Specifics about the third phase, which initially was to involve renovations to older buildings, long remained undisclosed. In November 2009, plans were made public that LACMA's director Michael Govan was working with Swiss architect and Pritzker Prize laureate Peter Zumthor on plans for rebuilding the eastern section of the campus, the Perreira Buildings between the two new Renzo Piano buildings and the tar pits. Architecture firm Skidmore, Owings & Merrill collaborated with Zumthor on the building's design. With an estimated cost of $650 million, Zumthor's first proposal called for a horizontal building along Wilshire Boulevard. It would have been wrapped in glass on all sides and its main galleries lifted one floor into the air. The wide roof would have been covered with solar panels. In a later concession to concerns raised by its neighbor, the Page Museum, LACMA had Zumthor alter the shape of his proposed building to stretch across Wilshire Boulevard and away from the La Brea Tar Pits.