The main outpout of this case is that the precautionary principle (article 5 of the Charter for the Environment), mentioned in the Preamble of the Constitution according to the constitutional law of 1st March 2005, does not require additional legislative or regulatory measure. Article 5 of the Charter is considered to bind public authorities and administrative authorities when they take a decision in their respective fields of competence.  The applicant claimed the annulment of the mayor’s decision to grant a building permit for the construction of telephone relay antennas.

The Conseil d’Etat reminds that Article 5 of the Charter for the Environment provides that when a damage may impact the environment, competent authorities, according the precautionary principle, must implement risk assessment procedures and adopt interim and proportionate measures. It does not require additional measures. As a result, the precautionary principle must be taken into account by the administrative authority when it grants a building permit. The Conseil d’Etat also states that the judge control only the manifest error of assessment in this area.

Consequently, the Conseil d’Etat overturns the judgement of the administrative tribunal that does not comply with that. However, the Conseil d’Etat rules that in the state of scientific knowledge on risks of human exposure to static electromagnetic fields and radiation by relay antennas, the mayor took a decision according to article 5 of the Charter for the Environment.  His decision is not vitiated by a manifest error of assessment.