Dharavi in Mumbai houses one of the largest slums in India. Founded in 1882 during the British colonial era, Dharavi slum spreads over an area of 217 hectares and is home to almost a million people. The slum grew in part because of an expulsion of factories and residents from the peninsular city centre by the colonial government, and from rural poor migrating into urban Mumbai. There have been many plans since 1997 to redevelop Dharavi on the lines of former slums of Tai Hang in Hong Kong.
CRG Architects and Consultants have proposed a very unique housing solution for the dwellers of the densely populated Dharavi – the Containscraper, using standard shipping containers. The irregular-shaped site offers them design freedom, and allows them to push up the height of the tallest tower to maximise volume.
After thoroughly investigating the site conditions, they have located two towers with a maximum height of 400 metres for the tallest tower and 200 metres for the smaller one. A cylindrical base for the towers maximises direction of views. The site’s characteristics and the proposed street alignments helped with the geometry optimisation of the design. The position of both towers, as a response to the irregular shape of the site, gives an opportunity to this area to be the new landmark of the city with a new visual presence.
The architects share the design intent, “The classical and standard container’s storage position allows us to have only one direction of views, and the gap for opening windows is made from the smallest side. Rotating by 90 degrees the position of the containers, we get more façade surface and greater possibilities for opening windows, but still only one direction of views. Changing the position of the containers following a cylinder shape, we obtain multiple views around the site. Alternating them around the cylinder, we make the wind flow through the containers, helping them remove and decrease the amount of heat.”
Shipping containers offer themselves as the modular building element, as they are of the same width (8 feet) and two lengths (20 feet and 40 feet) across the world. This facilitates easy interlocking, stacking during construction and transportation. The shipping containers are supported by the vast transport infrastructure – sea, rail and road. Due to their structural strength and resistance to heavy lateral loads like ocean water forces, corrosion, mold, termites and fire, they can be readily used to carry heavy loads.
They are very effective building elements and helpful in structural stacking to create storeys, while being cost effective as compared to masonry, which is much more labour intensive.
The circular footprint of the tower allows to adopt the old fortification method for self defence that offers a much needed sense of security to its inhabitants. Some shipping containers have been placed in vertical orientation to form the core of each tower, and offer themselves for placement of elevator units. Some containers are used as water tanks and knitted within the vocabulary of the design.
Each dwelling will have its own water reuse system integrated with a central system facilitating treatment and reuse of grey water and black water. This will help solve very critical issues related to sanitation and public health in Dharavi, which has been very severe often resulting in epidemics and disease.
Though it may appear random, the shipping containers follow a uniquely programmed mathematical pattern to allow maximum flexibility. Vertical gardens along with gaps in the placement of the containers will significantly reduce the heat transfer and help to combat intense summers of Mumbai, while increasing natural ventilation in each unit.
The original colours of the containers have been very creatively used to create a very interesting façade vocabulary that responds to the heating rate of each side of the building and the solar incidence of the site. The warm colours on the south side transition through tonal changes in the east and the west into the cooler colours on the north side. The Containscraper can provide housing for 1,300 families in Dharavi.
(The author, an architect and educator, can be reached at Vani.Bahl@gmail.com)