More people — many of them Millennials — are moving into downtowns, and density is increasing.

But others are leaving the concept of traditional suburban life behind for something that isn’t in the middle of the city, but does feature very close neighbors and communities. They’re categorized as co-housing areas, which involve private spaces with shared facilities.

For a couple of perspectives, we spoke with Brian Stark, who lives with his family in the Milagro Cohousing community in Tucson, and Bella DePaulo, a social psychologist at the University of California-Santa Barbara. She’s the author of "How We Live Now: Redefining Home and Family in the 21st Century."