Building permit annulled: parcel not largely built-up in provisional building zone (art. 36 para. 3 SPA), old 1952 zoning plan

Facts

The Commune of Vevey owns parcel No. 1173, located at chemin des Crosets in the locality known as "Stade de Copet", with an area of 32'761 m2, in a low-danger zone on the right bank of the Veveyse. It includes a few buildings (changing rooms, a refreshment stand, a temple, totalling 1'117 m2), an athletics track and two football pitches. Under the communal zoning plan and the 1952 regulations (updated in 1964), it is classified as zone IV "industry".

By decision of 21 August 2014, the Municipality of Vevey issued a planning permit for a college (Gilamont college) for approximately 800 pupils and 120 teachers, bordering the Veveyse. On 18 December 2014, it issued the building permit. By judgment of 1 July 2016, the Administrative Law and Public Law Chamber of the Vaud Cantonal Court (CDAP) upheld the appeals of the objectors, noting in particular an incomplete file on flood risks, non-compliance with the requirement for non-habitable basements, and a lack of coordination within the meaning of art. 25a SPA.

On 5 December 2017, the Municipality issued a new building permit subject to conditions, together with a permit for 30 parking spaces. By judgment of 14 March 2019, the CDAP dismissed the appeal of the PPE [A.] and co-appellants. It held that the perimeter was essentially built-up within the meaning of art. 36 para. 3 SPA, that the project complied with the industrial zone, and that it was a densely built-up zone within the meaning of art. 41a para. WPO allowing construction at less than 20 m (but at least 5 m) from the watercourse, with an exemption from the Directorate General for the Environment (DGE).

The appellants (PPE [A.] and seven co-owners, represented by counsel) request the annulment of the cantonal judgment and of the building permit. The City of Vevey requests dismissal. The Federal Office for Spatial Development (ARE) disputes that the parcel is largely built-up and calls for updated planning. The Federal Office for the Environment (FOEN) disputes that the area is densely built-up within the meaning of art. 41c para. 1 WPO, while considering flood protection sufficient. The Fire Insurance Establishment (ECA) defers to the court.

Main question: could the parcel be classified as largely built-up land within the meaning of art. 36 para. 3 SPA, and could the old 1952 zoning plan serve as a basis for such classification, given that the question of building density under the WPO and flood protection measures was secondary.

Considerations

As to admissibility, the Federal Supreme Court holds that the public law appeal is open (art. 82 let. a, 86 para. 1 let. d, 90 FSCA). The appellants, residing near the project and directly affected, have standing to appeal (art. 89 para. 1 FSCA). They may also challenge the considerations of the interlocutory judgment of 1 July 2016, which was not subject to direct appeal (art. 93 para. 1 and 3 FSCA).

The Federal Supreme Court recalls that building zones comprise land already largely built-up or required for construction within fifteen years (art. 15 SPA). Plans adopted before the SPA remain valid until 1 January 1988 (art. 35 para. 3 SPA). Thereafter, in the absence of a new plan delimiting building zones, the part of the agglomeration already largely built-up is deemed a provisional building zone (art. 36 para. 3 SPA). A plan established under the SPA benefits from a presumption of conformity, which is lacking for plans not adapted to the SPA (art. 21 para. 1 SPA; ATF 127 I 103; ATF 120 Ia 227).

In this case, the communal plan dates from 1952 and its amendment of 1964, well before the SPA, concerns only accessory points. The Federal Supreme Court adopts the reasoning of judgment 1C_632/2020 concerning Montreux, which applies a fortiori to Vevey, whose plan is older still and has not complied with superior law for more than thirty years. No presumption of conformity therefore exists, and only the largely built-up parts may be deemed provisional building zones under art. 36 para. 3 SPA.

The notion of land already largely built-up is interpreted narrowly (ATF 132 II 218). It presupposes a coherent built environment having the characteristics of an agglomeration, assessed according to quantitative and qualitative criteria. An unbuilt area playing its own role, in…