By 2030, five billion people will reside in cities; 40 percent of them will live below the poverty line. As part of the Pritzker Prize ceremony at the United Nations headquarters this April, 2016 Laureate Alejandro Aravena addressed the projected housing crisis that will occur in less than 15 years."Every week, we would have to build one new city for a population of one million people, with $10,000 per family," the Chilean architect said. "And if we don’t solve this equation, it is not that people will stop coming to cities—they are going to keep coming—but they will live in awful conditions."Aravena offers a solution that allows people to take matters into their own hands: a series of open-source blueprints that are now available to the public on the website of his Santiago-based firm, Elemental. The four designs are all examples of Aravena’s inexpensive-to-build "incremental housing" projects, partially completed structures that residents can develop and customize over time. As he said in a prelude to the 2016 Venice Architecture Biennale, of which he is the chief curator: "We believe that the advancement of architecture is not a goal in itself but a way to improve people’s quality of life."