The master's thesis deals with the prevalence of the widespread use of the site verification instrument in Slovenian municipalities. Spatial development of municipalities is defined by the production of spatial acts but the process of changing spatial planning acts is normally very time-consuming. Changes to spatial acts, even with the prescribed procedures, are generally time-consuming, and as a result, responsiveness to potential new needs in the space is also slow. This way of organizing the space is quite rigid. Over time, practice has shown that there is a need for a certain degree of forecasting in spatial planning and the possibility of adaptation to specific investment needs. With the site verification instrument, municipalities can make minor changes to the implementation of the space based on individual needs in the environment. In order to preserve individual settlements, they can transform or change the extent of building land, as specified in the OPN and adjust the spatial implementation conditions. In order to achieve the construction purpose, individual deviations from the spatial execution conditions may be permitted, as specified in the OPN. They can also enable the temporary use of space for the purpose of efficient use and activation of land and buildings that are not in use. The prevalence of the site verification instrument was studied on the basis of data obtained from the Ministry of Environment and Spatial Planning and a survey questionnaire, which was sent to all Slovenian municipalities. We have processed all the data and form an opinion about the widespread use of the site verification instrument and other findings. We made study of the site verification instrument for specific testing area to better understand the process.