Single-family homes weren’t the only housing type severely impacted by the economic downturn, new research shows. According to a new study from Citizens Housing & Planning Council, over-mortgaged and foreclosed multifamily buildings increase the risk of deterioration of nearby buildings and raise costs for private owners and the city in the form of additional Emergency Repair Program expenditures. … Harold Shultz, senior fellow at the CHPC, tells GlobeSt.com that he hopes the study will raise awareness about the distressed multifamily market.