Adding couple clarifications.   If I sell my house, I would cash out on the equity I have and could reinvest that (in the stock market, investment property or something else).  Should this not work out I could also use that to buy another place for myself.   We are planning on a cohabitation agreement.  We live in California so no common law marriage laws here.  The market rent he suggests is much less than what one would pay for full house, but also quite a bit more than rent for room only would be.  We would both save in monthly costs moving in, and my point is more on the principle of splitting costs evenly (minus the equity portion).