Facts
The Swisscom (Schweiz) AG applied to the building authority of Lindau for a building permit for the construction of a new mobile radio system with nine transmitting antennas on a building in Tagelswangen (ZH). The system was to operate on several frequency bands (700–900, 1,800–2,600 and 3,600 MHz) with a cumulative equivalent radiated power (ERP) of 2,195 watts. Three of the antennas in the 3,600 MHz frequency range were designed as adaptive antennas with 16 sub-arrays each, which were to operate with a correction factor (K).
The building authority of Lindau granted the permit on 7 September 2021 subject to ancillary provisions. The decision was appealed by residents [A.] and [B.] to the Building Appeals Court of the Canton of Zurich, which dismissed the appeal on 16 March 2022. The subsequent complaint was also dismissed by the Administrative Court of the Canton of Zurich on 23 March 2023.
On 5 June 2023, the residents filed a complaint with the Federal Supreme Court and requested, among other things, the annulment of the Administrative Court’s judgment and the obtaining of an official report or independent expert opinion on questions regarding acceptance measurements for adaptive antennas. The Federal Supreme Court granted the complaint suspensive effect on 26 June 2023. Swisscom, the Administrative Court of Zurich and the building authority of Lindau requested the dismissal of the complaint, while the Federal Office for the Environment (FOEN) assessed the contested judgment as compliant with environmental protection legislation.
Considerations
1. Admissibility of the complaint The Federal Supreme Court examines the complaint in public law matters (Art. 82 lit. a, Art. 86 para. 1 lit. d and para. 2, Art. 90 FSCA) and admits it since the complainants, as owners or residents of a property within the objection perimeter, have a legitimate interest in the annulment of the judgment (Art. 89 para. 1 FSCA). The substantive requirements for a judgment on the merits are met.
2. Examination of the legality of the provisions on adaptive antennas in the NIRO: The complainants challenge the legality of the correction factors for adaptive antennas regulated in para. 63 paras. 2 and 3 of Annex 1 to the Ordinance on Protection against Non-Ionising Radiation (NIRO; SR 814.710). The Federal Supreme Court examines the ordinance incidentally for its conformity with the law and the constitution. The Federal Council has the regulatory competence pursuant to Art. 38 para. 3 EPA, and the provisions do not exceed the statutory framework. The regulation is appropriate to the level of legislation and enables rapid adaptation to new technical developments.
3. Compatibility with the precautionary principle (Art. 11 para. 2 EPA) The complainants object that the correction factor leads to a lowering of the protection level since the transmitted power no longer has to be maintained at the maximum but must be complied with as an average over 6 minutes. The Federal Supreme Court notes that adaptive antennas cause a lower average radiation exposure than conventional antennas since the transmitted power is specifically directed at users. The correction factor prevents excessive exposure due to short-term power peaks and maintains the safety margin relative to the emission limit values. The regulation sufficiently takes account of the precautionary principle.
4. Quality assurance system (QA system) and acceptance measurements The complainants criticise the QA system as unsuitable since it does not provide for real-time monitoring of the transmitted power or mapping of the antenna diagram. The Federal Supreme Court refers to the FOEN’s enforcement recommendations, which provide for additional parameters such as the operating mode, the correction factor and automatic power limitation. The QA system is suitable for monitoring compliance with the approved operation of adaptive antennas.…