If you should accept this mission, according to http://www.ci.boston.ma.us/rentalhousing/pdfs/handbook.pdf , it looks like you could just live in this house. There are a number of rules for tenant-landlord relationships, but non-tenant relationships are not really addressed. (There does seem to be a weirdness about the water bill. I may have to continue to pay it (i.e., the bill has to be addressed to the owner), but I'm not certain.) Also, you'd be responsible to virtually everything in the household, including snow removal. ('Though, for snow removal, I'm liable for accidents, etc.) I'm still looking into getting this place appraised.