The 15-Minute City—No Cars Required—Is Urban Planning’s New Utopia

The Minimes barracks in Paris don’t look like the future of cities. A staid brick-and-limestone complex established in 1925 along a backstreet in the Marais district, it’s the sort of structure you pass without a second glance in a place as photogenic as Paris.

A closer look at its courtyard, however, reveals a striking transformation. The barracks’ former parking lot has become a public garden planted with saplings. The surrounding buildings have been converted to 70 unusually attractive public housing apartments, at a cost of €12.3 million ($14.5 million). Elsewhere...