertise or artistic privilege, rather than sound examination and collective evaluation.

Some will note that we adhered closely to the original design of the patterns as printed in the book.  This is because the original patterns have been proven user-friendly and successful, and attempts at altered versions in the built environment have proven less so. Furthermore, a similar format also helps to make the original patterns more useful as part of larger project-based collections.  Alexander and his colleagues also described “the essential purposes behind this format,” which suggest that alterations without cause are unwise. This project is intended to be rooted in evidence of what works, and the evidence that the original pattern structure has worked is undeniable.

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Copes of the new pattern language book on display at the World Urban Forum.

Finally, this project is meant not as an end but a beginning.  The first collection of 80 patterns is only a small and partially representative sampling of what is possible, and surely necessary, as we confront a new generation of challenges.  The wiki should make it possible to produce many hundreds or thousands more, just as Wikipedia grew from a few hundred entries to today’s vast collection. The patterns can be collected periodically into print editions, or continue in online form, or both. More importantly, they can be applied to specific projects and specific contexts in different parts of the world, adapted, refined and added to, so that the most universal patterns can be widely shared, and the entire collection can grow and diversify.

Whether or not this particular project is the spark of a revival of pattern languages in the built environment, we are convinced that such a revival is long overdue.  A profound transformation is under way in our technological systems, reflected by Agile Methodology, Scrum, wiki, and yes, patterns. The transformation is driven by a recognition that the old linear methods have failed us, and we need better web-networked ways of working. In the built environment especially, the need for ways to document and share successful evidence-based design methodologies, capable of achieving desired goals, is matched only by the current gap in achieving them.

Michael Mehaffy is Senior Researcher at the Centre for the Future of Places, and Executive Director of Sustasis Foundation and International Making Cities Livable ( He was a student and long-time collaborator of Christopher Alexander, and he has been a collaborator of Ward Cunningham for over a decade. More information is available about the wiki and book at


Reactionary modernism strikes again

EU urban development policy is taking a big step backward by embracing an outmoded ideology governing new construction in historic contexts

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Under the new Article 16, the faithful reconstruction of, say, the campanile in Venice after a collapse (as happened in 1902) would be forbidden as an “extension” of the “monument” of Piazza San Marco. Instead, a “contemporary” insertion would be required – perhaps like this Madrid building?

Michael W. Mehaffy and Nikos A. Salingaros

Imagine the following scenario. It is 1902, and to the great shock and distress of the citizens of Venice, the beautiful campanile tower in its Piazza San Marco has just collapsed. That very evening, the city’s communal council votes to approve 500,000 Lire for the prompt rebuilding, “com’era, dov’era” — “as it was, where it was.” Future residents and visitors alike may now continue to enjoy this beautiful structure, which had also been restored and added to many times previously.

But then a bureaucrat from far away steps up to speak. “Our standards do not allow this! Our funding policies require that ‘a project shall use contemporary design’ — which means that you may use only current styles of which we approve, and you may not use the traditional styles of Venice. That would be a ‘falsification of history’, a ‘mingling of the false with the genuine’, and we decree that this would have harmful consequences!” The project does not go forward, and something entirely “contemporary” is built instead.

The first part of this scenario did in fact occur — the campanile was rebuilt, to the delight of citizens and visitors for over a century since. The second part of the scenario is in fact what would occur under a current EU proposal governing new construction in historic contexts that would restrict funding for such projects unless they are “stylistically correct” — that is, unless the authorities deem them to be suitably “contemporary” in design.

The last few phrases of the scenario come verbatim from a document written by a group of modernist architects in 1933, one that was deeply influential upon architectural theory — to the great detriment of cities and their inhabitants (and their broader heritage) ever since. Their ideology still haunts current policy, and drives the current proposal. We will come back to examine this point in more detail later.

Meanwhile, the current provision at the EU is “Quality principle/recommendation number 16” of the “European quality principles for EU-funded interventions with potential impact upon cultural heritage.” It states:

“When new parts/elements are necessary, a project shall use contemporary design adding new value and/or use while respecting the existing ones.” (Emphasis added)

This is a subtle but radical provision. In addition to prohibiting the reconstruction of the Venice campanile, it would decree, for example, that the reconstructions of historic Warsaw, Dresden, Potsdam, and many other cities obliterated during World War II, would not be permitted. Individual buildings, too, could not be reconstructed, except as “contemporary designs” — which is to say, again, only those particular styles that the authorities deem to be “contemporary”. To make this determination, civic and political authorities of course defer to architects with a “contemporary” stylistic agenda. That might mean, for example, something like a swoopy new spire would be mandated for the reconstruction of Paris’ Notre Dame Cathedral. The reconstruction of the beautiful spire destroyed by the 2019 fire, or any other traditional design for that matter, would be forbidden.

This provision surely warms the hearts of those architects who would prefer to build their own contemporary novelties, without competition from other architects who may be more skilled in traditional design. However, for the citizenry at large, for city leaders, and for those in other disciplines, Quality Principle Number 16 ought to be deeply troubling, for several reasons.

First, there is the sheer value of economic development in places like, for example, the rebuilt historic center of Warsaw. Tourists come to such a place to revel in its atmosphere and its beauty, and to dig into its history — whereupon they may learn, through appropriate interpretive materials, all about the postwar reconstruction (a historic event in its own right). A prohibition against creating such an economic as well as cultural treasure — forbidden purely on stylistic grounds — would carry potentially enormous negative economic impacts. In some cases, these impacts would be felt most by remote communities that can ill afford to do without the appeal of reconstructed heritage (suitably identified as such).

Warsaw’s beautiful and popular Old Town, a major economic engine of the city. The district was entirely rebuilt after the German army leveled it in World War II.  Such a reconstruction (an “extension” of a “monument”) would be forbidden under the new EU standard. (Image courtesy

Second, there is the troubling spectacle of experts arrogating to themselves the exclusive right to dictate what kinds of environments regular citizens may occupy and enjoy. Human environments must accomplish many goals, only one of which is to tick professional boxes of what some group considers as historic “authenticity”. They must also delight, comfort, support, and adapt to human need. One of the ways we ensure they do so, particularly in a democracy, is to involve the citizens in the shaping of their own environments. By contrast, there is something fundamentally undemocratic about experts dictating “a project SHALL use contemporary design”. Of course, it is those same experts who then deem what constitutes “contemporary” design.

Third, this proposal betrays an appalling fallacy in thinking — namely, that every period of history is “authentically” represented by one and only one style, which is “contemporary” to that period. Therefore, under this logic, every new act of building must be fully legible as to its period of creation, offering up the one and only correct semiotic expression of its historic identity.

This is complete nonsense. History is not a line but a fugue, with revivals and recreations and novelties all mixed up together. Nor is there one authoritative source of the “correct” expression of a given time and place, but rather, there are almost always multiple competing claims to expression of a given time or a given culture. That is an essential part of history, and we do ourselves no service by oversimplifying history to a neatly linear one-track scheme. Historians today acknowledge this complexity and multiplicity, and are focused on providing interpretive materials to allow viewers to sort out these complex and often competing narratives for themselves.

Where, then, did the impetus for this stylistic dictate come from? The answer is all too simple: from ideological architects, who believe that modernism (and its postmodern variants) is the one and only authentic architecture of our time. Curiously, it was also the architecture of the 1930s, 1950s, 1960s… and apparently, all future time too. One thing is certain: anything like revival or reconstruction of what existed before 1930 — or even any new construction building on traditional pattern and precedent — is a cardinal sin.

This philosophy was perfectly summarized by the enormously influential Athens Charter, purportedly the outcome document of the 1933 Congrès Internationaux d’Architecture Moderne conference, but written mostly by the architect Le Corbusier and published a decade later. Here is Le Corbusier’s pronouncement, in Article 70 of the Charter, on new construction in historic contexts:

The practice of using styles of the past on aesthetic pretexts for new structures erected in historic areas has harmful consequences. Neither the continuation of such practices nor the introduction of such initiatives will be tolerated in any form. Such methods are contrary to the great lesson of history. Never has a return to the past been recorded, never has man retraced his own steps. (Emphasis added.)

Anyone acquainted with architectural history knows that this is, of course, the sheerest nonsense. Never has a return to the past been recorded? The Renaissance did not happen, Jefferson did not recapitulate Palladio, did not recapitulate Vitruvius, did not recapitulate the Greeks? Le Corbusier’s is a simpleton’s view of history, a single straight line in which everything moves forward, always forced to be new, always different.

We can be thankful that history is far richer and more complex, and that it exhibits the ready capacity to compound, to learn, and to evolve over time. Like natural systems, our human systems are able to build on what came before, not simply discarding it (in the modernist Walter Gropius’ tart phrase, “starting from zero.”) A biological analogy for that severe restriction might be that evolution may not use the rich genetic material of pre-existing organisms, but must always start over again with, say, amoebas.

But among architects, the 1933 Charter of Athens was a profoundly influential document, and it is difficult to over-state the impact it has had on the human environment ever since. Its application has been profoundly negative, as many scholars have documented. The idea that everything must be radically new, must be stripped of all ornament, must avoid ALL associations with the forms and patterns of the past — the enormity of that restriction is hard to grasp. Again to use an analogy from genetic evolution, this would be like saying to a dolphin, “your dorsal fin looks far too much like a shark’s, yet you are from 300 million years later — that fin design is old, outdated, and traditional, and therefore it has to go!” Perhaps the dolphin might adopt a swoopy fin too…

Those who are not associated with the architecture profession, as we are, might find it bizarre, then, that such an ill-considered ideology shapes human society, to this day. As one theorist observed, “modernism’s alchemistic promise, to transform quantity into quality through abstraction and repetition, has been a failure, a hoax: magic that didn’t work.” And yet this outmoded ideology, almost a century old, persists in some corners, as we see now. It persists in the status quo thinking of many architects and even some officials and members of the public — and it even persists in some legislation.

One place where this ideology persists is in the 1964 Venice Charter on the Conservation of Monuments and Sites, used by many governments to shape their legislation regarding conservation. Modernist architects are fond of quoting Article 9, which calls for new work to “be distinct from the original composition and must bear a contemporary stamp.” They interpret this article to mandate a “contemporary design”, i.e. a modernist or neo-modernist insertion. But a 2006 conference of heritage and conservation professionals concluded that the goal of legibility is only one goal, which needs to be considered in relation to others:

This goal must be dynamically balanced with other needs, including the need for coherent and enduring human environments. Thus, new work may be distinct from the original composition while still harmonizing with that composition. A contemporary stamp may be provided in a number of ways, including interpretive information or identifying marks or characteristics. It is not necessary to create a striking juxtaposition, which may violate the mandate to preserve the traditional setting or the relations of mass and color [as called for in Article 6].

This is a crucial point that is conveniently overlooked by modernist ideologues. Most importantly, Article 6 of the Venice Charter flatly states:

Wherever the traditional setting exists, it must be kept. No new construction, demolition or modification which would alter the relations of mass and color must be allowed. (Emphasis added.)

This article flies in the face of the mandate for “contemporary” insertions, which often violate the scale, mass, form, color, etc. (The crucial question not usually asked: why this stubborn insistence on breaking every form of harmony?) Article 6 also clearly opens the door to sympathetic new construction in a similar traditional form that acts to “preserve the traditional setting” and the “relations of mass and color” — assuming that the new work can be differentiated through some kind of “contemporary stamp”. This could be literally – as in the photo below –  a date stamp!

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This building in a traditional character, located in the historic Nob Hill District of Portland, has a literal date stamp on its front showing its construction in 1992.  No one would be fooled as to its historic origins. (Image: Google Maps.)

It must be noted here that, although the current standard is an EU one, this is not merely a European problem. After all, Europe has historically been enormously influential in imposing its urban and architectural theories on  the rest of the world, not least in its invention of the modernist “International Style.” The decision-making economic/political classes in other countries are unfortunately still swayed by these ideologies, as evidence shows – to the great detriment of local architectural and urban cultures. This is all the more ironic since, having ousted former colonial powers, many national governments continue to uncritically follow fashionable ideologies from power centers elsewhere.

The broader issue is this: will non-architects, and others not specialists in conservation, continue to allow an outmoded century-old ideology to cause the degradation of cities, even (especially) in their most historic and most beautiful cores? Or will we see a continued (and increasing) uprising of citizens, activists, non-architect professionals, and other concerned leaders, demanding that architects and other specialists raise their game, and create a new generation of more humane, more historically rich human environments? The current controversial standard poses an important and timely test of that question.

The full EU proposal can be viewed here:

An ongoing series of essays updating notions of historic preservation and heritage for our times is published by the National Trust for Historic Preservation:

Building Tomorrow’s heritage. I. What historic structures can teach us about making a better future

Building Tomorrow’s Heritage. II. Lessons from Psychology and Health Sciences

Building Tomorrow’s Heritage. III. Correcting “Architectural Myopia”

About the authors: Michael W. Mehaffy received his Ph.D. in architecture at Delft Technical University and has had five appointments in university architecture departments in five countries. He is currently a senior researcher with the Centre for the Future of Places at KTH Royal Institute of Technology in Stockholm. Nikos Salingaros is a professor of mathematics and architecture, and an award-winning architectural theorist

Wonders of the “urban connectome”


Cities, like brains, are immense networks of connective patterns built up over time. Understanding this evolving structure will help us to formulate better urban policies and practices.

Few developments in the sciences have had the impact of the revolutionary discoveries in genetics, and in particular, what is called the “genome” – the totality of the complex pattern of genetic information that produces the proteins and other structures of life. By getting a clearer picture of the workings of this evolving, generative structure, we gain dramatic new insights on disease processes, on cellular mechanisms, and on the ultimate wonders of life itself. In a similar way, geneticists now speak of the “proteome” – the no less complex structure of proteins and their workings that generate tissues, organs, signaling molecules, and other element of complex living processes.

An important characteristic of both the genome and the proteome is that they work as totalities, with any one part potentially interacting with any other. In that sense, they are immense interactive networks, with the pattern of connections shaping the interactions, and in turn being shaped by them. Proteins produce other proteins; genes switch on other genes. In this way, the structure of our bodies evolves and adapts to new conditions – new infections, new stresses, new environments.

It turns out that something very similar goes on in the brain. We are born with a vastly complex pattern of connections between our neurons, and these go on to change after birth as we experience new environments and learn new skills and concepts. Once again, the totality of the pattern is what matters, and the ways that different parts of the brain get connected (or disconnected) to form new patterns, new ideas and pictures of the world.

Following the naming precedent in genetics, this structure is now being called the neural “connectome” (because it’s a structure that’s similar to “genome”) and the race is on to map this structure and its most important features. (Much of this work is being advanced by the NIH’s Human Connectome Project.)

What do these insights have to do with cities? As Steven Johnson noted in his book Emergence, there is more in common between the two structures than might appear. There is good reason to think that, as with brains, a lot of what happens in cities has more to do with the overall pattern of connections, and less to do with particular elements.

As Jane Jacobs pointed out over half a century ago, the city is a kind of “intricate ballet” of people interacting, going about their plans, and shaping the life of the city, from the smallest scales to the largest. This intricate pattern is complex, but it’s far from random. As Jacobs argued, it exhibits a high degree of order — what she called “organized complexity.”

And it’s physical, starting at the scale of the sidewalk, and encompassing all the other movements and connections of urban activity. “Sidewalk contacts are the small change from which a city’s wealth of public life may grow,” she wrote. We may also be plugged in electronically by telephone and now Internet, but (as research by Robert Putnam and others is showing) the root of the system is the physical proximity with the people we know and work with.

More than that, this pattern of connections generates remarkable efficiencies, forming a kind of “network metabolism.” Jacobs has since become famous for observing highly local “knowledge spillovers,” casual transfers of knowledge about a job or a new tool or idea, that help to grow new enterprises and new economic activities. Her insight, now called a “Jacobs externality” by economists in her honor, helps to explain how a city generates wealth. As we have written before, this phenomenon might well help to explain why cities are so efficient with resources per person, relative to other places.

In the same vein, the brain scientists offer some other important insights. For one thing, more important than the density per se (of neurons, or of people) are the patterns of connections. So we have to be able to ensure that many “neural pathways” can form and re-form – in the case of a person’s brain, that the person is healthy and well-nourished enough to remember, and learn. In the case of cities, we have to ensure that we have well-connected, walkable cities, facilitating many cross-connections.

The brain scientists even believe now that this pattern of neural cross-connection is key to the formation of consciousness. In effect, the different parts of the brain join up into a larger system, and the result is that the system self-organizes into a state that is smarter and more aware. When a brain sleeps, this larger pattern seems to dissolve into fleeting sub-patterns – and we experience the loss of consciousness, and sometimes, dreaming.

Something similar might be going on with well-connected cities: they can self-organize to become “smarter” in their ability to generate great urban vitality with fewer resources. But this is true only if their “neurons” (the people) are able to be connected, especially physically connected, in this way.

Similarly, a city can “lose consciousness” by becoming too fragmented and too sprawling. Automobiles and other machinery can help to connect the parts of the city, but only in a very limited and encapsulated way. By contrast, a walkable public realm has vastly more capacity to form and re-form connections between people, allowing a dynamic pattern of interaction to form and sustain across the city’s urban fabric.

This lesson of self-organization carries an important implication for planners and urban designers. It suggests we need to focus less on the specific elements in relation to one another – and how we might imagine they are best placed – and focus more on how we can help them to self-organize into more complex (and more efficient) patterns.

On the other hand, human brains do not start from scratch as we once thought, nor do societies – we all have patterns that we learn and apply to new situations. So too, cities have patterns that facilitate this network structure. Like a good memory or innate knowledge, the best walkable cities of history offer us many good reusable patterns to create vibrant, walkable, resource-efficient cities.

A corollary is that in our automobile-connected suburbs, it seems we have been replicating this pattern of connections – but only with heavy and unsustainable inputs of resources. Furthermore, as noted before, the structure of encapsulated cars, and existing networks of people we already know, are no match for the open-ended nature of public space networks, and their capacity to exploit “propinquity and serendipity” – the accidental connections with people we don’t already know, where, as research shows, the new knowledge and innovations form. If we want more resource-efficient cities – and more creative and resilient economies – then it seems we will have to look much harder at this dynamic, and ways to exploit it to our advantage.

How can we do this, concretely? The brain scientists are working hard to map the connective patterns of particular brains, to get some idea of how the patterns tend to form characteristically within the “human connectome.” For cities, it seems we might do something equally useful: map the characteristic urban patterns that have proven most conducive to this connected vitality, and that also do not interfere with – or better yet that promote – the capacity for urban self-organization.

In a sense, we already do this when we speak of design types, or planning models. But this work is usually very constrained by parochial debates within the architecture and urban design disciplines over “progressivism” versus “historicism.” The result is that there has been a stagnation of real progress in this area. At worst, we have slipped into what Jacobs called a “neurosis” of “imitating empiric failure, and ignoring empiric success.”

By contrast, the brain scientists point to another, less ideologically constrained path. It seems we might have much to learn from a more open, aggressive mapping and re-applying the genetic patterns of such an “urban connectome,” looking at the most effective patterns from a range of cities around the world – and over centuries of evolution.

LSE researchers: beware of the “build baby build” approach


“Upzoning is far from the progressive policy tool it has been sold to be. It mainly leads to building high-end housing in desirable locations.”

As this blog has long argued, the challenges of affordability, equity and sustainability are complex, and require a comprehensive approach, including economic tools, “polycentric” regional planning, and other strategic interventions.  These challenges are not likely to be addressed with simplistic “silver bullets.”  Case in point: the idea that just building more supply (especially in the cores) will automatically result in lower prices, more opportunities for formerly excluded populations, or more sustainable urban types.  (What some have called a “build baby build” approach.)

In recent research discussed on the CityLab blog, economic geographers Andrés Rodríguez-Pose and Michael Storper of the London School of Economics found that “Upzoning expensive cities is no match for the deep divides within—and especially between—cities, and is wholly insufficient to remedy them.”

The research by LSE is hardly the first to point out this problem with “build baby build”.  As the CityLab article points out, “Economist Tyler Cowen agrees that the ultimate beneficiaries from zoning and building deregulation are landlords and developers. As he puts it, “the gains from removing taxes/restrictions on building largely will be captured by landowners … More stuff will be built, urban output will expand, land still will be the scarce factor, and by the end of the process rents still will be high.”And a recent study by Yonah Freemark found that upzoning in Chicago led to higher, not lower, housing prices, while having no discernible impact on local housing supply.”

The author of the CityLab article, Richard Florida, expressed dismay at the barrage of derogatory criticism that he and the LSE economists received from defenders of the “build baby build” approach.  “That makes little sense,” said Florida. “The paper is an important cautionary tale. The authors are not saying that we should not build more housing. They are simply saying that doing so won’t magically solve economic and spatial inequality, because both are deeply rooted in the very nature of the geographically clustered and concentrated knowledge economy.”

But perhaps the effects of financial and other self-interests are far more seductive than the calm and reasoned approaches that are called for.  Perhaps the lesson here is the one famously offered by Upton Sinclair: “It is difficult to get a man to understand something, when his salary depends upon his not understanding it.”

Excerpts from the CityLab article are below, and the entire article can be read here.

new paper by two leading economic geographers suggests this argument is simply too good to be true. Titled “Housing, Urban Growth and Inequalities” and forthcoming in the journal Urban Studies, it’s written by Andrés Rodríguez-Pose of the London School of Economics (LSE) and Michael Storper, who divides his time among the LSE, UCLA, and Sciences Po in Paris. According to Storper and Rodríguez-Pose, the notion that an insufficient supply of housing is a main cause of urban economic problems is based on a number of faulty premises. They say the effect of supply has been blown far out of proportion.

They agree that housing is part of the problem: “Housing market failures can imperil local economic growth and generate problems such as segregation, long commute times, deteriorating quality of life, homelessness, and barriers to social mobility for certain populations,” they write. But housing policy, and zoning restrictions in particular, are certainly not the be-all and end-all of urban problems. Upzoning expensive cities is no match for the deep divides within—and especially between—cities, and is wholly insufficient to remedy them.

“Housing is an area where the law of unintended consequences is most powerful,” Storper recently told Planning Report. “The idea that upzoning will cause housing affordability to trickle down within our metropolis, while also setting up Los Angeles and San Francisco as the new golden land for people in less prosperous regions, is just a lot to promise—and it’s based on a narrative of housing as opportunity that is deeply flawed.” And as Rodríguez-Pose told me via email: “Upzoning is far from the progressive policy tool it has been sold to be. It mainly leads to building high-end housing in desirable locations.”

Rodríguez-Pose and Storper question several pieces of evidence that stand at the heart of this market-urbanist view, a perspective they dub “housing as opportunity.” Whereas some urban economists suggest a close relationship between housing supply and prices (with places that add supply having lower prices), Rodríguez-Pose and Storper find the relationship to be weak.

Likewise, some market urbanists point to an association between city population size and/or density and economic growth. But Rodríguez-Pose and Storper argue that this too falls away under close scrutiny—the link between city population in 2000 and subsequent economic growth from 2000 to 2016 is weak to “non-existent,” on their analysis.For Storper and Rodríguez-Pose, the rising spatial inequality between cities and metro areas stems from different kinds of economies that distinguish different kinds of cities, not from differences in housing costs. Or as they put it, “the basic motors of all these features of the economy are the current geography of employment, wages and skills.”  

The economies and talent bases of cities have diverged over time. Expensive cities have much larger clusters of leading-edge tech and knowledge industries and of highly educated, skilled talent. It’s this, rather than differences in housing prices, that is behind growing spatial inequality.

“The affordability crisis within major urban areas is real,” they write, “but it is due less to over-regulation of housing markets than to the underlying wage and income inequalities, and a sharp increase in the value of central locations within metro areas, as employment and amenities concentrate in these places.”

A key factor here is the growing divide between highly-paid techies and knowledge workers and much lower-paid people who work in routine service jobs. These service workers end up getting the short end of the stick, spending much more of their income on housing in expensive cities. “Under these circumstances moving to big cities provides no immediate benefits for workers without college education,” Rodríguez-Pose and Storper write.

Upzoning does little to change this fundamental imbalance. Because land in superstar cities and tech hubs is so expensive to begin with, upzoning tends to create even more expensive condominium towers. “While building more affordable housing in core agglomerations would accommodate more people,” the authors note, “the collapse of the urban wage premium for less-educated workers means that the extra housing would mostly attract additional skilled workers.”

Opportunities for improved wages in core areas have stagnated, and the “ladder has shrunk.” Therefore, the decline in interregional migration can be attributed to many factors, including the new geography of skills and wages. But housing restrictions in prosperous areas wouldn’t top the list. And upzoning ends up fueling, not relieving, economic and spatial inequality. As Rodríguez-Pose told me: “Income inequality is greater within our cities than across our regions. Upzoning will only exacerbate this.”

“Planning deregulation and housing costs are neither going to solve the problem of areas lagging behind, nor are they likely to have an impact on the economic development of dynamic cities,” Rodríguez-Pose and Storper write. Worse, they caution, “an excessive focus on these issues at the expense of serious and sustainable development strategies, can fuel economic, social and political distress and anger in declining and lagging areas that can threaten the very foundations on which economic activity, both in less developed and more prosperous areas, has been erected in recent decades.”


This last point deserves attention.  By focusing on a kind of “voodoo urbanism” approach — by concentrating too much on the urban cores, including new building there, and hoping the benefits will “trickle down” to everyone else — we are not only not improving the affordability and equity issues, we are actually fueling a spiraling dynamic of “left-behind places.” These  include the suburbs, and also, importantly, the smaller towns and rural areas where much of the so-called “populist revolt” is occurring (in both the US and other countries).  Rodríguez-Pose in particular has argued for a more evenly distributed, “polycentric” approach to economic and human development, within city regions as well as national regions. 
 To us this suggests a more even-tempered and polycentric approach to development across urban and national regions —  creating a network of walkable, compact, transit-served places at a range of scales, densities, and (importantly) costs.  As we have written before, this approach might be thought of as a kind of “Goldilocks urbanism”.  Yes, cities do generate economic and cultural benefits from concentrations of talent, but also from “spreading it around.” Getting the balance “just right” (neither too hot nor too cold) is not just about fairness; it turns out to be better for everyone’s bottom line too.  

Why “cities of opportunity” need well-connected public space systems

A night market in Hong Kong, providing opportunities for economic transactions and social mixing along a busy street.

“Cities of opportunity” – the theme of the 2020 World Urban Forum – reminds us how cities facilitate connections between diverse people and resources. thereby generating opportunities for all to develop and prosper, in economic, health and cultural dimensions. Public spaces are emerging as the essential platform on which these connections between people and resources develop. New research shows that public spaces are supplemented by, but not replaced by, other more private forms of contact, which tend to reinforce already existing connections. By contrast, public spaces play a role in “propinquity and serendipity” which are emerging as key drivers of innovation and opportunity. Cities for all, by definition, must offer public space (including streets and other spaces) for all. An important research question is, then, what is the role of public space in fostering innovation, creativity, and opportunity for all? What is its role in promoting resilience and climate adaptation?  And what tools and strategies can we use to achieve these goals?

The New Urban Agenda contains nine paragraphs describing the importance of public spaces. Among the benefits identified are social interaction and inclusion, human health and well-being, economic exchange, cultural expression, improving resilience of cities to disasters and climate change, physical and mental health, household and ambient air quality, reducing noise, promoting attractive and livable cities [and] human settlements, and prioritizing the conservation of endemic species.

These goals are all the more important in an age of rapid urbanization, growing climate stresses, surging informal settlements, threats to the well-being of vulnerable populations including migrants, growing urban inequality in many cities, and increasing trends of urban sprawl and fragmentation, resulting in the degradation or loss of public space. Yet it is public space that is most helpful in responding to these challenges, as the New Urban Agenda makes clear.

The adoption of the New Urban Agenda by acclamation by all 193 member countries of the United Nations stands as a landmark achievement in urban history. However, that achievement must now be followed up by implementation – by the sharing of tools and knowledge about how to develop, protect and improve public spaces, and public space networks. Much progress has been made, but further progress depends on further sharing of knowledge and tools.

The Future of Places and its allies will be attending the World Urban Forum, and hope to see many friends and collaborators there.