The nation's spy court is moving from its longtime home at the Justice Department to a nearby federal courthouse, a move that some hope will assert the court's independence even as Congress shifts some of its authority to the Bush administration.

Since its inception in 1978, the Foreign Intelligence Surveillance Court has been located in a secure area at Justice Department headquarters, where government attorneys armed with secret evidence seek permission to conduct surveillance.

"It's always been an anomaly and it suggested to critics that the court was subordinate to its Justice Department hosts," said Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists.

U.S. District Judge Royce C. Lamberth, who presided over the court from 1995 to 2002, agreed the arrangement was never ideal because of that perception. But space at the Washington federal courthouse was scarce until the completion of an annex in 2005.

Workers recently began demolition of the old grand jury rooms, which will be replaced by a new, secure facility for the spy court. Lamberth, the acting chief judge of the federal court this week, said the construction contract had not been signed but expected it to be completed soon. He expects it to cost a few million dollars.

Construction is expected to take several months and the court likely won't be moved until sometime next year. For now, the area is notable only for a padlocked door and signs reading, "Caution. Hard hat area."

The planned move comes after Congress voted earlier this month to strip the spy court of considerable authority. Congress, handing the Bush administration a victory on its terrorism policies, said authorities no longer need the court's approval to eavesdrop on foreigners, even when they are talking to U.S. citizens.

The court's move was already in the works before the law was passed.

"It's a little bit late in the day for symbolism, which is less important than the court's legal authority, which has just been diminished," said Aftergood, whose organization studies the court. "On the other hand, this is a live issue right now and the legislative action from a few weeks ago will be revisited as early as next month. So the court's stature and independence are open policy questions."

David S. Kris, former associate deputy attorney general for national security issues, said having the court inside the Department of Justice is easier for government attorneys, who don't need to bring classified documents up the street to the court. But he said the courthouse may now be better equipped to store such records.

The court at the Department of Justice is much like a conference room but it has been designed and constructed to CIA standards to repel electronic surveillance, according to a description in the book "National Security Investigations & Prosecutions," by Kris and federal prosecutor Doug Wilson.

"There is certainly nothing in the law that requires the courtroom to remain inside DOJ," Kris said. "Normally, of course, lawyers travel to judges, not the other way around."