Trèfle-Blanc the 400 million euro project gets underway

The major Trèfle-Blanc project in Geneva, which is one of the most ambitious projects in the region with an investment volume of CHF 400 million, is taking shape. After initial confusion about the exact costs, the government is now presenting a transparent investment law that breaks down the financing in detail and paves the way for realisation

July 2025

The question of the actual costs of the Trèfle Blanc project caused speculation in the run-up to the project. Estimates ranged from 275 to 400 million francs. Now the Geneva government is providing clarity with the submission of a comprehensive investment bill. The initial discrepancy is not the result of a change of plan or “salami-slicing”, but of the detailed breakdown of the various funding sources and project phases.

Initially, a credit of CHF 275.5 million will be submitted to the Grand Council for approval. This sum primarily covers the construction of two ice rinks (232 million), supplemented by costs for outdoor facilities (7.9 million), the tram connection (over 9 million), contingencies (9.3 million) and inflation (8.3 million). If this loan is approved by parliament, it could still be subject to a referendum if necessary.

However, this sum does not represent the total costs for the canton, as CHF 17 million has already been spent on preliminary studies. This means that the total costs borne by the state to date already amount to CHF 293 million.

Why it is 400 million
The confusion surrounding the CHF 400 million is cleared up when the park-and-ride car park is included. This car park, whose construction will begin before the rest of the infrastructure, will provide 928 parking spaces for cars and 244 for motorbikes. It will cost an estimated CHF 99 million, a sum that is not directly requested by parliament. It will be financed by the Car Park Foundation, an autonomous public-law institution, which will borrow 75 million francs with the approval of the state, while the rest will come from its own funds. The repayment of this loan is secured in the long term by the income from the P R.

The financing architecture
It is essential to add this CHF 99 million to the total cost of the Trèfle Blanc project. Regardless of the source of financing used, this is public money, as the car park foundation is part of the public sector, similar to the Geneva utilities or the Geneva University Hospitals. This can also be seen in the consolidated financial statements of the Canton of Geneva. As the Presidential Department of the State Council confirms, everything is interconnected. A successful referendum against the 275 million loan would bring the entire project, including the P R, to a halt.

The transparency in the cost breakdown of the Trèfle-Blanc project now creates the basis for an informed debate and paves the way for the realisation of this important infrastructure project, which will have a significant impact on Geneva.

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