Building zones in the zoning plan (of a municipality) are built-up areas and areas, that are suitable for building due to the natural conditions and are needed as building zones in a foreseeable time, but within 7 years at the longest, and where services can be provided within that time limit. Building zones must be divided into core areas, residential-, mixed- or operating areas, according to necessity and expediency. Category I operating areas are areas that are intended for operating facilities that do not cause any significant disturbance to the vicinity of the operating area. In the operating area of Category I, the construction of apartments is permitted for those employed in businesses in the area concerned, as well as buildings and facilities that serve the supply and social needs of the population working in such areas. If this is necessary according to the circumstances relevant for spatial planning, zones can be defined in the operating area Category I for the purpose of securing suitable areas for production companies in which buildings and facilities according to Paragraph 6, second sentence lit. a, b or c are not permitted.