I don't think I want him to do this -'out of the kindness of their [his] heart'.
I want him to do this because he is an adult who has the same responsibility as I do. This has nothing to do with kindness.
When I am doing it, nobody talks about "kindness", everyone can tell that it's my job and so is his. Esp since I am the one having a job.

But I think deviding up chords might help. We tried with a list were you are free to choose, so there is a written form for this, but it seems it's not enough.

@littleCat thanks for your advise, too! But I refuse to treat an adult like a child, esp when I know that when he was living alone, he was capable of doing all this.

So it seems it's more a question of not feeling responsible.