In Switzerland there are numerous public law restrictions on landownership. In the initial phase of its development, the 17 most important restrictions from eight sectors in accordance with federal legislation were incorporated into the PLR Cadastre by 2020, and six more restrictions will be added by 2023.

Spatial planning | Roads | Railways | Airports | Contaminated sites | Water | Noise | Forests | Supply and disposal

Spatial planning

• Land use plans (cantonal/municipal)
  Land use plans (which are often also referred to as zoning plans) specify the type and use of the land. They divide an area into various zones (building, agricultural, conservation). Decisions relating to each zone are normally taken at the municipal level, and have to be subsequently approved by a cantonal authority. After they have been officially approved, land use plans become legally binding.
• Planning zones (new, in preparation)
  Planning zones encompass a designated area for which a land use plan has to be adapted or does not yet exist, and within which no action may be taken that could hamper the land use plan.
  

Roads

• Reserved zones for motorways
  Reserved zones can be defined in order to ensure that the land required for the construction of the motorway/national roads network remains available. In these zones, without a special permit it is prohibited to construct new buildings and carry out alterations that result in increased value.
• Building lines for motorways
  Once the plans for a route have been finalised, building lines are defined along both sides of that route. These lines make it possible to take certain requirements into account, including road safety and public health, as well as the demands associated with the potential future widening of the stretch of road. Without a special permit, the construction of new buildings is prohibited between these lines, as is the renovation of existing structures, even if they only partially protrude into the building lines.
• Building and distance lines outside the scope of land use plans (new, in preparation)
  For example, building lines along cantonal roads and municipal roads in accordance with cantonal legislation. 

Railways

The railway network provides services that can be used by everyone for the transport of passengers and goods, as well as vehicles.

• Reserved zones for railways
  Reserved zones may be specified for precisely defined areas in order to ensure that the necessary land for the future construction of railway stretches and installations is kept in reserve. In these zones, no structural alterations may be carried out that do not correspond to the purpose specified by the railway operator.
• Building lines for railways
  Building lines may be specified in order to ensure that the necessary land for the ongoing or future construction of railway stretches and installations remains available. No structural alterations or other measures that do not correspond to the specified purpose of the railway operator may be carried out either between the building lines or between a building line and a railway installation.  

Airports

An airport or airfield is a designated zone on land or water. It includes the buildings and facilities required for take-offs and landings, as well as for the maintenance and parking of aircraft.

• Reserved zones for airports
  In order to ensure that airports have the necessary land at their disposal for their various facilities, project zones can be defined, the boundaries of which have to be clearly specified. Within these zones, no structural changes may be carried out that conflict with the purpose of the airport facilities.
• Building lines for airports
  Building lines for airports may be defined in order to ensure that airports have the necessary land at their disposal for existing or future facilities. Within these building lines, no structural changes may be carried out that conflict with the purpose of the defined building lines.
• Security zone plan
  Every airport is required to designate a security zone. The Federal Office of Civil Aviation (FOCA) is responsible for deciding on a case by case basis whether a security zone is required for air traffic control systems and flight paths. Without the consent of the applicant, no one may own property that is subject to a security zone plan.

Contaminated sites

The cantons are responsible for ensuring that landfills and other sites that have been contaminated by waste are properly cleaned up if they give rise to harmful effects or pollution, or if there is a specific risk of their doing so. The relevant authorities identify contaminated sites by evaluating existing maps, directories and reports. Those sites that are found to be (or are very probably) contaminated are listed in the corresponding cadastre:

• Cadastre of contaminated sites
• Cadastre of contaminated military sites
• Cadastre of contaminated civil aviation sites
• Cadastre of contaminated public transport sites

Water 

The objective of federal legislation governing the protection of bodies of water is to ensure that they are protected against pollution and other undesirable effects. Its main purposes are to safeguard the health of human beings, protect flora and fauna, secure the economical use of drinking and process water, and preserve the natural function of the water cycle.

• Groundwater protection zones
  The cantons define groundwater protection zones for the supply and treatment facilities that are in the public interest, and specify the necessary landownership restrictions.
• Groundwater protection areas
  The cantons define sites that are of significance in terms of the future use and treatment of groundwater reserves. At these sites, no buildings or installations may be constructed, and no work may be carried out, that could interfere with the future construction of groundwater utilisation and treatment facilities.
• Space provided for waters (new, in preparation)
  Flowing bodies of water can only be preserved in their natural state if sufficient space is reserved for their protection. Watercourse corridors must be kept free from new installations, though existing structures may be retained.
  

Noise

The Noise Abatement Ordinance is intended to protect against harmful and disturbing noise.

• Noise sensitivity level (in land use zones)
  In land use plans, sensitivity levels are specified in order to define certain zones, namely those in which increased noise abatement measures are required, those in which no activities are permitted that result in disturbance due to noise, and those in which activities are permitted that give rise to medium to high levels of noise. 
  

Forests

The forest Act is intended to conserve the forest in its area and spatial distribution and also to protect the forest as a near-natural community. Further it is intended to ensure that the forest can fulfil its functions, in particular its protective, social and economic functions.

• Static forest perimeters
  Static forest perimeters have to be defined on the basis of legally binding declarations of forested areas. Newly planted trees outside the defined forest perimeter are not regarded as forest.
• Forest distance lines
  Buildings and installations are only permitted near a forested area if they do not interfere with the preservation, management and use of the forest. Based on legally binding forest boundaries, the cantons define an appropriate minimum distance between buildings and facilities and the forest perimeter. The minimum distance is defined while taking the location and the anticipated height of the trees into account.
• Forest reserves (new, in preparation)
  Protected forest land for the purpose of preserving the diversity of fauna and flora. 

Supply and disposal

• Reserved zones for power lines with a nominal voltage of 220 kV or higher (new, in preparation)
  Reserved zones may be specified in precisely designated regions in order to secure the availability of the necessary plots of land for the use of power lines with a nominal voltage of 200 kV or higher. In these zones, no structural alterations may be carried out that could interfere with the specified purpose of the power lines.
• Building lines for high-voltage installations (new, in preparation)
  Between the designated building lines, no structural alterations may be carried out or other measures implemented that could interfere with the specified purpose of existing or future high-voltage installations.

The cantons may add their own legally binding landownership restrictions if they meet the following requirements:

• They must safeguard public interests
• They must be clearly defined in spatial terms (i.e. have a distinct geometry, for example surface area, line)
• They must have a certain duration of applicability, even if they should be subject to a time limit (at least two years)
• They must fully comply with the applicable federal legislation