I am a developer in a small company (~15 people). We are allowed to work remotely on some occasions (health, appointments, weather, etc.), but not on a regular basis.
I enjoy working from home for a lot of reasons (family, productivity, flexibility, ...). I have already approached my manager about a year and half ago, saying that I would like to work remotely more, but I have been denied on the grounds that other employees would want that too and since we are small that would mean that the offices would empty and the "company spirit" would vanish (not something I personally agree with).
I now wish to work remotely most of the time and it has become a very strong wish for me. Strong enough that I would quit my current job over it. However I like working there and I don't want to quit without giving them a chance to fulfill my request. On the other hand, I don't want to threaten to quit (or imply it, especially since another coworker did quit over this issue some time ago) and I actually like working there.
My plan right now is to build a case on how I'm able to work from home, and in which way it would be beneficial for everyone, then present it to my manager. I have some points for me : they are very satisfied of my performance and I actually live close enough that I can still show up to meetings or in an emergency. I can also compromise on coming to the office one or two days a week.
How can I present my case in a way that isn't threatening, while driving the point that it is very important to me ?