For a long time, the suggestion of couples (at least couples under 70) sleeping in separate rooms was something of a taboo: It signaled a giving up—on romance, on sex, on the pretense of togetherness. Sleeping apart was a death knell for a marriage, or at least a runway into the nursing home.

Now, though, it’s an of-the-moment design feature, as more and more couples—and more and more younger couples—seek out separate bedrooms (and the separate closets and bathrooms that go with). “It’s gone beyond just wanting separate his ‘n’ hers closets,” says Ralph Choeff, principal of Miami firm Choeff Levy Fischman, who’s currently at work on dual masters for a young Miami couple. Though they get those, too: “The last estate I designed had two master suites,” says L.A. interior designer Lori Halprin. “The gentleman incorporated his bedroom with his home office. The woman was a clotheshorse and wanted the extra sitting area made into a closet.”

I can’t say I don’t buy in: I spend many nights lying awake thinking my husband is great and all, but couldn’t he just breathe a little less? “It is about practicality,” says New York City agent Greg Moers of Triplemint. Moers points out that one reason master bedrooms are multiplying is that more homeowners, at least in Manhattan, are converting two (or more) adjoining apartments into one. But he’s also seeing far more units created with two masters from the get-go. “I think it’s because of how different everyone’s schedule is these days” he says. “One’s in finance, the other is in publishing. Our careers are so important and it takes a lot out of us to do it at a high level. We need our sleep.”

Elissa Morgante, co-principal of Morgante Wilson Architects, which specializes in high-end residences on Chicago’s North Shore, recently worked with a couple who requested dual master suites as part of a renovation of their home on Lake Michigan. They’d slept in separate rooms (of different sizes) for some time—he’s a “morning person”; she prefers total darkness. Now, though, they wanted a more elegant, equal-opportunity setup. Morgante created a new master wing in which a shared hallway joins his-and-her bedrooms, each with its own door. Fittingly, the husband’s is east-facing, with views of Lake Michigan; the wife’s overlooks the west, with windows outfitted with blackout curtains. Each got to satisfy his or her own design preferences: She chose peach salmon, while he accented with Roman shades in a nubby linen. The couple comes together in a shared master bath.

“Just as technology evolves, so do people,” says Choeff. “I would say it’s an evolution of not only sleeping habits but bathroom habits, work schedules, and simply personal space that most of our clients frankly can afford.”

And agents say dual masters make for a surprisingly easy resell—once people get over what they think an excitement over two masters may say about them (or their sex life). “I do get some buyers who need the dual master layout explained and are taken aback,” says L.A. agent Robert Sandefer, currently selling dual masters at 861 Mandalay Beach Road in Oxnard. “Some insist there can only be one master. But once the benefits are explained, they’re often pretty easily convinced.”