This Diploma Thesis aims on providing a comprehensive overview of an issue re- garding the occupancy of buildings and alterations of the occupancy of buildings. Con- cerned piece of work is divided into eleven chapters in total further structured into sub- chapters. First chapter contains legal sources governing the issue of the occupancy of build- ings and alterations of the occupancy of buildings. The most important legislation con- cerning the issue is listed. This chapter fluently flows into the second chapter which ex- amines next-to-last amendment to the Building Act discussed frequently in the public. At the same time, this chapter establishes seven points to rationalize amendments to the legislation which are accepted positively by ...