Petaluma Avenue Homes, an affordable cohousing community in Sebastopol, Calif. (Photo by Schemata Workshop.)

Back in the good old days, I’m told, people lived in neighborhoods where they looked out for each other. They had potlucks, kept an eye on each other’s kids, loaned out lawnmowers and cups of sugar. Each home was its family’s castle, but the instinct to participate in a caring community transcended the temptation to isolate in private houses.

Apparently we’ve strayed so far from that norm over the last half-century or so that it now takes a conscious effort to recreate it. That’s one way to view cohousing, a collaborative housing model imported to the United States from Denmark in the 1970s, in which “residents actively participate in the design and operation of their own neighborhoods.” In the approximately 125 cohousing communities in the U.S., residents share chores and responsibilities, come together for meals and other activities in a common house, and make decisions based on consensus. It’s a conscious way of living designed to encourage social interaction and investment in the greater good.