Setting the market rent without exposing yourself
Set it too low and you lose money for years. Set it too high and you get a long vacancy, or a challenge to the initial rent. The same preparation avoids both.
Compare with properties, not with hopes
A defensible comparison rests on flats in the same commune or district, with comparable room count, floor area, year of construction, fit-out and location. Net rent is what counts; comparing gross rents really means comparing service-charge models. Five carefully chosen comparables tell you more than twenty superficial ones.
Price the vacancy into the sum
A hundred francs more each month comes to CHF 1,200 a year. A single month of vacancy at CHF 2,400 costs twice that. So the question is not what the highest achievable price is, but what price reliably lets the flat inside a month.
In cantons with a mandatory form you must give the initial rent on that form and state the previous rent. A marked increase over the outgoing tenant is lawful, but it needs a reason behind it, such as a value-enhancing renovation.
These articles set out Swiss law in general terms and are not a substitute for legal advice on an individual case. Cantonal rules differ. In a dispute, contact the rent conciliation authority or a lawyer.