Liberty Mutual’s Headquarters at 175 Berkeley Street expanded the Boston-based company’s campus. The 23-story, 795,000 SF Class A+ office building combines historic elements with innovative new construction. The building’s triangular massing and curved edges respond to the site’s diagonal street grid. An Indiana limestone façade complements the restored Salada Tea historic headquarters, located just across the street. A glass-enclosed pedestrian bridge over Stuart Street links the new building to the existing headquarters, which was also renovated. The new structure includes four stories below-grade with parking and one service level. A two-story cafeteria and two-story conference center provide large spaces for employees.