In Switzerland, strict limits apply with regard to non-ionising radiation. These are regulated in the Ordinance on Protection against Non-Ionising Radiation (NISV) and regulate the magnetic fields generated by transformer stations, as well as cable and overhead lines. The PR-NIS of the City of Zurich goes one step further and also considers sources within buildings from domestic installations such as risers and electrical distributions.

NISV

The Ordinance on Protection against Non-Ionising Radiation NIR (SR 814.710) has been in force in Switzerland since 1 February 2000. Its purpose is to protect people from harmful or annoying non-ionising radiation generated by fixed installations. It specifies immission limit values (IGW) and an installation limit value (AGW) for precautionary emission limitation. The immission limit values must be complied with everywhere, where people could be present. The installation limit value must be complied with at high-voltage installations such as cable and overhead lines, transformer stations, substations and switchgear as well as railways and tramways, in places with sensitive use.

Places with sensitive use are defined as places where people spend more than 4 hours per day or 800 hours per year, as well as public or private children’s playgrounds established under spatial planning law. Workplaces that are occupied for more than 4 hours per day, even if this is not exclusively by one and the same person, are also considered to be places of sensitive use. Furthermore, the installation limit value must be complied with for undeveloped areas in which places of sensitive use may arise.

In the case of transformer stations, all live parts of the station, including the low-voltage connection and the low-voltage distribution board, are considered an installation. Therefore, they must be taken into account in the calculation. The decisive operating condition is operation at nominal load.

PR-NIS

With the planning guideline on non-ionising radiation (PR-NIS), the City of Zurich intends to treat all basic building installations in city-owned buildings according to uniform specifications with regard to their electromagnetic emmissions, in order to create equal conditions for all users.

The planning guideline regulates the maximum emissions depending on the type of use of buildings and outdoor spaces. The sources of non-ionising radiation are technical equipment such as electrical installations, electrical distributors, transmitters, etc. In order to be able to comply with the limit values of the PR-NIS, the guideline provides planning and installation instructions. The PR-NIS does not make any specifications for limiting radiation from mobile devices (PCs, printers, mobile telephones).

The planning guideline deals with electromagnetic emissions in the frequency range between 0 – 300 GHz (non-ionising radiation). This planning guideline must be implemented in all new buildings.

The requirements for emission limitation depend on the use. In principle, higher requirements apply to places where people usually spend longer periods of time than to places where people usually spend only short periods of time. The following types of use are distinguished:

User zones B are considered to be:

  1. Rooms in buildings where people regularly stay for longer periods of time.
  2. Areas of undeveloped land on which uses in accordance with letters a. are permitted.

User zones A are places which are classified as particularly sensitive, e.g. crèches, nurseries, kindergartens,pla ygrounds and bedrooms.

The PR-NIS also applies to Minergie-ECO certified buildings throughout Switzerland.