And even though "we basically had an equal opportunity bubble burst" across the globe, said Stuart Koenig, global chief administrative officer of locally based Area Property Partners, diversification "will remain paramount in any investment strategy."

But if you're not diverse, multifamily is probably the best sector to place your bets. Adrienne Albert, chief executive officer of Atlanta-based brokerage firm the Marketing Directors, says she is seeing condo transactions increase in Atlanta, Boston, New York City and Washington DC.

Also in the sector's favor is an expected 33% spike in the US population by 2030 and limited supply, said Jonathan Kempner, director of Behringer Harvard Multifamily REIT. "There is very little apartment development today," he said. "There is very little in the pipeline."