Although there is no limit to the length of a VN vault, its width cannot exceed 3.25 metres. As some buildings (e.g. classrooms, churches, community centres...) need to be much wider internally, we have developed a technique combining VN vaults with reinforced concrete beams and pillars (VN+RC) to support the vaults.

The Association Africabougou (Italy) and its President, Emilio Caravatti in Mali, and the architect Chiara Rigotti from the Association Arquitectos Sin Fronteras (Spain) in Burkina Faso, in collaboration with the AVN and VN builders, have designed and built the first prototypes of this new concept.

The combination of VN vaulted roofs with reinforced concrete pillars and beams (VN+RC) not only provides much wider open spaces (7 to > 10 metres), but also has other advantages:

 a saving of 25% in overall costs compared to comparable metal roofed buildings
 a significant involvement of the local population (= eventual users) towards construction costs, in the form of unskilled labour
 a re-injection of building costs into the local economy (labour) and a reduction in the purchase of imported materials
 enhanced sustainability and comfort of the buildings.

A comparative cost study is currently being undertaken of the VN+RC model, based on the early prototypes. The results will be published on this site.