Minneapolis-based Opus said it will hold an official groundbreaking tomorrow on the five-story building in the Hamilton Lakes Business Park. AAP, which bought the 11.2-acre development site and hired Opus to build its new headquarters, will move into the building in fall 2017, Opus said in a statement. The professional group will vacate its longtime headquarters, a 106,000-square-foot building at 141 Northwest Point Blvd. in Elk Grove Village. About 480 people will work in the new building at 345 Park Blvd., which includes room for future growth. “The AAP’s child health mission is unique, and our new headquarters will serve multiple functions as a home for the profession of pediatrics and our staff,” Dr. Karen Remley, AAP’s executive director and CEO, said in the Opus statement. The new headquarters is one of the biggest built-to-suit office projects in the northwest suburbs over the last few years, and the latest involving a medical group. The American Academy of Orthopaedic Surgeons recently moved into a new 165,000-square-foot headquarters in Rosemont, and the American Society of Anesthesiologists moved from Park Ridge to a new 70,000-square-foot office building in Schaumburg. Chicago architecture firm VOA Associates, now part of Edmonton, Alberta-based Stantec, designed the AAP’s new building. The AAP plans to put its existing Itasca headquarters up for sale, said Roberta Bosak, its director of human resources and administrative services. “It’s been our home for more than 30 years,” she said. “We have just outgrown it.” Eric Kunkel, executive vice president at Jones Lang LaSalle, and JLL Senior Vice President Scott Ohlander conducted the group’s search for a new headquarters and will also handle the sale of the Elk Grove Village property, she said.