Facts

Parties and courts: The appellant, owner of a block of residential buildings located at 1, 3 and 5, rue des Ronzades and 14, rue Gustave-Revilliod in Geneva (parcels nos 1372, 1373 and 1374, municipality of Geneva, Plainpalais section), contests its registration on the Geneva architectural inventory. She is represented by a lawyer. The respondent authority is the Department of Territory of the Canton of Geneva, Office of Heritage and Sites.

History of the building: Built in 1956-1957 by two architects, one of whom enjoyed a certain reputation in the Swiss architectural landscape of the time, the building is referenced in several works on twentieth-century architecture. It presents an original structural solution, new typological proposals (cross-ventilated apartments of two or three rooms, and four-room duplexes served by walkways) and reflects the major international trends of the period.

Administrative procedure

  • 28 October 2003: the Cantonal Commission for Monuments, Nature and Sites (CMNS) approved a proposal from its working group to register the building on the inventory.
  • 11 November 2005: opening of a registration procedure by the Monuments and Sites Service.
  • 21 February 2007: favourable opinion of the City of Geneva.
  • 21 December 2011: the CMNS decided to complete the registration procedures for the objects on its list.
  • 9 April 2014: architectural survey sheet for the Praille-Acacias-Vernets sector assigning the building the rating 'interesting', validated by the CMNS on 28 May 2014.
  • 5 December 2016: notification of the owner and invitation to submit observations by 30 January 2017; no observations were filed.
  • 4 April 2017: decree of the Department of Territory registering the building on the inventory.

Cantonal procedure: The owner appealed to the Administrative Chamber of the Geneva Court of Justice, which conducted a local inspection on 18 May 2018 and dismissed the appeal by judgment of 18 December 2018 (ATA/1354/2018).

Federal procedure: The appellant filed a public law appeal, principally seeking annulment of the cantonal judgment and of the decree of 4 April 2017, and subsidiarily remittal of the case for determination on the merits and an expert assessment of the building's architectural value. The Department seeks a finding that the claims directed against the decree are inadmissible (full devolutive effect) and confirmation of the cantonal judgment.

Main question: The Federal Supreme Court must examine whether the cantonal court violated the right to be heard (refusal of an expert assessment), arbitrarily applied cantonal law (the 18-month time limit of Art. 7 para. 4 LPMNS and the existence of an opinion of the CMNS within the meaning of Art. 47 para. 1 LPMNS), and violated the guarantee of property (Art. 26 Cst.) on account of an absence of public interest or the disproportionality of the measure.

Considerations

Admissibility: The appeal is directed against a final decision (Art. 90 BGG) rendered as the last cantonal instance (Art. 86 para. 1 let. d BGG) in the field of protection of monuments and sites (Art. 82 let. a BGG). The owner, being particularly affected, has standing (Art. 89 para. 1 BGG). Her claims directed against the decree of 4 April 2017 are, however, inadmissible because of the full devolutive effect of the cantonal appeal (Art. 67 AniWA/GE; ATF 136 II 101 consid. 1.2). For the remainder, the appeal is admissible.

Right to be heard (Art. 29 para. 2 Cst.) and refusal of an expert assessment: The right to evidence does not prevent the authority from closing the investigation where the evidence already taken has enabled it to form its view and a non-arbitrary anticipatory assessment ensures that the proposed evidence would not alter its opinion (ATF 140 I 285 consid. 6.3.1). In this case, the file contained numerous descriptive and written documents by various authors, and the architectural features were observed during the local inspection by the specialists present. The case law invoked (judgment 1C_52/2016) concerned an expert assessment of the cost of works and not the existence of architectural value. The fact that opinions emanate from the CMNS and from an architect who is a member of it is not sufficient to render them non-objective. Finally, the appellant requested an expert assessment only as to architectural or historical value, not market value; the cantonal court implicitly dispensed with an expert assessment by holding that the registration would ensure an acceptable return, which the appellant does not contest. The complaint is rejected.

Arbitrary application of cantonal law (heightened reasoning requirements, Art. 106 para. 2 BGG): The Federal Supreme Court intervenes only if the cantonal solution is untenable, in manifest contradiction with the actual situation, adopted without objective grounds or in violation of a clear right (ATF 141 I 172 consid. 4.3.1). As regards the 18-month time limit of Art. 7 para. 4 LPMNS, the cantonal court did not rule formally but implicitly dismissed the complaint, which suffices in light of the right to be heard (ATF 143 III 65 consid. 5.2). On the merits, the exceeding of the time limit is established, but the only consequence provided by the law and cantonal case law is the possibility of an appeal for formal denial of justice; it does not prevent the continuation of the procedure, whose objective was achieved since a decision was rendered. The complaint is dismissed. As for the opinion of the CMNS (Art. 47 para. 1 LPMNS), neither the law nor its regulation imposes any minimum form or content;…