Made from 20-foot-square intersecting concrete vaults, the structure takes inspiration from cloister architecture and the canopies of trees in the area.

Materials researchers from ETH Zurich has revealed a prototype for an ultra-thin, sinuous concrete roof system with an average thickness of just 5 centimeters.

Being carbon neutral requires more than just special concrete and eco-friendly paint, of course. The Hi’ilani EcoHouse’s wing-shaped structure cleverly hides powerful solar arrays.