CHICAGO—Luxury rental buildings have become some of the hottest properties in the nation's urban cores, but many of the millennials that could make up a good portion of the renters may feel priced out of this housing. Some operators have gotten creative, and decided to encourage young renters to share apartments by signing leases for individual bedrooms, rather than for whole units, and continue the co-living arrangements they probably had during college.

“We believe that they have already accepted that model as students, and this has helped us stabilize properties faster,” JJ Smith, chief operating officer at CA Ventures, tells GlobeSt.com. “While co-living is a newer strategy for market-rate communities, it's a model we've been using for more than a decade in our off-campus student housing developments.”

Across the Chicago-based firm's portfolio, the share of non-student residents in co-living residences has doubled from less than 2% a few years ago, to 5% today. And non-student residents, including transient corporate workers in search of furnished housing, make up as much as 15% of the tenant mix at the company's co-living properties in urban centers.