Selling houses is a very formalized process, this should be easy to enforce. First of all, there is a deed of sale that gets signed over, the unsuitability for

Selling houses is a very formalized process, this should be easy to enforce. First of all, there is a deed of sale that gets signed over, the unsuitability for resale could be listed on the deed. Remember selling a house usually is a super involved process that costs 10s of thousands of dollars. It almost sounds to me like you don't WANT to find a better solution.