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by Joost de Bont (visit profile page), 22 September 2015
Coping with Informality - A Short History of Slum Development in Latin America
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Metro Cable at San Agustin, Caracas, Venezuela ©Iwan Baan


We live in the urban era. In the year 2009 the scales tipped and the majority of the world's population is now reported as living in urban areas. Less studied is the significance of slum development during this same period. This is an issue whose importance to the well being of city dwellers cannot be over-stated in the history of modern urbanization. About one-third of the people in cities currently live in slums. In the future, this will become even more significant as slums will constitute the largest part of urban growth. For 2050 it is predicted that 3 out of the 7 billion people living in cities will live in self-built neighbourhoods.1 Slum development is essentially the phenomenon of people building their own houses mostly outside the control of any state or law. It is also called informal urbanization, for it is a form of city production that acts outside the formal frameworks. These informally-built settlements go by many different names, some of which may sound familiar: favelas, barrios, barriadas, bidonvilles, piratas, shanty towns, and townships to name just a few. Informal urbanization is seemingly an inevitable by-product of the production of space and cities all over the world. This article is not intended to provide clear-cut answers and may even leave behind more questions than answers. The world is complicated and ambiguous and the issue of informal urbanization even more so. This discussion aims to provide some insights on the background of the slum development phenomenon and some examples of how it has been addressed in recent decades.

This text focuses on Latin America for several reasons. First, the continent is a front-runner in terms of urbanization in the Global South (the so-called developing world in the southern hemisphere). With about four fifth of the population living in cities, it is extremely urbanized compared to Asia and Africa were the urban population accounts for less than a half of the people. To a great extent, this is the result of urban migration waves that have taken place in much of Latin America from the middle of the twentieth century on. Informal development has always gone hand-in-hand with urbanization. As a result, Latin America has already experienced some of the informal urbanization issues that Asian and African countries have yet to face.  The second reason for writing about this continent is simply that it is the one in the Global South that I know the best. I’ve visited and studied various informal settlements in this part of the world, most notably in Venezuela and Colombia, for the last 4 years.  A final reason for selecting this continent is poetically expressed by French psychoanalyst and philosopher Félix Guattari:  “Latin America is Africa, Asia and Europe at the same time”. 2

Like other continents in the Global South, informal urbanization in Latin America is a direct result of formal systems' (read governments and later private developers) lack of capacity to deal with the rapid growth of the urban population. All around Latin America, governments were "building housing estates that were tokenistic compared to the scale of the proliferating slums".3 However, the crucial issue for informally-built settlements is not merely their existence, but how they are perceived and dealt with. Landscape architect Christian Werthmann researched various non-formal cities in Latin America and the implementation of infrastructure in these emerging cities at the Harvard Graduate School of Design. He identified five stages in which societies tend to address informal development, namely: denial, eradication, tolerance (admiration), improvement, and anticipation.4 Historically, these have not always been chronological phases. For example, in some places informally-built settlements may be tolerated while elsewhere their existence is denied.

Part of the denial of slum existence is an attempt to keep the difficult living conditions within these neighbourhoods under the radar. The existence of these areas was, well into the 20th century, invisible on most official city maps. This was a result not only of the difficulty of mapping these impassable and densely constructed networks, but also a political choice. For instance, maps of Carácas (Venezuela) from a few decades ago map barrios (slums) simply as zonas verdes (green zones). This phase has not yet fully passed, as even today slums are "often omitted from official maps and documents and frequently physically hidden by local authorities by colorful walls and fences".5 For this reason, informal settlements are often referred to as the 'invisible city' or even the 'denied city'.6 Other attempts to make these parts of the city invisible resulted in government-initiated slum clearance. The phase of eradication is possibly worse than that of denial because it not only destroys physical structures, but also the socio-cultural structures embedded in them. Examples of slum evictions are endless, from well planned and official ones up to entire favelas that are burned down. In São Paulo, for example, seemingly accidental fires, were presumed to be caused by criminal groups paid by real estate developers.7 Another example is the Torre de David in Carácas, a 196 meter high squatted tower that became famous through various research publications and appearances in TV shows (e.g. Homeland). In 2014, the government evicted the thousands of inhabitants that had built up their own homes within the tower.8

But it is not all doom and gloom. In recent decades some intervention strategies have been developed that deal with the informally-built city in a different and innovative way. These visions emerged from the phase that Werthmann called tolerance / admiration. One of the first steps made within this phase is be the work done by British architect John Turner on the barriadas of Lima (Peru) in the 1960s. In his book Radical Cities, critic Justin McGuirk revisits the work of Turner and explains the importance of it, namely the revelation of this phenomenon we call informal urbanization. By describing the case of Lima, where about 70 percent of the people at the time lived in self-built structures and "were managing to house themselves", Turner took a critical position.9 He even went further, almost romanticizing the idea of the self-housing, when he stated that "'the barriadas are, undoubtedly, the most effective solution yet offered to the problem of urbanization in Peru".10 As a provocation, this could be a productive standpoint, but if taken too far we risk overlooking that informally built settlements offer far from perfect living conditions. Many times running water, sewerage, (safe) access to electricity, (high quality) public space and amenities, and stable housing conditions lack. Turner's admiration continues in the temporary discourse on slums. Alfredo Brillembourg, co-founder of Urban-Think Tank, described the slums that he worked in as a green sustainable 'utopia': "the car-free city, the dream of every architect".11

This being said, it must be admitted that these provocateurs freed the way for policy makers, planners, and architects to think about and develop plans to actually improve conditions in slums. What follows is a condensed history of Latin American slum upgrading practices. In the improvement phase, plans come in different forms and scale levels. From artists repainting an entire favela with its residents to the development of public infrastructure in the form of cable car systems. The latter turned out to be the innovative approach to implement public transport into favelas, barrios and piratas on the hillsides of the cities of Rio de Janeiro, Carácas, and Medellín (Colombia). The infrastructure project in Medellín is especially interesting since it was combined with building public amenities such as libraries and schools in the middle of these precarious neigbourhoods.12 Some of these buildings even became photogenic icons of the city, like the Biblioteca España in the Santo Domingo neighborhood, designed by el Equipo de Mazzanti. What makes all this so impressive is that the improvement projects are all part of a long term and city-wide strategy with a political mandate that overcomes the terms of just one or two mayors. This long-term approach is unfortunately still very rare in most countries dealing with informal urbanization.


Espacios de Paz, Petare
Espacios de Paz, Petare, Caracas ©PICO Estudio

These top-down projects require immense public support and are obviously very capital-intensive. They are not the only way to improve the built environment in slums. Also designed by el Equipo de Mazzanti is a low-cost roof structure for a community in the Cazucá neighborhood in the periphery of Bogotá. The canopy, while 'just a roof', is now used in a variety of ways from church to sports centre and from dance floor to cultural centre.13 In Carácas a wide range of projects was initiated under the name Espacios de Paz (Spaces of Peace).14 Local inhabitants of barrios developed these interventions together with a group of international architects and students in a participatory building process. The interventions not only physically transformed the built environment, but also improved social cohesion. By making use of available "self-building techniques" places mostly seen as conflictive urban territories were turned into useful public spaces. Some examples of these interventions are "basketball courts located on a rooftop, spaces for learning and debating, playgrounds, amphitheatres, viewpoints, and so on".15

Werthmann's final phase is that of anticipation, which brings us back to the work of John Turner. His published writings and studies had an impact when in the late 1960s an experimental housing competition named PREVI was launched to house people from the barriadas in Lima. The result was a neighborhood of 500 houses designed by the likes of James Stirling, Aldo van Eyck, the Metabolists, Charles Correa, Christopher Alexander, and Candilis Josic Woods;16 an 'all-starchitects' team. What is striking about the dwellings designed for the PREVI neighbourhood is that they were intended to be extended over time, just like the houses in informal settlements. As a result, the buildings nowadays are unrecognizable as design works of the original architects because they have been extended and modified to fit the demands of their inhabitants. This turned out to be a very successful approach. The residents that have remained there from the project's inception consider themselves very lucky to live there.17 The only minor downside was the fact that the project was intended to create repeatable prototypes, and these never actually happened. The actually built projects were too diverse and many times expensive to make repetition possible. Cost effective replication of the different designed social housing projects was not considered to be a viable option here. About four decades later, the idea of designed incremental housing solutions found more fertile ground in Chile. Alejandro Aravena's office Elemental managed to design houses that could be extended by their inhabitants and be constructed much more inexpensively than regular social housing projects. The concept was simple: "half a good house is better than half a house".18 In other words, building the half of the house that is more complicated for the people themselves to build (services such as bathroom, kitchen and toilet) allows the remainder of the construction to be built for a lower price by the people themselves. By providing a framework for extension, an incremental solution, the informal is not entirely formalized but supplied with a steady basis.


"Half a good house is better than half a house" - Quinta Monroy Housing, Iquique, Chile ©Elemental


Coming from a time wherein informal urbanization was mostly neglected, denied or (maybe even worse) eradicated, big steps were made in dealing with this phenomenon in the last few decades. The discourse moved from sometimes naive admiration of informally built settlements to an adequate assessments of these parts of the city. By looking both at the challenges and the opportunities at hand in these communities new effective and innovative solutions were developed. There are way more challenges ahead, since informal urbanization is an ever growing phenomenon and new answers have to be found. We have entered the era of slum improvement, next step is the era of anticipation.

This essay was written based on many insights and conversations from Maarten Kempenaar and Josiena Simonian, who co-organized a symposium (in)formality Wanted at TU Delft.



  1. Werthmann, C.  (2011) Metropolis Nonformal Towards a Global Design Exchange [lecture slides].

  2. Guattari, F. and Rolnik, S. (2006) Micropolítica. Cartografías del deseo. Madrid: Traficantes de Sueños, p. 346.

  3. McGuirk, J. (2014) Radical Cities. Across Latin America in Search of a New Architecture. London: Verso, p. 51.

  4. Werthmann, C.  (2011) Metropolis Nonformal Towards a Global Design Exchange [lecture slides.

  5. Argentino, M. T. and Flores, C. (2003) Slums of the World: The face of urban poverty in the new millennium?. Nairobi: UN-HABITAT, p. 6.

  6. Ibid.

  7. Domingues, V. (2012) ‘Favelas e Especulação’, in: Observatório de Favelas.

  8. Velasco, M. and de Bont, J. (2014) ‘Torre de David‘, in: Architecture in Development

  9. McGuirk, J. (2014) Radical Cities. Across Latin America in Search of a New Architecture. London: Verso, p. 51.

  10. Ibid., p. 52.

  11. Ross, P. (2014) ‘Climate Change Solutions: Architects Look To Slums As Models For Sustainable Living’, in: International Business Times.

  12. de Bont, J. (2014) ‘Building for Change’ in: Architecture in Development.

  13. Ibid.

  14. García Alcaraz, T. (2015) ‘Creating Spaces for Peace, Dialogue and Coexistence in Venezuelan Cities’, in: This Big City.

  15. Ibid.

  16. McGuirk, J. (2014) Radical Cities. Across Latin America in Search of a New Architecture. London: Verso, p. 53.

  17. Ibid., p. 56.

  18. Aravena, A. (2014) ‘My architectural philosophy? Bring the community into the process’[video], in: TED.