Constriction by Construction

The narrowness of alleys in a slum

A city can suffer of vascular stenosis. Such terms are used when the density of traffic is clogging the roads. One speaks of a traffic infarct when an area is blocked by traffic jams. In this metaphor, the traffic is the blood in the vessels (the streets) of the city. Yet there is something wrong with this comparison. Blood vessels constrict by atherosclerosis, gradually diminishing the blood stream. In the case of the traffic infarct the cause is not a narrowing of the streets but an increase in traffic. It is congestion instead of constriction.

In Dharavi however, the narrowing is actually taking place in the imagery of vascular constriction. We can even speak of constriction by construction. Streets and lanes are narrowing down. A direct cause is the construction of tiny shops in narrow alleys that apparently are not narrow enough yet. The story in the chapter Tailor Made shows how this encroachment works.


Photo 1. An alley, no more than left over space between 'detached' houses.

When Koliwada was still an ordinary fishermen’s village, before it was overwhelmed by the new inhabitants of what is now called Dharavi, the streets had a normal size. Wide enough for two cars to pass each other. Houses were as far apart as enjoyable and necessary. Some intersections of streets were wide enough to form a square. With the population pressure increasing, the pressure to use the open space for building rose dramatically. Squares disappeared. Streets shrank to alleys.


Photo 2. An alley narrower than a normal doorway. Photo 3. Less than shoulder width.

Pedestrians can barely pass each other. It is ‘Hold your belly’ or wait until there is no oncoming traffic. An overview is hard to get in the network of alleyways and passages. An open space is an important marker and many routes through the maze can only be overseen by remembering which space is connected to another open space through which alley. The trouble is of course that it is a natural temptation to fill a large open space with building. To get an impression of the original width of streets and squares, it helps to distinguish the age of buildings. Doing so we see what was already there and what was built later. Insight is improved by recognizing that order. By imagining the moment a particular building did not yet exist, we get an impression of what were once the normal dimensions of public space. In the following three pictures, the big pink house in the background is what was already there.


Photo 4. Three photos of one building. With this kind of infill, open spaces disappear leaving a network of alleys only.

Clearly the gray house in the foreground was added later. It is hardly two meters wide and maybe four meters deep. The front door is covered with a blue curtain with red and yellow flowers. The stairs to the room above it are on the outside. Perhaps the upper chamber is a separate dwelling. The lacquered wooden door with the blue frame is the original door of the big pink house. The green door on the first floor is also part of the big pink house. The stairs serve both the top floor of the old house and the upper chamber of the newer house. Thinking about the order of building it could well be that the ladder was already there before the new house was built, as the first floor of the pink house had to be accessible anyway. Considering the big pink house only, the first floor is probably also added in a second stage. Therefore the stairs are outside, next to the door. It is no use to build steps right in your living room and not in front of the door either. And so on. Thus the time factor makes the logic behind this seemingly irrational compositions transparent. To get the picture of the original wider streets, just imagine that last built grayish house not being there. This once was a village with very normal streets.

A less obvious reason for the narrowing of the streets is the adding of floors on top of existing houses. Stairs play the leading role in this. The upper floor needs access of course and therefore steps are necessary. Designing a staircase is a puzzle in itself, as described in the chapter Ladder.


Photo 5. Sophisticated staircase, wrapped around the corner of the groundfloor dwelling.


Photo 6. The house on the right is extended over the alley. The columns and overhang form an arcade.

The roof is a convenient place to expand a house. Land costs do not apply and the floor is already there. Only four walls and a roof are needed, and steps to get upstairs. There are two options for the location of the stairs. Inside the existing house or outside. Stairs inside come with a few objections. A staircase takes space while the intention was to gain additional space. Also a stairwell should be made in the existing roof, which requires many additional structures. With the cutting out of the stairwell, space is lost on the floor upstairs. An internal staircase is expensive and causes a loss of space on both floors. A staircase on the outside doesn’t have such drawbacks. The existing house remains untouched. And a big advantage is the independence of the new floor. It has the potential to be rented or sold as a private entrance available. An outside staircase is thus a very sensible choice.
Therefore, with the addition of a floor usually comes a staircase outside the house.


Photo 7. Steps halve the passageway. Photo 8. The alley gradually becomes a tunnel.

These stairs, of course still requires space but in this solution it is at the expense of public space and not of their own space. The increasing number of stairs reduces the capacity of the alleys. In some situations, placing stairs is virtually impossible. And although it may sometimes look messy, the ingenuity of the builders deserves appreciation.

Photo 9. The (left) ladder’s the lower half is narrower, in favor of the traffic space in the alley.

Photo 10. The passage on the street remains usable by clever use of a platform top.


Photo 11.The elevated ground floor (convenient in case of flooding) is used as an impetus for the stairs.



Photo 12. Two photos showing two directions in one alley. The neat pavement and the overhanging first floors turn the space into a room on its own.

The additional floor on the house is often built as a cantilever. The new floor sticks out over the alley. This provides additional space on the first floor and creates a kind of ceiling in the alley. Besides the benefits to the alley, like shelter from sun and rain, there are disadvantages as well to the quality of the houses. In their growth upwards, the houses also grow closer to each other which is detrimental to the entry of light and air. Also privacy suffers considerably. Besides clean water and sanitation, privacy is a scarce article.