Your landlord must keep the flat in a usable condition. If it has a defect that significantly affects its use, your rent is reduced automatically by law (Mietminderung). You do not need the landlord's consent.
In practice, the key questions are how much the rent is reduced and how to do it without risking your lease.
What Counts as a Defect?
A defect is a deviation from the agreed or usual condition that affects use, for example:
- heating failure in winter,
- no hot water,
- mould not caused by the tenant,
- leaking roof or water damage,
- construction noise from a neighbouring site,
- broken lift in a high-rise building,
- significantly smaller floor area than agreed, by more than ten percent.
Minor impairments do not justify a reduction. Defects you caused yourself, or knew about when you signed, do not count.
How Much?
There is no fixed table. Courts decide case by case. Typical ranges from case law:
| Defect | Typical reduction |
|---|---|
| Complete heating failure in winter | 50 to 100 percent |
| No hot water | 10 to 20 percent |
| Mould in living rooms | 10 to 80 percent, depending on extent |
| Construction noise | 10 to 30 percent |
| Broken lift (upper floors) | 5 to 15 percent |
The reduction is calculated on the warm rent, including service charge advances.
How to Proceed
- Report the defect to the landlord in writing, with photos and the date.
- Set a deadline for the repair.
- Reduce the rent from the time of your report, or pay the full rent "under reservation" and reclaim the excess later.
- Document the defect and its duration.
Paying under reservation protects you against arrears if the reduction turns out too high.
Risks
If you reduce too much, you may fall into arrears. If the arrears reach a certain level, the landlord can terminate the lease without notice. Be cautious with large reductions and get advice from a tenants' association.
Other Rights
- Retention. You can also withhold part of the rent to put pressure on the landlord to repair, which you must pay once the defect is fixed.
- Self-help. If the landlord does not repair despite a deadline, you can have the defect repaired and claim the costs.
- Damages. For damage caused by the defect, for example to furniture.
- Termination. In serious cases, you can terminate the lease without notice.
Frequently Asked Questions
Can I reduce the rent for mould?
Yes, if it is not caused by your ventilation or heating behaviour. Disputes about the cause are common, so document how you ventilate and heat.
Do I have to let the landlord in for repairs?
Yes, after reasonable notice.
Can I reduce the rent retroactively?
Only from the time you reported the defect.
