Boston University unveiled designs for a new academic building that would become the tallest mass timber tower in Massachusetts. BU’s Pardee School of Global Studies would occupy the 12-story tower at 250 Bay State Road, consolidating classrooms and offices spread across the Charles River campus. With a height of 186 feet, the 70,000-square-foot building maximizes the height allowed for wood-framed buildings under the International Building Code, according to a project filing submitted to the Boston Planning Department. The university envisions the project as a leader in minimizing the use of embedded carbon in building materials. Embedded carbon has become a recent focus of regulators’ efforts to reduce the use of greenhouse gases during manufacturing of traditional construction materials such as steel and concrete. Mass timber projects typically use manufactured wood panels.