Bill of Rights Scenario- Eminent Domain

Mary and John have owned a second house in Florida for 10 years that has been vacant for about 5 years. They have it for when they want to vacation in Florida, but they haven't had a chance to use it. The government has been wanting to build a courthouse next to their property, but they need extra space. The extra space would require the government to tear down the fence surrounding the property and using part of the land. Mary and John don't want to sell part of their property, but the government plans to tear it down anyway and build the courthouse.