CHICAGO—The lucrative sales of class A multifamily properties, especially ones in the city, typically generate headlines, but underneath the radar many investors have developed an appetite for older suburban product, and the Kiser Group felt it was time to publish some research on the topic. The Chicago-based firm just produced a sales data report, the first of its kind on this slice of the sector, and found that in 2015 buyers spent about $642 million on B and C properties in the suburbs, and in 2014, suburban Cook developments alone brought in more than $600 million.

"There is a theory that the suburbs are dying," John Meyer, senior managing director at Kiser, tells GlobeSt.com, mostly due to the migration of local companies into the city. "But every multifamily property I list out there has multiple potential buyers."

Kiser examined the sales of class B or C properties that were built before 1990 and had 100% market-rate units. What brings buyers in, Meyer adds, is the enormous potential for rental growth these properties have. "The older it is, the more upside there is; class A properties have very little upside." Furthermore, "there is no more new supply getting built. And the lack of affordable housing has become a crisis, so class B and C landlords are going to benefit. The amount of desire people have for these classes is never ending."