I work in a company that allows to work from home 20% of the time. Currently I do it once a month (on average), because my manager prefers when everyone is in the office (it's easier to communicate with colleagues then). Asking to work from home usually requires providing a good reason, e.g. a private appointment in the middle of the day, expecting a big package, a plumber coming to repair the sink or something similar. I tried asking for home office a few times without providing a reason, and my manager didn't explicitly reject the requests, but he wasn't very happy with it.
I enjoy working from home for many reasons: my place looks way nicer than the office, I can do sport during the lunch break, I can start and finish working earlier, because I don't need to travel to work etc. There are days when I have no meetings and a lot of work to do that doesn't require talking with colleagues. So I would like to do home office a bit more often (maybe 3-4 days a month), but I'm afraid to ask my manager if I can work from home just because I would like to.
How can I discuss it with him? I don't want to give him the impression that I want to abuse this possibility and get less work done, or that I don't like collaborating with colleagues, or whatever his concerns are.