Facts
On 9 March 2017 the Rüschlikon municipal building commission granted the building consortium X. (consisting of A., B. AG and C. GmbH) a building permit for a multi-family house with eight apartments and an underground garage at Seestrasse 88 in Rüschlikon (parcels Nos. 5237 and 2589, residential zone W3). On the same day, C. GmbH and B. AG were granted a building permit for the demolition of existing buildings and the construction of a multi-family house with seven apartments on the rear parcel No. 3965 (Mühlestrasse 29/29a, residential zone W2A). The cantonal overall decisions of the Zurich Directorate of Public Works were in place.
D., owner of the adjoining parcels Nos. 5236 and 5238 to the north, filed an appeal. The Zurich Building Appeals Court dismissed the appeals by decision of 21 November 2017. The Administrative Court of the Canton of Zurich upheld the complaint by judgment of 18 December 2019 and annulled the building permits and overall decisions.
The building owners lodged a public law appeal with the Federal Supreme Court, requesting that the Administrative Court's judgment be set aside and the Building Appeals Court's decision be confirmed, or alternatively that the matter be remitted. The Administrative Court and the respondent requested dismissal, the respondent alternatively remittal. The Directorate of Public Works and the building commission requested that the appeal be upheld. The Federal Office for the Environment (FOEN) considered the contested decision to be in compliance with noise protection law.
The question in dispute was whether the construction project on Seestrasse, which lies in sensitivity level II, could be approved under noise protection law by way of an exceptional permit pursuant to Art. 31 para. 2 NAO. Noise exposure at the east facade was 66 dB(A) during the day and 60 dB(A) at night, compared with immission limit values of 60 dB(A) by day and 50 dB(A) by night.
Considerations
The public law appeal is admissible against the final cantonal decision (Art. 82 let. a, Art. 86 para. 1 let. d, Art. 90 FSCA); the appellants are legitimised as building applicants (Art. 89 para. 1 FSCA). Pursuant to Art. 22 EPA and Art. 31 NAO, building permits for new noise-sensitive buildings may only be granted if the immission limit values can be complied with. If this is not possible through the arrangement of rooms or structural measures, an exceptional permit under Art. 31 para. 2 NAO is only admissible where there is a predominant public interest and with the consent of the cantonal authority, whereby a balancing of interests takes place. Private interests of the owner in a better use alone are not sufficient.
The Federal Supreme Court rejected the claim that a breach of good faith or legal certainty arose from a change in practice. Judgment 1C_106/2018 of 2 April 2019 did not tighten the requirements but merely clarified the existing interpretation. Moreover, the question of the examination of measures concerns a substantive and not an admissibility question for legal remedies, so no protection of legitimate expectations applies.
The Federal Supreme Court dismissed the complaint of manifestly incorrect establishment of the facts (Art. 97 para. 1 FSCA, Art. 9 Cst.). The finding that apartments were planned with as many living rooms as possible oriented towards the lake was not arbitrary; at its core the matter concerns the interpretation of Art. 22 EPA and Art. 31 NAO. The strict principle of complaint (Art. 106 para. 2 FSCA) was not complied with in respect of further complaints.
On the merits, the Federal Supreme Court held that an exceptional permit can only be considered if all proportionate structural and design measures have been exhausted (ultima ratio). The burden of proof lies with the building applicant; where limit values are substantially exceeded, an in-depth examination of measures is required. The lower court rightly found that the measures (cantilevers, sound-absorbing ceiling underlayers, balcony parapets) were predominantly substitute measures and that no floor plan optimisation had been demonstrated. The noise expert report addressed the preconditions only in the abstract, not the concrete measures; a noise protection…