adj. Describes employees whose jobs do not require them to work inside an office.
One of the historic aspects of the American office is the looking-over-your-shoulder factor. Bosses are bosses precisely because they—literally and/or symbolically—look over the shoulders of the people who work for them. When you show up for work in the morning, there's someone who looks at you and knows you're there, and what you're supposed to be doing.

This would go away in the new office-free America.
—Bob Greene, “Bosses, workers seem to be going their separate ways,” Chicago Tribune, August 21, 1996
Computer experts and insurance analysts say that severe cost pressures are prompting many companies and industries in the New York region and around the nation to move faster at spinning out their employees as high-tech road warriors. Most notably I.B.M., is about to start an entirely office-free sales force in New Jersey.
—Kirk Johnson, “New Breed of High-Tech Nomads; Mobile Computer-Carrying Workers Transform Companies,” The New York Times, February 08, 1994
1992 (earliest)
The cost of other mobile office gear — portable fax machines cost $ 600 to $ 2,000 and laptop computers that can be plugged into a car battery via the cigarette lighter can cost up to $ 2,500 — makes price another barrier to doing business office-free.
—Julie Bennett, “Highly mobile business people hitting road with offices in tow,” Crain's Chicago Business, May 11, 1992