These serve to keep the banks of streams, rivers and lakes, forest edges, vantage points, the terrain for practising winter sports and the protection of groundwater and spring water protection zones outside the settlement area free of obstructions.

The construction of buildings and installations that correspond to this zoning purpose is permitted here.

At the national level, a distinction is made between three zones: Building zones, agricultural zones and protection zones.

Cantonal law may provide for further use zones; for example, there are five types of zones in the Canton of Zurich. In addition to the free zones, building zones, agricultural zones, recreation zones and reserve zones are also defined and regulated as such.