Catherine: I too am sorry about this difficult situation. Of course you will help your BIL because neither you nor DH have it in you to ignore his plight. However, I do feel strongly that you shouldn't go so far as to take on another mortgage to buy a property in which to house him; that would seriously undermine your own financial situation. As far as it being a good investment, it also doesn't sound like you and DH are really cut out to be landlords. Can you comfortably afford another property, even without steady rental income? Will you be OK with evicting a tenant who has a legitimate hardship situation and cannot pay the rent? I certainly don't mean it as an insult, but I think you are too soft-hearted to be a landlord.