Legal Question in Real Estate Law in New York

You have rights. Did he contribute to payment? Is his name on the deed? if yes then seek a buy out or sell the house or if he refuses, then start a partition action.

I agree with Yefim. Possibly, your rights may be slightly larger since you own the land on which the house was built, and if his name was never put on the Deed. You might even have the right to charge rent for a land lease until the house is sold. I suggest contacting a good local attorney familiar with real estate law to assist you.