A Brooklyn-based property owner has filed applications for a six-story, 19,144-square-foot medical building at 849 53rd Street, located in Sunset Park. The building will rise 69 feet and medical offices will be located across the ground through sixth floors. Qiang Su’s Flushing-based firm is the architect of record. The 40-foot-wide, 4,007-square-foot assemblage is occupied by two two-story rowhomes. Demolition permits were filed for both in December.