When the reference interest rate (web page available in German, French and Italian) is lowered. It is currently at 1.75%;
If your rent is based on a higher interest rate than the current reference rate;
Under certain circumstances, you can request a review within 30 days of moving into your flat, for example, if you find out that you are paying at least 10% more than the previous tenant;
If the use of your apartment is impaired due to a defect, including, for example, a malfunctioning oven, room temperature that is too low, construction work in the building and noise issues.