Tabula non rasa

Slum is an accumulation of improvements

Building often begins with demolition. A building that does not meet requirements any longer must make room for something new. It is often no use to build on what already was, and the purpose of scrapping is to begin with a clean slate, the tabula rasa. Demolition makes working a lot easier for designers and builders. Designers do not need to study the current situation and do not loose time puzzling on new features in old spaces. It is easier for builders. Tinkering with existing work is very labour intensive and full of uncertainties. It is unclear how sturdy the existing work is and how it is fit together. Many builders prefer to start something new.

The building being demolished was once established through various design choices. The choices made in the past are reversed with the demolition. Demolition is actually a step back in time, a step into the situation prior to the demolished building. With this step back in time history is lost. The new building says nothing about the history of building on that spot. The building history is at best found in a memory.

In a slum, one can often not afford the luxury of demolition. Building a larger home usually means extending an existing house by a floor on top. Choices from the past remain visible and set implications for further development. Continued building means puzzling with the existing situation. The current situation imposes restrictions on the new design. It requires much creativity and inventiveness to get all connections, both spatially and technically, of old and new quite right. Design issues and building projects are therefore in a slum more complex than average. As a result, especially proven techniques are used. Style architecture makes little chance. Avoiding risk is crucial, because of financial constraints. In his book How Buildings Learn1, Stewart Brand shows how not only the initial design determines the shape of a building, but also how the subsequent existence leads to growth and change. In a slum, especially that growth and change are built, not style and originality. “High-style architecture likes to solve old problems in new ways, which is a formula for disaster, according to Dell Upton at the University of California. Vernacular builders, he says, are content to accept well-proven old solutions to old problems. Then they can concentrate all their design ingenuity strictly on new problems, if any. When the standard local roof design works pretty well, and materials and skills are readily available for later repair, why would you mess with that?”2 This risk-evading manner is a basic principle in building slums.

What makes Dharavi so fascinating is the ability to read the entire history of construction on the existing buildings. All the creativity that was necessary to achieve something good under difficult circumstances and all imagination that facilitated further development is visible to those who have an eye for it. Stewart Brand also observes that: "There is a magazine called Progressive Architecture but none called Conservative Architecture. If there were such a magazine (...), it would be largely about vernacular architecture, which is profoundly cautious and imitative, so immersed in its culture and its region that it looks interesting only to outsiders.”3 The architecture of Dharavi and other slums meets exactly this description. Indeed, not only the appearance is cautious and conservative, the physical reality is too. Demolition is a rare activity.

Although an architect will never design a slum, the architecture of a slum is an essential source for designers.

1. Stewart Brand, How Buildings Learn, what happens after they’re built (Penguin Books USA, 1994).
2. Quote in ibidem, p 132.
3. Ibidem, p 132.