OUT WITH THE OLD . . . Robert and Arlene Kogod, prolific Washington philanthropists and art collectors, yesterday gave the Smithsonian Institution $25 million toward the renovation of the historic Patent Office Building.

The gift is the fourth largest donation in Smithsonian history and the biggest since the Donald W. Reynolds Foundation gave $30 million in 2001.

The Kogod money will enable the museum to proceed with a dramatic glass enclosure over the courtyard of the building, which will reopen in 2006 as the restored home of both the Smithsonian American Art Museum and the National Portrait Gallery.

This is the Patent Office project's third major gift. Nan Tucker McEvoy and the Henry Luce Foundation each donated $10 million in 2001.

A National Historic Landmark, the Patent Office building -- across Seventh Street NW from MCI Center -- has been closed to the public since 2000 and has been gutted. Much of the contents of the American Art Museum and the National Portrait Gallery have been put on the road in traveling shows. The renovation, designed by Hartman-Cox Architects of Washington, is scheduled to be completed by July 4, 2006.