The concave roof was designed for arid environments, where rainwater harvesting can be difficult due to high evaporation rates and low annual rainfall. This flysheet system, which includes a domed roof below a bowl-shaped catchment area, is designed to help collect even the smallest amounts of rain, which melt into larger droplets - just enough for collection earlier. it evaporates.
In addition, a concave roof on top of a convex roof favors natural cooling through the movement of shadow and wind between the two roofs.
The bowl-shaped catchment area is sloped enough to bring the raindrops to a central point, where the rain is funneled into a storage system. Spaces between the walls are used to house the storage system, in a way that helps regulate the internal temperature of the building.