Facts
The Vorsorgestiftung X. rented two apartments to B. and N. with rental contracts concluded on 5 February 1985 and 20 January 1987, respectively. The initial rents were 1'267 CHF and 1'300 CHF per month, respectively. The rental contracts contained no reservations regarding the rents. The Vorsorgestiftung X. increased the rents several times, citing insufficient gross yield and adaptation to expenses. The tenants contested these increases, but the Vorsorgestiftung X. asked the court to find that the new rents were not abusive.
The court rejected the Vorsorgestiftung X.'s request, considering that the rent increase was not justified due to the absence of a clear and quantitative reservation concerning the insufficient gross yield. The Vorsorgestiftung X. appealed, but the federal court rejected its appeal.
Considerations
The federal court considered that the Rent Law (art. 269a let. c CO) allows owners to request a rent increase if the gross yield is insufficient, but that this requires a clear and quantitative reservation. In the absence of such a reservation, the owner cannot invoke art. 269a let. c CO to justify a rent increase.
The court also considered that the notion of gross yield is related to the mortgage interest rate and that changes in this rate may have implications for determining the gross yield. However, the court rejected the Vorsorgestiftung X.'s…