When writing software documentation, it's usually not necessary to work permanently onsite within the rooms of my clients. Most tasks can well be accomplished within my own office. To do the required research and to discuss the project, I usually visit my clients a limited number of times. Also we can use Skype and the telephone.
As I use my own hardware and software (e.g. Madcap Flare, Help & Manual, Doc-To-Help, RoboHelp, Confluence, FrameMaker, Microsoft Word, Captivate, Camtasia, DemoBuilder), my clients don't have to provide a workplace and the only costs involved are those for my hourly fee.