Working in collaboration with developer Buřinka (aka Stavebni Sporitelna Ceske Sporitelny), sculptor Michal Trpák has designed a 43-square-meter concrete house called Prvok—a structure that can be 3D-printed in just 48 hours and will float on water. The first of its kind in the Czech Republic, the house’s building process not only cuts construction costs, reduces CO2 emissions by 20% and minimizes waste, but the resulting structure also has various eco-friendly elements built in. There’s a green roof, reservoirs to collect water, a recirculating shower and more. While small in size (with a living room, kitchen, bathroom, and bedroom), it’s a big step toward alternative housing solutions—and fast ones, considering this can be produced seven times faster than traditional housing. Read more at designboom.