If the heating fails in winter, damp appears in a wall or building noise disrupts daily life, the question quickly becomes whether you may reduce the rent. In a shared flat this often leads to disputes, because several people are affected and react differently. This guide explains the legal consequence of a rent reduction (Mietminderung) and shows how to apply it in a way that can be documented and does not escalate.
Short answer: If the flat is no longer fully fit for its agreed use, you are released from rent for that period or must pay only a fairly reduced rent (§ 536 para. 1 BGB, as of November 2026). The law sets no fixed percentage. The amount depends on the individual case. In a shared flat it pays to report defects early and in writing.
The most important points at a glance
- A defect exists if the flat is no longer fit, or only partly fit, for the agreed use (§ 536 para. 1 BGB).
- For a period of complete loss of use, you are released from paying rent.
- In the case of a reduction, you pay only a fairly reduced rent for that period.
- The law sets no fixed percentage. Each case is judged on its facts.
- Document the defect in writing, with the date, a description and photos.
When is there a defect?
A defect exists if the rented property has a fault at the time of handover or during the tenancy that removes or reduces its fitness for the agreed use (§ 536 para. 1 sentence 1 BGB). Typical examples are a heating failure in winter, damp or mould in walls, or a defective hot water boiler. In every case what matters is whether your use of the flat is actually restricted.
Not every nuisance is a defect. How mould develops and which duties you have when airing and heating is explained in the German guide Schimmel in der WG: Was Mieter tun dürfen und was nicht (in German). This article covers the legal consequence instead, that is, what happens to the rent.
What happens to the rent?
The law distinguishes two situations. If fitness for use is completely removed, you are released from rent for that period. If it is only reduced, you pay a fairly reduced rent for the affected period (§ 536 para. 1 BGB).
| Situation | Legal consequence under § 536 para. 1 BGB |
|---|---|
| Fitness for use is completely removed | You are released from rent for that period. |
| Fitness for use is reduced | You pay only a fairly reduced rent for that period. |
The release and the reduction apply to the period in which the defect exists. Once it is fixed, you owe the full rent again. That is why the duration matters as much as the type of defect.
How do you calculate the reduction in a shared flat?
The law sets no fixed percentage. The fair reduction depends on the kind, extent and duration of the defect. For an example we assume a reduction that is not a benchmark.
Assumption: the room costs 500 euros including service charges, and fitness for use is clearly reduced for two months. An assumed reduction of 20 percent gives 400 euros a month, which is 100 euros less each month. Over two months that is 200 euros. Whether 20 percent is appropriate in a specific case remains an individual question.
- Establish the agreed rent, for your share or for the room.
- Determine the period in which the defect existed.
- Estimate the impairment and explain it to the landlord.
- For larger amounts, get advice before you reduce the payment.
What to watch for in a shared flat
In a shared flat you often have a joint tenancy agreement with several people. Defects affect every resident, but the reactions differ. Agree who reports the defect, who handles the correspondence and how the reduced rent is shared among the flatmates.
A unilateral reduction without agreement quickly leads to conflict, even when the defect is real. Anyone who reduces rent without being able to prove the defect also risks falling into arrears. Raise the defect early and record what was agreed.
How do you report a defect properly?
Report the defect in writing, describe it precisely and note the date on which you noticed it. Add photos and set the landlord a reasonable deadline to fix it. Also record when you experienced the impairment, for example cold rooms or an unusable bathroom.
If you do not report it, you later lack proof of the timing and extent. That matters most when the landlord disputes that the defect existed at all. A record with photos and dates is then very valuable.
Frequently asked questions
May I simply reduce the rent if something bothers me?
No. A reduction requires a defect that actually impairs the fitness of the flat. Anyone who reduces without reason does not pay the difference to the full rent and falls into arrears. The law looks at the restriction of use in fact.
How large may the reduction be?
§ 536 BGB sets no fixed upper limit. The fair reduction depends on the kind, duration and extent of the defect. If you are unsure, a tenants’ association or a lawyer can advise you before you change the payment.
Do I have to report the defect to the landlord first?
A written defect notice is sensible, because it lets you prove timing and extent. Whether and how much time the landlord needs to fix it depends on the individual case. Do not wait too long before reporting.
Does the reduction also apply to minor defects?
A reduction requires that the defect actually removes or reduces fitness for use. A small scratch on a door is generally not enough. Whether a defect is significant enough is a question for each case.
What happens once the defect is fixed?
The reduction ends when the defect is removed. From that point you owe the full rent again. Check your transfers carefully so that you pay neither too much nor too little.
What to do now
- Document the defect with the date and photos.
- Report it to the landlord in writing and set a reasonable deadline.
- Agree with your flatmates before you reduce the rent.
- If you are unsure, get advice before you change the payment.
Related guides
- Student Housing in Germany: Rent, Shared Flats, Halls and Housing Benefit
- Mold in a Shared Flat: What Tenants in Germany May and May Not Do
- Heating Costs in a Shared Flat in Germany: Who Pays What
- Checking a German Service Charge Statement: Deadlines and Errors
- Can My Landlord Do That? Common Questions from Students
- Kündigungsfrist im WG-Zimmer: Wann du ausziehen kannst
Sources: § 536 BGB, rent reduction for material and legal defects (German) (as of November 2026).
Last updated: November 2026. This guide is general information, not individual advice.
