BOGOTA: Dozens of families living in El Salvador’s slums hope to swap their makeshift wooden shacks for concrete 3D-printed houses next year, in what developers say is the first project of its kind in the world. ICON, a Texas-based construction technology company has unveiled a 350 square foot (33 square meter) house, which it printed and built in two days using a gigantic, portable 3D-printer. “Something that sounds like science fiction is real,” Jason Ballard, ICON’s co-founder, told the Thomson Reuters Foundation. “We plan on printing a whole sort of development ... not just a 3D-print house but a 3D-printed neighborhood.” Globally nearly 1 billion people live in slums, often in shacks made from scraps of metal and wood with dirt floors, according to the UN, which predicts the world’s population will reach 8 billion by 2030. Innovators are racing to develop quick, cheap technology to address global housing needs. Dubai opened in 2016 what it said was the world’s first functioning 3D-printed office building. Ballard said ICON’s house is the first to be built on site and receive a permit — from the UScity of Austin — allowing someone to live in it. “We had to build it to the highest international standards of building safety,” he said. New Story, which builds homes in developing countries, has partnered with ICON and they plan to transport an updated version of the 3D-printer to El Salvador and produce 600 to 800 square foot versions of the house in 24 hours. They plan to build about 100 homes for people in slums in the Central American nation within 18 months, while reducing building costs to about $4,000 from $10,000. “It represents the chance for breakthrough technology to come to developing areas first,” said Alexandria Lafci, co-founder of San Francisco-based New Story. “Having a safe home is truly a foundation.” Living in a hazardous shack or tent is dangerous for people’s health and wellbeing, making it difficult to perform well at school or work, she said. A mix of concrete, water and other materials are pumped through the 3D-printer, which then pours out a hybrid of concrete mortar that hardens as it is printed, producing layers of structures used to build a house. “The material has to be have some pretty unique features. It has to flow out ... but it can’t flow like water as you would just have a puddle of concrete and so it has to set pretty quickly,” Ballard said. “This is meant to be long-term sustainable housing. Concrete is one of the most well understood materials on earth and it’s also one of the most resilient.” Two possible sites where the 3D-printed homes could be built on have been identified, one outside the capital San Salvador and another about two hours away from the city, Lafci said. Local authorities will grant the land on which the homes will be built on to the slum-dwellers, she said. Families taking part in the project will pay a small, interest-free mortgage, which should take between five and 12 years to clear, she said. “When they pay off their mortgage, they own both the home and the land that the house sits on,” Lafci said. “Land ownership can be a stride to getting out of poverty.”