The winner of this year's eVolo Skyscraper Competition was a foldable skyscraper concept named, Designed by Damian Granosik, Jakub Kulisa, and Piotr Pa?czyk, the project can be delivered by a helicopter. The flattened structure is designed to be packed into a box only as wide as the building's base, so it can be suspended under military helicopters.  The base would be anchored in place and a "load-bearing helium balloon" would be inserted so that the external and internal walls would unfurl rapidly as the balloon rises. Lightweight 3D-printed slabs forming each floor would be pulled upwards by structural steel wires attached to the balloon. These wires would be strong enough to resist wind once the temporary skyscraper was in place. The team also proposed using a nano-material based on ETFE foil embedded will tiny solar panels so the tower can produce its own clean energy in case of emergency power cuts. The balloon at the top of the structure would have a hollow center to collect and filter rainwater.