(appeal from circuit court review of administrative opinion denying just compensation for landowners due to environmental law prohibiting additional home-building; just compensation allowed waiver of post-acquisition land use regulations resulting in approval of up to three permits for homesites on property; just compensation premised on petitioners’ authorization for additional dwellings at the time of acquisition under existing laws; petitioners, however, were unable to establish they planted perennials capable of generating $10,000 in annual gross income which is a statutory prerequisite for entitlement to dwelling on less than 20 acres; court held petitioners were required to establish prerequisites were met prior to change in law; just compensation did not allow entitlement to attempt to meet historical standards; circuit court order reversed and agency decision reinstated).