Kilroy Realty Corp. has started construction of a 700,000-square-foot, $485 million project in the Mission Bay submarket consisting of two six-story and two 12-story office and life science buildings. The Exchange on 16th’s four interconnected buildings will align to provide three "super floors" of up to 95,000 square feet. Kilroy is targeting LEED platinum certification for the building, which includes floor plates with high ceilings, natural light and views of the bay.