On the night of February 27th, 2010, Luis Enriquez had just gotten home from his job at a lumber factory in Constitución, Chile. At around three o’clock in the morning, Luis started to feel the earth shake. It was an earthquake—a bad one.

With a magnitude of 8.8, the quake that hit Constitución was the second biggest that the world had seen in half a century. The quake and the tsunami it produced completely crushed the town. By the time it was over, more than 500 people were dead, and about 80% of the Constitución’s buildings were ruined.

As part of the relief effort, an architecture firm called Elemental was hired to create a master plan for the city, which included new housing for people displaced in the disaster. But the structures that Elemental delivered were a radical and controversial approach toward housing.

They gave people half of a house.

The houses are simple, two-story homes, each with wall that runs down the middle, splitting the house in two. One side of the house is ready to be moved into. The other side is just a frame around empty space, waiting to be built out by the occupant.

Elemental has made a name for itself building these half-a-homes, and not just as disaster relief. The response from the architectural community has been overwhelmingly positive. In 2016, the firm’s founder, Alejandro Aravena, was awarded the Pritzker Prize, one of the top prizes in the field.

These half-built houses are a unique response from urban planners to the housing deficit in cities around the world. The approach has its roots in a building methodology made popular by the 1972 essay, “Housing as a Verb,” by architect John F.C. Turner. Turner made the case that housing ought not be a static unit that is packaged and handed over to people. Rather, housing should be conceived of as an ongoing project wherein residents are co-creators.

Turner and other advocates of this approach, called “sites and services,” began doing building projects where they would work with governments (and/or private partners) to build the parts of housing that residents have the hardest time building on their own—things like concrete foundations, plumbing, and electrical wiring. Governments would also provide services—such as roads, drainage sewers, garbage collection, and schools—to the site.

Over time, residents would turn the component parts of their basic sites into suitable housing, on their own terms. They donate their labor and pay the cost of materials to finish the house. In the end, they own what they build.

In 2002, Elemental received a commission to build 100 units of low-income housing in the city of Iquique, Chile. Their budget was $7,500 per unit. The community was adamant that they did not want large high-rise style public-housing, and even threatened a hunger strike that type of housing was provided.

So, Elemental chose to build half-houses—tall rectangular units separated by empty space. Each one was just big enough to meet Chile’s minimum standards for low-income housing. Then residents on their own time would expand into the adjacent empty space.

Elemental spent the next few years iterating on this concept, and then in 2012, after the earthquake in Constitución, they received a commission to help create a masterplan for the city, which included creating a new neighborhood full of these incremental buildings.

Located on a high hill above the town, Ville Verde is made up of neat rows of houses, with half of each house identical, and the other half completely different. When people got their house, much was unfinished. The drywall was unpainted, the floors unfinished. Kitchens came with just a sink—no refrigerator, stove or cabinets.

Villa Verde resident Luis Enriquez worked first on making his house bigger. With help from his wife and brother—plus workshops and manuals provided by Elemental—Luis laid concrete on the empty side of the house and put up exterior walls, and flooring for the second story. His house was now big enough to comfortably accommodate his family.

Would such an approach work in the United States? Jennifer Stoloff, an expert in evaluating government housing programs sees an alignment with the American ethos of “pulling yourself up by your bootstraps” but also many risks, including litigation issues related to safety.

The biggest hurdle to an incremental building project working in the U.S. isn’t a matter of safety or legality, however. Stoloff believes the U.S. would view it as “an embarrassment.” Even though we might end up providing more people with adequate housing, “we couldn’t do it—we’d lose face,” says Stoloff.

In Chile, these projects have grown out of a culture of scarcity. But even with more money, the builders at Elemental believe that their approach would not change. With a bigger budget, they’d choose to spend money the public space surrounding the neighborhood. And this is at the heart of the sites and services approach—improving the community, and letting home owners invest in and improve on their homes.