The design team at WASP (World's Advanced Saving Project) will unveil what is being billed as the world's largest 3D printer on Friday in Rieti, Italy. Dubbed the "Big Delta," this enormous device stands roughly 40 feet tall with a 20 foot diameter. But despite its size, the Big Delta is extremely efficient and uses only 100 watts of power. Its oversized design allows the Big Delta to quickly and easily print low-cost disaster-relief housing. What's more, it can do so using locally-sourced materials (read: dirt and mud) which also acts to minimize construction costs. The WASP team also foresees employing this printer for non-disaster-related home building. According to a company release, the Big Delta help accommodate the estimated 4 billion people worldwide that will lack adequate housing by 2030.