I own a house, no more mortgage. My fiancé has a house on the water that needs repair and updating. He wants me to have my name on the deed, and we would re-finance together but using a large portion ($50K) to do the updates. He still says I will pay half the mortgage because the value of the house supersedes the value of my current home by twice that amount. Is this fair?

Keep in mind if he loses his job or dies you will be on the hook for 100% of the mortgage.

How much is the refi and how much is the current assessed value?

Definitely DON'T do this without your name being on the deed. THis way if you break up down the road you can force a partition sale and get back at least some of the money you would be paying. And make sure there is no prenup or anything in writing that gives you any less than 50% of its value (or of the equity).

I don't se how the value of his house versus the value of your current house has any bearing on this at all - if your name is on the deed you are a half-owner, and I agree with SG that you certainly don't want to be obligated to pay the mortgage on a property if your name is not on the deed. I do believe it's fair for you to pay half the mortgage if you own half the house.