Back in 2014, we were excited about the giant 3D printer USC Professor Behrokh Khoshnevis had designed with funding from NASA and the Cal-Earth Institute. The robot was able to build a 2,500-square-foot home in just 24 hours. The process was then known as Contour Crafting and was barely in the research stage. Fast forward to today, the big machine has progressed and seems to have the power to aid the pressing homelessness issue. Currently, the world lacks homes for more than one billion people, according to a report by the World Resources Institute Ross Center for Sustainable Cities. Some areas are in more distress than others, such as El Salvador, where to build a house it tricky because of the land’s vulnerability to earthquakes, flooding and volcanic eruptions. Yet, San Francisco-based housing charity New Story built more than 850 homes in El Salvador, Mexico and Bolivia in the past several years. Those homes costed $6,500 each and each of them took more than two weeks to build. The slow process spurred the company to search for better ways to build. That’s how they came in contact with ICON, an Austin-based construction tech company, to create a 3D printer that can build a 600 to 800-square-foot house in 12 to 24 hours for as little as $4,000. This printer, called Vulcan, was unveiled at SXSW along with a 3D printed house, built to U.S. standards, that’s in an Austin, Texas backyard. The model in Austin has a bedroom, living room, bathroom and a curved porch and the ‘ink’ used in its development is in fact cement, which the company claims, will help normalize the process for potential tenants that wish to know more about the sturdiness of the structure. The machine is designed to...