Space is a limited resource and due to the large increase in the number of inhabitants in cities in a relatively small and limited space, there is a problem of overcrowding. Free construction land is limited, the so-called greenfield area and came up with the idea of restoring unused areas of the brownfield. This final work deals with the topic of brownfields, which in urban planning means abandoned and unused areas or land that are not used for the purposes for which they are intended. Most of them are buildings that were used for industrial, tourist or commercial purposes. Cities in developed countries are increasingly focusing on the restoration of brownfield areas and conversion because they face a large number of unused areas that often occupy attractive locations in city centers. The existence of such abandoned industrial areas in cities has adverse effects, such as deterioration of aesthetic appearance and poor environmental impact because these are often areas where there is a problem of pollution. Therefore, it is also very important to maintain a healthy urban environment of cities because it is a prerequisite for improving the quality of life of people and a cleaner environment. One of the solutions that is being considered and increasingly applied in Croatia is the conversion of existing buildings that are unused and abandoned, which is a consequence of socio-economic changes in the 90s of the last century and / or war. A brownfield register is being developed in Croatia, which will publicly provide an overview of all brownfield areas that have the potential for reconstruction, such as the abandoned tourist military resort in Kupari.