Djenné and Sustainability

When analysing mud building, the fact that the construction footprint (including transport of materials) is little bigger than the footprint of the site itself is surely the pinnacle of sustainable construction. In Djenné the buildings are predominantly flat roofed, wooden beams spanning the mud walls, covered with mud. With the source of wood being the slow growing palm trees indigenous to the area, this system brings the sustainability aspect into question. In the case of the mosque, which is currently undergoing restoration, I think 100 years of use more than matches up to the growing rate of the palms. But as far as the town as a whole is concerned there is the issue of erosion in the desert due to the removal of trees that will need to be addressed, especially given the town’s delicate relationship with the Niger. It will be interesting to see how the traditional building techniques of the town’s people evolve to answer this problem. I’ve heard various suggested solutions including the Nubian vault, as coined and revived by Hassan Fathy, constructed without the need of timber framework and utilising the adobe bricks already in use, which are of course plentiful. But what are the consequences of introducing an outside technique? Does this in some way dilute the vernacular purity? Whatever happens a tree-planting project is due, I wonder if the Aga Khan Trust have plans to implement such a precaution. If so I think maintaining it could be the greater challenge.

An ancient technique, the Nubian Vault is constructed in layers of mud bricks without the need of wooden framework (conventional arches and vaults are normally supported by a timber frame until the keystone is set in place at the apex). Building horizontally off a vertical wall each layer of brick is angled and so supported by the previous layer.

Nubian Vaults under construction.