I also worked with a technical writer who was also a professional jazz musician. He would rise mid-afternoon, write until about six, and then come in to the office to talk to the development team for an hour or so. Face time is important for the employee, the team, and the project manager. I'm not talking about conducting that institutionalized waste of time, the status meeting. I'm talking about the social interaction that comes with sharing space with other people.
Home workers can suffer from cabin fever.
A good antidote is a regular lunch date for the team. It's a great way of keeping them together. When someone asks if they can work from home you'll have to decide with them how often they will put in an appearance in the office. This is key to their success, and there are no general rules. Both of these cases might need too much supervision to be good candidates for home working.