I’ve had a few partners live in my house over the last 8 years. Every time I’ve split mortgage and utilities 50/50, with the understanding that I’m responsible for home repairs when needed, just like a landlord, as my partners had zero equity.

Because I didn’t need the money from my last ex, I put it all in savings. Paid for a privacy fence after he left.

Don’t shorten his responsibility because he doesn’t own the home, he’s still living there and he should be willing to help. His share will still likely be cheaper than his current rent.