The master's thesis discusses the area of specifying and registering functional building units of building lands. This is one of the most important areas from the point of view of implementing active land policy, area management, and real estate taxation. Area management and land policy are not regulated satisfactory, not even in urban areas, which reflects negative phenomena and trends that restrain, both economic as well as social development of the country. Another big issue is the lack of the developed land and building but not built on land data which represent vital spatial potential and have the key role in land policy. The master’s thesis examines in detail the history of specifying and registering building lands and building plots. In addition, it also represents the tasks implemented in recent years in the area of registering buildings’ appertaining areas, building land developmental levels and the actual use of urban area. Proceeding from this, the practical part of the thesis tests in detail the suggested methodology on chosen study cases. Based on the results some legislative solutions in the area of specifying and registering functional building units in the land cadastre were suggested. The conclusion for the long-term solution, even for registering building land data, is establishing the multipurpose cadastre which would coalesce all the necessary spatial and descriptive data in one place, and thus be the basis for vital directions in developmental processes and spatial arrangements, real estate evaluation and taxation, etc.