Slum, the Vernacular Architecture of Swelling Cities

The other way around

The slum phenomenon is so widespread that we may speak of a trend in architecture. The architectural debate will not go there often, there are no glossy magazines, no coffee table books and no architecture institutions which promote its design and style, but time is certainly ripe to look at the ways of building that provide housing to more than one billion people. This chapter is about the conditions under which slums arise, the place of this style in architectural theory and the relevance to the design profession.

Photo 1. Dharavi, Mumbai, India, nicknamed 'Asia’s largest slum'.

Slum develops during high urbanization. The influx of labour from the countryside to the city goes far beyond the housing and absorption capacity of the city. Industrialization is a powerful driver of urbanization. During the industrial revolution, many slums emerged in Western cities. In factory towns, people lived in high density under miserable conditions. This side effect of the industrial revolution was overcome by introducing legislation that set conditions on the quality of housing. In addition, many manufacturers took the initiative to organize a good home for their employees.

Violence is another major cause of migration. Besides the flow of migrants from rural to urban, migration of refugees is a major cause of slums. One difference between these two migrant groups is that people in the first group choose to migrate on a chosen moment, while the second group is at one time forced to leave, due to circumstances. This displacement results from natural disasters or human violence. Volcanic eruptions, floods, and wars drive people from their homes. If the house is not already destroyed, a life-threatening situation is reason enough to migrate. By its nature, the forced displacement of a refugee means that a part of the acquired property cannot be brought in the migration. In the hurry, refugees take all that can be taken. A rural migrant for that matter, has a better starting position. Possessions can be taken and acquired assets can be sold. The motive for economic migration is the lure of the city. Refugees act from the motive of expulsion.

A third stream of migrants that feeds slum formation, is caused by deportations. These forced migrations are actually a combination of the previous two forms. Under its segregation policy, the apartheid regime in South Africa forced many native Africans to leave their territory. They came up in townships like Soweto near Johannesburg and the Cape Flats in Cape Town. Under the same regime, many forced removals to the so-called ‘homelands’ took place, which have led to acute overcrowding.

In architecture, a distinction is made in style architecture and vernacular architecture. The latter is also known as folk architecture. Modern and progressive architecture are usually considered style architecture, whereas regionalism and traditionalism belong to the vernacular architecture group. Stewart Brand points out that, “in terms of architecture, vernacular buildings are seen as the opposite of whatever is ‘academic,’ ‘high style,’ ‘polite.’ Vernacular is everything not designed by professional architects – in other words, most of the world’s buildings.”1 This description covers slum architecture fully. Meanwhile, slum is a contemporary phenomenon that occurs worldwide. One might think it is a fashion phenomenon.

A much-quoted dictum of Henry Glassie states that, “a search for pattern in folk material yields regions, where a search for pattern in popular material yields periods.”2 Styles in architecture are often indicated by a period of a particular style in vogue. Victorian, Tudor, Romanesque, colonial. Periods can also be named after trends in philosophy such as Renaissance, Constructivism, Modernism, Postmodernism, and Deconstructivism. Vernacular architecture can be characterized by region. Vernacular architecture reflects the particular local conditions, materials, and techniques. The indication by region is an appropriate way to appoint the unique combination of circumstances. Examples are Mediterranean, Santa Fe, New England, and Tuscan.

The architecture in a slum is determined by local conditions and therefore counts as vernacular architecture. Style motives play no role. At the same time, slum architecture is less recognizable than the current known regional vernacular architecture. The way to build in slums seems to be the same everywhere around the world. A high-density urban environment has far fewer variations in landscape, which indeed leads to the regional recognition of vernacular architecture. The universal urban slum environment gives its architecture a globalized nature. The urbanized area is the landscape itself. The global theme of the rapid urbanization is the local condition of which slum is the vernacular architecture. This can be found especially where the pace is very high, as in swelling cities.

Photo 2: Globalised architectural features in both Mumbai...

Photo 3: ...Tokyo, a striking universal element is the blue tarp, which threatens to displace corrugated steel as the icon of the shantytown.

With Glassie’s statement ‘a search for pattern in popular material yields periods’ in mind, a different conclusion can be drawn. Slum occurs in a certain stage of industrial development of a country. The combination of apparent popularity and apparent period would normally reflect an architectural style. Yet that seems not correct. It is not a matter of fashion, philosophies, or imitation of aesthetic motifs. They are local economic and social developments geographical that start slum formation at one time. The global context of the swelling cities leads to uniformity of regional aspects. Despite the apparent resemblance between slums in the world, the architecture is therefore a vernacular architecture.

There have been many studies on economic, sociological, social geographical and anthropological aspects of slums. There are already many plans made by architects for improvements in slums. Experience shows that the scale of improvement plans are of major influence on the ultimate success. Large-scale plans appear more likely to fail than small-scale ones. The piecemeal approach better accommodates the intricate reality of the built environment in which social and economic structures together constitute the urban phenomenon.

Opposite the large amount of studies and policies is the lack of proper documentation of architecture in slums. Accurate knowledge of local building methods may give clues to good development programs. Many ideas on improving the living conditions of slum dwellers are based on replacement building by developers. Regardless of the varying success of such projects, the scale of the slum phenomenon is thus large that it is necessary to address the development potential of slums directly. Slum dwellers themselves are able to build. There are conditions by which development into a fully-fledged town is blocked in such areas. Visualizing this glass ceiling is the subject of many economic, sociological, social geographical and anthropological studies. Good understanding of the potentials that are below the glass ceiling is essential for promoting development.

In addition, knowledge about slums is an interesting source for historians. The development history of cities in the industrialized countries is seen in living form in the swelling cities. The initial symptoms of an urbanizing society reveal the origins of urbanism. The style of building can be seen as the beginning of architecture. The accumulation of techniques gives insight in the profession of engineers.

"The sending of cookbooks to a country suffering famine", is used as a metaphor for the effectiveness of making architectural plans for slums. In that analogy, as it is better to provide food aid that is tailored to the local gastronomy, plans that are based on the local way of building have a much better chance than externally imposed schemes. Knowledge of construction in slum areas is indispensible and it is important that this gap in the architecture library be filled. As one sixth of the world population lives in slums, the architecture section may look forward to a significant expansion of the bookcase.

1. Stewart Brand, How Buildings Learn, what happens after they’re built (Penguin Books USA, 1994) p 132.
2. Henrie Glassie, Pattern in the Material Folk Culture of the Eastern United States (Philadelphia: University of Pennsylvania, 1968) page 33.


  1. great article. very useful

  2. This was just what i was looking for...a straight out look on the topic we normally shy away from. I am currently writing a thesis on how architects can get involve in the menace of slum and this couldn't have been posted at a better time. bravo!