Termination, rent adjustment, ancillary costs, defects: the key points of Swiss tenancy law compactly summarised.
The rental contract for residential and business premises is governed by Art. 253 et seq. CO. Tenancy law is mandatorily tenant-friendly — clauses deviating from the contract to the detriment of the tenant are in most cases invalid. This makes Swiss tenancy law one of the most tenant-friendly in Europe.
Contract conclusion and rental deposit
Rental contracts are valid without any form requirement — written form is customary but not required. A rental deposit may not exceed three months' rent (Art. 257e CO) and must be deposited in a blocked bank account in the tenant's name. Upon move-out it is released after balance clarification — usually within 30 days.
Termination
Written form is mandatory (Art. 266l CO), with the use of the official form for residential contracts. A termination without the official form is void.
Notice periods: for apartments 3 months, for furnished single rooms 2 weeks, for business premises 6 months, in each case to a locally customary date (in most cantons end of March, June, September; for business premises often quarter-end).
Landlord terminations can be contested for abusiveness (Art. 271 CO) — for instance when the landlord terminates after a justified defect complaint by the tenant, or without recognisable material reason. The contestation period is 30 days; conciliation proceedings are mandatory.
Rent adjustment
Adjustments are tied to the mortgage reference interest rate and to general inflation. An increase must be notified formally on the official form with reasons and a ten-day deadline for contestation — otherwise invalid.
Tenants have a claim to rent reduction when the reference interest rate decreases. This claim lapses if not asserted — so actively check and request in writing when conditions permit.
Ancillary costs
Only the ancillary costs explicitly listed in the contract are owed (Art. 257b CO) — heating, hot water, building service, water/sewage, lift. General 'flat rates' are critical and as a rule contestable. The tenant has the right to inspect a detailed annual statement of ancillary costs — with receipts, not just the balance.
Defects and remedies
In case of defects (defective heating, mould, noise, missing items), the tenant must report the defect immediately. The landlord has a reasonable period for remediation. If it elapses unsuccessfully, the tenant is entitled to a rent reduction (Art. 259d CO), damages, or in case of serious defects extraordinary termination.
The rent reduction is measured by the impairment of use value — a broken heater in winter can justify a 20-30% reduction, persistent mould up to 50%.
Move-out and return
Upon move-out, a handover protocol is jointly prepared. The tenant is liable for damage not caused by normal wear and tear — scratches on wooden floors yes, faded wallpaper no. Disputed points are negotiated before the conciliation authority; a direct reduction of the deposit by the landlord is not permitted.