Mayor Marty Walsh and Larry Curtis, president of WinnDevelopment, visited the Castle Square community in Boston's South End for a celebration of Black History Month and Chinese New Year recently. In 2012, Castle Square underwent the nation's largest Deep Energy Retrofit of an existing multifamily property. This resulted in substantial energy savings and a spot on ENERGY STAR's inaugural list of certified multifamily communities in November. Winn is the nation's largest affordable housing manager and 5th largest manager overall.