Other people attending the trial, including interpreters, military paralegals, court stenographers, journalists and legal observers, are housed in a crude trailer park and tent city behind the courthouse, which may have to be expanded.
More construction is under consideration, including shipping modular construction to the base by barge and adding closed-circuit feeds of the proceedings to defense and prosecution offices in Virginia, so some legal staff members can work remotely.
Court spokesmen said no plans were final, and no cost estimates were available.
Even the plan for handling journalists is in flux. The judge has ordered prosecutors to tell him how the Pentagon will handle interest by the news media, which is expected to swell with the start of a trial.
For years, reporters worked out of several wooden sheds that the Navy built inside an old hangar near the courthouse, including a $49,000 staging site for news conferences that transmitted briefings to the United States for journalists not present at Guantánamo. But the roof has been declared unstable and the hangar off-limits to reporters, leaving safe work space for perhaps 20 journalists, down from 60 when the defendants were arraigned in 2012.
Also yet to be decided is how to handle the family members of the 2,976 people who were killed in the Sept. 11 attacks, and a recent expansion of the victim-witness program to include the relatives of rescue workers who subsequently died of diseases related to working at the site of the destroyed World Trade Center.
Last year, trial planners kicked around the idea of, for the trial, eliminating the current system that permits the prosecution to host up to 10 family members and companions at Guantánamo during hearing weeks. Instead, the Office of Military Commissions would pay for transportation, rooms and meals at a viewing location in the United States.
That idea is no longer under consideration, people involved in the process say, but the military is considering adding more closed-circuit viewing sites for family members.