In 2008, work began on a restoration of the building, after a century without a major renovation. The construction included structural enhancements, upgrades to building services, as well as in-depth restoration of much of the interior and exterior. Due to the complexity of the demands of the project, the New York City Department of Design and Construction hired Hill International to provide construction management. Renovations were originally estimated to cost $104 million and take four years, but ended up costing nearly $150 million and taking over five years.