Designs that appeal to young renters tend to break the rules. Specifically, these designs don’t compartmentalize life’s various functions the way traditional floor plans once did. “The lines are blurred between work and life,” says Primo Orpilla, principal for San Francisco–based Studio O+A Interior Design.

In response, designers like Orpilla are creating spaces that obscure the boundaries between inside and outside, bedroom and living room—even past and present—all in hopes of pleasing Gen Y renters.

This new design aesthetic seems to be an interesting mix of the very new and the very old. Think of a shiny new iPhone in the pocket of a “distressed” pair of jeans.

At 1880 Mission, a 202-unit rental community developed by Avant Housing in San Francisco, for example, Studio O + A’s sleekly modern design incorporates brick and timber salvaged from the original 105-year-old building on the site. “We pulled as much archival stuff from the [old] building that we could repurpose or reuse,” says Orpilla, whose firm also designed the new Facebook headquarters in Palo Alto, Calif.

Inside the apartment complex, which is scheduled for completion later this year, more recycled wood appears in the restaurant-quality kitchens. The historic references even creep into the marketing materials, also created by O + A, which include signage and graphics from an old print shop once located on the site.

“This generation does think about the stories of previous occupants,” says Orpilla.

In communities like Avant’s 1880 Mission, common areas blur the boundaries between work and play and public and private spaces with small, comfortable spots where residents can perch, open their laptops, and take advantage of wireless high-speed Internet access. They can also potentially enjoy chance meetings with their neighbors. All are modes of connection craved by the Gen Y renter the community targets.

“They want nooks and crannies,” says Orpilla. “You want to live in the space. You want to feel comfortable in the hallways.”

Of course, the developer also includes larger community amenities it can brag about in its marketing materials, from bike rooms to fitness centers to an “exhibition-style kitchen where residents can play,” Orpilla says.