We built this structure on our farm in the Fall of 2012, with help from Massey Burke and Stevan de la Rosa. Nubian vaults have been built in the deserts of Southern Egypt for at least 7,000 years. Their catenary geometry puts all the forces in the building into compression. No formwork is used, enabling a space to be enclosed with no wood except the tiny amount necessary for block forms. Because we are in a seismic zone, we reinforced the vault with split bamboo after it was built. The grey exterior plaster was made entirely from local ingredients: clay, sand and cattail fiber all sourced from our creek. Many thanks to Stevan and Massey, and also to our wonderful interns, especially Beck!