This article originally appeared in the book The SANAA Studios 2006-2008, Learning From Japan: Single Story Urbanism, Florian Idenburg editor, Princeton University and Lars Muller Publisher, 2009. A brief review in Metropolis can be found here.
Genchiku is a Japanese neologism meaning, roughly, “reductive construction.” It belongs to the same realm of paradox wherein lies the bigness of shrinking Japan, and the culture of newness hiding the nation’s aging population. And genchiku puns nicely with the word for architecture, kenchiku.
Architect Hidetoshi Ohno explains genchiku in the catalog for the 2000 exhibition Towards Totalscape: “Until now building more has meant increasing value. But we are starting to see that building less can increase value too.”  Increasing value while decreasing production necessitates creating new polyvalence and hybridizing old use, strategies that are being deployed in the architecture and urban policy of aging, depopulating Japan. If one thinks of the Japanese economic engine of the 1950s through 1980s as a producer of rampant, predominantly characterless, market driven, kenchiku - in a nation where 20%twenty percent of GDP comes from the construction industry - then in the post-bubble, post-max age, genchiku is an appropriate new mode for the built environment.
In 2005, Japan became the first large industrialized nation to experience population decline attributable entirely to natural causes; more people are dying in Japan than are being born, without the presence of war, epidemic, or migration. By all recent projections, depopulation will be the default condition in most of the developed world by the next quarter-century, but Japan has reached this watershed before any other nation. Depopulation on this scale is accompanied by societal aging as the conventional population pyramid is turned on its head. How Japan responds to aging and downsizing will serve as a bellwether for industrialized nations, and implications for the built environment are vast.
Through the economic crash that precipitated the 1990’s “lost generation,” Japan’s great megalopolises, have remained stable or increased in density, while many smaller cities – particularly those dependent on disappearing industries, began to fade away. Municipalities caught in the middle, the peripheral “bed towns,”, newly minted suburbs, and mid-sized semi-agricultural agglomerations, were also condemned to shrink and possibly disappear entirely.
In the wave of introspection that followed the bubble, the government reappraised the laisser-faire, top-down national “consensus” that powered Japan through the latter half of the twentieth 20th century; now a locally-driven neo-liberal model has emerged. Individual regions, cities, and municipalities have been set in competition with each other. The result is emerging genchiku urbanism, as agglomerations of all sizes are assessed by new standards of viability, amenity, and convenience that encourage both scaling back and up-scaling.
On a regional scale genchiku can be seen in trends of consolidation, as municipalities with high debt, shrinking populations, and poor tax bases merge with more robust neighbors. From 2005 to 2007 the number of autonomous cities, towns, and villages in Japan shrunk from 2190 to 1,822.  In a country whose citizens tend to be emotionally invested in local social support systems, consolidation has had profound effects on the collective psyche. In towns that have nominally disappeared, communities have lost their identity.
Locally, genchiku can be the result of the push to hone the identity of a city or town, making it more attractive by developing its culture while downplaying and reworking its voids. In the most ambivalent communities this might result in something as banal as a newly conceived town motto, while the more successful cases create new value through core redesign, investment in attractor enterprises, and cultural projects.
Finally, on the scale of the street genchiku can take on another meaning, implying a form of gentrification as wealthier households merge multiple units to form larger homes. Still, this type of gentrification is a break from past practices, when developers sensing a market shift would destroy perfectly good housing to respond to the new demand. “For a hundred years, we’ve played at architecture as a kind of expensive hobby, tearing down and rebuilding buildings sometimes before they were paid for,.” Ohno writes, “But this becomes less and less feasible as the population ages. Now a quarter of the population is over 65 and another quarter is constituted by minors. A society where one half the population supports the other half is much less productive...When you don’t have the extra resources any more buildings stick around longer.” Rehabilitating the old, in a society where youth and newness is virtually a religion, is a project indeed.
Ageing Up, Not Out
"It seems possible that a society in which the proportion of young people is diminishing will become dangerously unprogressive, falling behind other communities not only in technical efficiency and economic welfare, but in intellectual and artistic achievement as well." - 1949 Report of the Royal Commission on Population, United Kingdom
The Japanese economic miracle of the late 20th twentieth century was driven in part by artificial demographic manipulation in the pre-war and immediate post-war years. Going into World War II Japan was newly industrialized, virile, beholden to Nationalism, and questing for an empire. A population boom ensued, encouraged by government sloganeering: “let’s give birth, let’s increase!”.  While WWII leveled Japan’s industrial complex, the children of the pre-war boom lived on, creating a short-term overabundant population of dependants in a society that had just lost many of its most productive members. In 1948-49, the government launched an initiative to suppress Japan’s birth rate, cutting Japan’s post-warpostwar “baby-boom” to the four years between 1945 and 1949. The result was a population “trough” in the late ‘40s and ‘50s that, in following the earlier pre-warprewar peak, created a wave that would reverberate into the coming decades. 
In 2008, the crest of that wave is a population of healthy, long-lived citizens over sixty. Japan’s surge in life expectancy was a product of rapid economic growth that created rising incomes, healthier lifestyles and diets, and improvements in medical care. But the demographic tilt created by a healthy, aged, boom population has resulted in a steady decrease in the overall working-age population. As the “company men” of the bubble economy take their retirement, and live well beyond their projected life spans, Japan’s shrinking workforce must support an ever-increasing number of aged dependants.
Decades of laissez-faire government have fostered a robust tradition of local self-reliance in the typical Japanese municipality. Citizen membership in local organizations is nearly universal, and it is at this level that we see many of the more successful responses to the shrinking, ageing society. Identifying and capitalizing upon a municipality’s unique characteristics and turning those into a “brand” is now a strategy at the most local level. The town of Kamikatsu is a successful example. Located in Tokushima Prefecture on the island of Shikoku in south-west Japan; half the 2,200 residents are above the age of 65sixty-five. Yet local initiatives are remarkably cosmopolitan and innovative.
Embracing the latest in green technologies, Kamikatsu has put itself on the map in its quest to become Japan’s first “zero waste” town. Currently household waste is separated into thirty-four different categories to be recycled. That penchant for sorting is equally important to Kamikatsu’s leaf-and-flower-picking cooperative which supplies Japan’s garnish trade. The cooperative is staffed by 177 members of whom the average age is 70seventy. The business is Iinternet-based, and those same elderly operate both the front and back ends of the business, logging-in to take orders each day. 
The success of these initiatives help dispel the notion that the elderly cannot adapt or contribute meaningfully to the current economy, neither would these initiatives have been possible without robust local organization and the participation of a sizable number of Kamikatsu’s citizenry. This is a human resource form of genchiku: maximizing the usefulness of existing resources, and hybridizing uses. To increase the productivity of all working-age citizens, and extend that working-age to a level more appropriate for contemporary life -spans, requires rethinking dominant social assumptions.
Sociologist Chikako Usui proposes a blurred, irregular form of life-cycle that contrasts sharply with the former, Fordist model: “In the post-Fordist economy,” she writes, “workers will be more differentiated in terms of their skills, sequential careers, mixing of part- and fulltime work, and gradual retirement (as opposed to complete, one-step retirement). The traditional male career patterns will be “feminized,” with more chaotic career transitions throughout life. A life cycle in which adulthood is supported by a stable employment and old age begins with retirement will be replaced with intermittent employment, continuous educational training, and gradual retirement.” 
Building Down, Not Out
In 2003, the municipality of Onishi commissioned a new community center. Onishi is at the high water mark of the Tokyo Metropolitan Area’s expansion, just under an hour from the city center by high-speed train. As Tokyo retracted through the 1990s, Onishi became a shrinking tidal pool, one of many depopulating bedroom communities searching for its own identity and striving to remain attractive and vital. Onishi was merging with a neighboring municipality and its citizens feared an outright erasure of identity. The community center was a strategy to coalesce the local population and give Onishi a larger, global identity.
The resulting project, executed by SANAA, succeeds as both a branding exercise and a polyvalent local resource. The Onishi community center fights the condition of suburban dispersal by creating a magnet of activity in the center of a dying town. SANAA achieved this through their form of hyper-minimal, aestheticized “reductive construction” where transparent spaces frame both exterior and interior activity in a manner that unifies the site and its context. SANAA’s high profile in a nation that exalts material culture took care of the branding.
Taking the concept of genchiku as a multi-disciplinary way-finder, the Onishi community center stands out not as a reconstitution or recyclage but as a social concentrator. The best-case scenario for towns like Onishi is that such projects become magnets of value and amenity, strengthening local bonds and attracting continued interest in the town. But in the post-max, depopulating world, every successful Onishi, helps speed the creation of neighboring voids. Laila Seewang’s Onishi alternative – created in the SANAA studio at Princeton - accepts the inevitability of depopulation, anticipating and reconstituting the voids while recycling the abandoned excess.
Seewang’s proposal unfolds over thirty years. She describes it as a “reverse” architecture that “actively dismantles the unused fabric of the town.”. Seewang imagines a ribbon of “collection walls” that serve as both storage facilities for the recycled detritus of dismantled buildings and as “memento” niches for displaying the active memory of a town in slow disintegration. The project provides a collective emotional outlet for a situation in which there is no catharsis, the niches and their content are a substitute. At the same time the ribbon walls create a civic unity much in the same way SANAA’a transparent community center does, lending an infrastructure for constituent functions, the difference being that Seewang’s Onishi is programmed to become a beautiful ruin.
The city of Towada is another municipality negotiating its decline through genchiku. Situated well outside the urban agglomerations that belt Japan’s main island, Towada is four hours north of Tokyo by high-speed train. The city has suffered all the symptoms of an agricultural business center disappearing in the new economy. Too remote to be attractive to young professionals, Towada loses its youth to the larger cities, leaving a predominantly elderly population. In 2005, Towada merged with neighboring Towadako. Pooling their resources, the new entity created a cultural organization, “Arts Towada,” designed to reenergize Towada’s lifeless central business district.
From an initial project to fill empty lots and storefronts with an annual arts festival, Arts Towada has developed into a unique model for cultural “infrastructure.” Using a “dispersed gathering of white boxes” scaled and distributed in such a way as to encourage exploration and elaborate on the existing business district, Ryue Nishizawa has created a culture activator in a dying town. Each “box” is conceived of as a “house for art”, the scale of the volumes and the voids between merge with the exterior context. The art faces both in and out, and occupies interior and exterior, breaking out of the gallery spaces. The terrain of the project is as open as the central street itself, taking on the character of both a park and a street, a hybrid infrastructure that reorients the center of town.
While Arts Towada is built in an updated, minimal, modernist mode, the site plan, its rationale and its intentions are far from the Functionalist preoccupations of traditional Modernism. The organization is designed to attract local youth as well as place Towada on the global arts stage. The spaces are multi-purpose, serving as workshops, community meeting rooms, and activity centers. Florian Idenburg calls it a “settler camp,” merging the “global and local, cultural and civic” and posits, “when the rest of Towada has shrunk until all but the Art Center has gone, a beautiful little village will remain.” 
Japan’s dominant cities are in no danger of becoming “little villages” — whether beautiful or post-apocalyptic — any time soon. While population projections indicate substantial decreases as the century progresses the effect will by no means deurbanize Japan. The next generation will likely see consolidation as a by-product of the current dispersial. According to conservative estimates, by 2050 Japan’s population will be close to 100 million, dropping 17%seventeen percent in fifty years; less conservative estimates predict a fall to 80 million. 
Market analysts have long been predicting that the Japanese population vacuum would precipitate an international financial crisis. In 2002, Ken Courtis, then vice-chairman of Goldman Sachs, claimed that Japan would soon create the “largest economic crisis since the 1930s.”  However, recent events have proved that over-heated, as opposed to under-heated markets are a far larger threat, a lesson that could have been learned from Japan’s 1989 bubble-burst, which was in many ways a preview of the current worldwide economic crisis.
Likewise, dire warnings of the end of Japanese society as we know it are greatly exaggerated. In a nation famous for small cars and even smaller hotel rooms, whose citizens are adapted to very little elbowroom, the future can be considered healthy. Many Japanese who were priced out of cities and forced to endure long commutes from the suburbs are moving back towards the center as prices continue to fall, and the voids left behind as populations shift could be considered an opportunity to reclaim green space and regenerate an environment long lost to development. Indeed, seeing these trends as an opportunity and not a catastrophe will spell the difference between successful and unsuccessful policies.
To date the best initiatives have been activated at the local level, but networked globally. Architect Morika Kiro optimistically regards past transformations as the key to the future; suggesting that in the historical context of a nation that has twice recreated itself in the previous century, “...it is only natural that even today the Japanese both consciously and unconsciously believe that they have a choice to initiate political, social, and cultural transformations vast in scale.”  How Japanese society as a whole chooses to adapt will have intriguing implications at the global scale, as other nations begin to wrestle with these same problems. Architectural precedent in the form of genshiku’s “reductive construction,”, propagated by SANAA and like-minded practitioners, may be Japan’s next big export.
 Caroline Bos and Ben Van Berkel editors. Japan Towards Totalscape: Contemporary Japanese Architecture, Urban Design and Landscape. NAi Publishers, Amsterdam NL, 2001
 Consulate General of Japan, San Francisco. Consolidation of Local Governments in Japan and the Effects on Sister City Relationships, January 2006.
 Chapple, Julien. “The Dilemma Posed by Japan's Population Decline”, Electronic Journal of Contemporary Japanese Studies, 2004.
 Matsutani, Akihiko. Shrinking Population Economics, Lessons from Japan. International House of Japan, Tokyo, 2006.
 McCurry, Justin. “Climate change: How quest for zero waste community means sorting the rubbish 34 ways.” The Guardian UK, August 5, 2008.
 “The Demographic Dilemma: Japan’s Aging Society.” ed. Amy McCreedy. Asia Program Special Report. Woodrow Wilson International Center for Scholars, January, 2003.
 Florian Idenburg, “The Culture of Decongestion.”, Domus #915, January 2008
 Fujii, Yasuyuki. City Shrinkage Issues in Japan. Fuji Research Institute Corporation / Urban and Rural Issues. Mizuho Information and Research Institute, 2008.
 Fulford, B. “The Panic Spreads.” Forbes, Feb 18 2002.
 Bos, van Berkel