I own my home and if someone were to move it. I would like to split stuff 50/50. Cover all the repairs of course and probably in the end cover a bit more of the utilities. The "rent" I would get would go into a separate account and be saved. Cover the honeymoon or down payment on a better house. I also would only be looking at what my current expense is and not the market rate. My mortgage is $600 but I could rent the place out for $1500. No way am I charging a partner $750. It would also be a discussion with my partner about living agreements before they move in. It be, we are both saving money living together. Show my mortgage is x and that 50% is y. Splitting 50/50 is cheaper than renting and helps with any repairs that come up.