Future development zones' may only be determined as a consecutive zoning under § 12 section 4 or in the case of rezonings, ruled in § 23 sec. 2 lit. a, Code of Spatial Planning of Vorarlberg. Land, that is not suitable as building zones, must not be zoned in future development zones. Future development zones can be subdivided into core-, residential-, mixed- or operating areas. Residential areas are areas, which are designated for residential buildings. Other buildings and facilities can be errected, if the housing and also otherwise the character as a residential area is not violated.