The Nubian vault is an African technique for the construction of timberless vaulted roofs. The AVN (Association la Voute Nubienne), through its Program ’Earth roofs in the Sahel’, helps provide families in sub-Saharan Africa with comfortable, sustainable, affordable, homes.
In a recent Newsletter from this organization, I was impressed by the statistics they provided regarding the impacts of their program:
Since the start of the program, 1309 vaults have been built by Nubian vault masons and entrepreneurs, for 533 clients, in 244 locations (villages, hamlets, towns) in 5 countries (Burkina Faso, Mali, Senegal, Zambia, and Madagascar). If all the vaults built were to be placed end-to-end, this would reach a total length of 9.7 km.
In total, 214 masons have been trained, of whom half are at the foreman and/or entrepreneur level ; and there are currently 296 apprentices in training.
10,000 people use, live in, or sleep in Nubian Vault buildings; of the total built, 85% are for private houses, and 15% are community-use buildings.
Approximately 18,000 trees, 25,000 tonnes of CO2-equivalent, and approximately 15,000 corrugated iron roofing sheets have been saved as a result of NV construction, as compared to the alternatives.
Approximately 750,000 Euros of local economic impacts have been generated by the program.
Since 2000 the program has experienced an average annual growth rate of 36%.
We at www.earthbagbuilding.com have been cautious about recommending the construction of vaulted roofs using earthbags because of issues with stability. Using small and solid brick units for construction does make this sort of vault possible. I would still be cautious in suggesting that people follow the lead of Nubian Vault construction in climates where there is any danger of moisture soaking into the mud bricks and causing the vaulted roof to fail. But in sub-Saharan Africa this is obviously a very viable alternative to other roof systems. In wetter climates, the use of fired or otherwise stabilized bricks is also possible.