I was recently contacted by Antoine Horellou and made aware of Association la Voûte Nubienne (AVN). The following is an introduction to the technique and the organization based on information provided on AVN’s website (which is also available in French). Thanks, Antoine, for letting us know.
The Nubian Vault is “an affordable, sustainable, African building technique.” It uses mud bricks and earth mortar, assembling them into arched, vaulted ceilings without the need for timber. Water- and weatherproofing is incorporated into design with plastic sheeting and an additional layer of enriched mud mortar covering the roof and optional additional concrete, lime or tar finishes, depending on need based on local conditions.
Designs can use simple standard vaults or use reinforced concrete pillars and beams to open up larger spaces. Doors, windows, interior finishings and accommodation for electrical wiring and plumbing can all be incorporated. In more advanced applications, the vault technique can also be incorporated as one of many elements in more sophisticated architectural designs.
The technique originated in upper Egypt and vaults of unfired earth bricks at the Ramesseum—the funerary temple of Rameses II in Luxor—are still standing 3,250 years later. The NV technique is virtually unknown elsewhere in Africa but over the last twelve years, Association la Voûte Nubienne (AVN) has been working to successfully introduce a simplified, standardised version of this ancient technique in Burkina Faso, Mali, Senegal, and Zambia in what they call “a good example of ‘South to South’ technology transfer.”
See how a nubian vault is built. Here, a man uses sun-dried earth bricks and earth mortar, keeping the arc constant with a guiding line:
AVN was founded in 2000 by Thomas Granier, a French builder, and Séri Youlou, a Burkinabé farmer. Its mission: “decent housing, as soon as possible, for as many people as possible.”
The group sees the building practice as a solution to housing issues caused by expensive and scarce materials in many parts of Africa. Operating as a social enterprise (a for-profit business driven by a social mission), AVN focuses on three key elements—”a roof, a skill, a market”—building structures, training builders and raising awareness of the technique, creating more demand.
As Horellou says, “We diffuse in Africa the ancient nubian vault technique, redesigned and adapted to the base of the pyramid in the African Sahel region. We support local entrepreneurs (200 to date) that provide this technique to the BoP (already 1500 nubian vaults built with a 36% annual growth rate) and train new apprentices.”
“In semi-arid regions of Africa, bush timber has been used for roofing and for load-bearing supports. However, climate change, deforestation, and increasing population growth mean that traditional building techniques are no longer feasible.
“People in rural areas have to buy sheet metal (corrugated iron), sawn timber beams and rafters for roof-building. These imported building materials, with their deplorable thermal, acoustic, and aesthetic properties, must be paid for in cash, a problem for those living mostly outside any formal economic system. Finding the necessary funds becomes a major drain on family resources and on local economies.”
“Teams of African masons trained in the Nubian Vault (NV) technique who build safe, sturdy, well-insulated vaulted roofs of mud bricks and train local apprentices on-site. The bricks are made from locally available earth and water, dried in the sun, and can be protected from rain erosion by traditional methods. Houses with Nubian Vault roofs cost less to build than those with tin and timber roofs, are cool in hot weather, warm in the coldest of nights, and can last for 50 years or more if properly maintained (as opposed to the average 7–10 year lifetime of a tin roof).
“Association La Voute Nubienne (AVN) promotes the development of a self-sustaining market in NV construction, by facilitating the recruitment, on-site training, and support of village masons in several African countries (Burkina Faso, Mali, Senegal, Zambia). AVN’s local teams and extension agents pump-prime and enable the growth of indigenous markets in Nubian Vault construction, providing employment opportunities, access to decent housing, and the growth of local economic circuits.”
Statistics to date:
“Since the year 2000, AVN has seen an annual growth rate of 36% in the numbers of masons trained and vaults built. By 2011, in Burkina Faso, Mali, Senegal, and Zambia:
- Over 200 VN masons have been trained
- Over 1,300 vaults built, for some 800 buildings
- Carbon savings of ~ 2,600 tons of CO2-equivalent achieved, compared to alternative construction methods
- 10,000 people (client families, masons, apprentices, laborers…) have benefitted directly from NV buildings
- Over € 500,000 of economic impact on local economies have been achieved
AVN’s work has achieved major international recognition by SEED in 2011, the World Habitat Awards in 2009, the World Bank Development Marketplace Competition in 2009, the Tech Awards in 2007 and Ashoka’s Changemakers Prize for Affordable Housing 2006, among other awards. On March 16, AVN announced that they have “taken on the Buckminster Fuller Challenge, and we are in the running for a $100,000 prize for our Earth Roofs in the Sahel program.”
For more information on Association la Voûte Nubienne and the nubian vault technique, including specifications and more great examples of their work, visit AVN’s website. They can also be found on Facebook and Twitter (@EarthRoofs).
Photo credits: Association la Voûte Nubienne