OFL reference rate and rent reduction
In Switzerland, much residential rent follows the mortgage reference rate published by the pension fund federation (OFL/BWO) and the Swiss consumer price index (CPI). When these move in the tenant’s favour, Art. 270a of the Code of Obligations may allow a reduction request — subject to conditions and deadlines.
What is the OFL reference rate?
The reference rate (mortgage reference interest rate) is set periodically by the Swiss pension fund federation (OFL), on behalf of the Federal Office for Housing (BWO). It reflects average mortgage financing costs in Switzerland.
It is not your personal loan rate: it is a national benchmark used to adjust rent when the lease or law refers to it. Official published values underpin the calculation under the ordinance on tenancy law (OBLF), especially Art. 13.
How the rate and CPI affect net rent
For leases under Swiss law, the usual formula combines how the reference rate changed between the rent fixation date and today with CPI movement over the same period — in practice only 40 % of CPI counts (Art. 13 OBLF).
Only net rent (excluding recoverable charges and ancillary costs) matters. A higher reference rate may justify an increase; a lower one may, if other conditions are met, support a reduction.
When to request a reduction (Art. 270a CO)
Art. 270a CO lets a tenant request a reduction when the reference rate has fallen or CPI has dropped since the last rent fixation and current net rent exceeds the theoretical rent under the legal method.
The request must reach the landlord at least three months before the next annual due date (or the next contractual adjustment date). Refusal or prolonged silence may lead to the cantonal conciliation board — the usual step before court.
What Swirent does — and its limits
Swirent compares your net rent to official indices and estimates theoretical rent under Art. 13 OBLF. You receive draft letters to adapt and send yourself; we do not file proceedings on your behalf and guarantee no outcome with landlord or authority.
Each case depends on contract, canton and facts (initial rent, charges, works, etc.). When in doubt, qualified legal advice is advisable.