Homestead exemption with co-owner that has joint tenancy/right of survivorship

[octoblonde]

I'm in NY state, and if I file, can use either NY or Federal exemptions. I co-own a house with joint tenancy and right of survivorship. The other party is not filing BK. My question is do I need enough homestead exemption for ALL of the equity in the house (which is only about 25 or 30K before selling costs) or do I only need enough exemption to cover my half of the house? Would the trustee be able to take the co-owner's share of the property? The reason I ask is because I may need part of the unused homestead exemption to cover equity in a vehicle that is owned outright.

Thanks for any insight you can offer!