Facts
The dispute concerns the method of calculating rent indexation upon the tacit renewal of a lease containing an indexation clause.
In 2004, the lessor rented an apartment to the tenants for an initial period of 5 years, with a clause for tacit renewal in 5-year periods. The contract provided for rent indexation based on the evolution of the Swiss consumer price index.
Upon the tacit renewal of the lease in 2009, the lessor notified a rent increase based on the evolution of the index between 2007 and 2009. The tenants objected to this increase, considering that it should have been calculated based on the index of February 2009, the date of the tacit renewal.
The cantonal courts ruled in favor of the lessor, considering that the indexation should be calculated from the last rent setting, without taking into account the tacit renewal.
The tenants appealed to the Federal Tribunal, which dismissed their appeal.
Considerations
The Federal Tribunal considered that when a lease with an indexation clause is tacitly renewed for a 5-year period, the next indexation must be calculated by referring to the index known at the time of the last rent setting, without regard to the tacit renewal.
Indeed, the tacit renewal marks the continuity of the contractual relationship rather than a break. The parties have expressly agreed to the indexation upon conclusion of the…