A sale of that one person's interest in the property can be done through the judicial system. It is called a partition of realty or property. Generlly one sibling suing the others (which is what a partition of realty is) tends to bring out the nasties in everyone. Other than that, we can't predict the future here for you. You can also agree to have a neutral real estate appraisal of the property. Then, assuming there is sufficient equity in the home, re-fi the property to pay off the one heir/sibling. Then the 4 of you will have to equally share in the payoff of that mortgage.