Detroit is undergoing a remarkable process of un-building, its residents literally transforming its denser neighborhoods into sparse suburbs. It’s the inevitable consequence of the shrinking of a once-great city.

By estimates of the city and various experts, about 40 square miles of the city’s 139 square miles are vacant today — empty fields from which all structures have been removed.

We’ve seen other suggestions for large-scale solutions to Detroit’s loss of population, including a re-wilding carried out by bulldozers and bison and covering all that open space with solar panels. But the fencing-the-neighbor’s abandoned-lot solution has the advantage of being grassroots. It works in part because residents aren’t waiting for the city to sanction their actions.

In some of the emptier parts of Detroit, homeowners in recent years have fenced in the vacant lots next to their houses to create suburban-size parcels for themselves. Sometimes relatives or friends whose houses are separated by two or three lots will fence in all of them to create their own private compounds.

So far, these efforts at reclaiming lots account for only 5 percent of the city’s vacant land. The rest will have to wait for the only half-man, half-machine who can save the motor city: Robocop. Fortunately, he’s on his way.