Mould (Schimmel) in a rented flat: your rights and what to do
How to report and record mould properly, and when it reduces your rent.
Mould reduces your rent automatically for as long as it lasts, unless you caused it. Report it to the landlord in writing at once, photograph it, and keep paying the full rent under Vorbehalt (reservation) until the amount and the cause are settled.
What to do about mould
The order matters. These steps protect your rights.
- 1
Report it at once
Tell the landlord about the mould in writing without delay (§ 536c BGB).
- 2
Take photos
Photograph the mould and the room around it, so that its size and position are clear.
- 3
Pay under Vorbehalt
Keep paying the full rent under Vorbehalt until the amount and the cause are settled.
- 4
The rent is reduced automatically
The rent is reduced for as long as the mould lasts, if you did not cause it.
- 5
The landlord has to explain the cause first
The landlord must first show that the cause does not come from their side.
- 6
Then you show how you heated and aired
Only then do you have to prove that you heated and aired the flat properly.
Why this matters
Under § 536c BGB, you must report damage that appears during the tenancy without delay. If you report it too late, you can lose the right to reduce the rent and be liable for follow-on damage.
General information, not legal advice.
Frequently asked questions
Do I have to report mould to the landlord?
Yes, you have to report mould to the landlord at once and in writing (§ 536c BGB). If you report it too late, you can lose the right to reduce the rent and be liable for follow-on damage.
How much can I reduce the rent for mould?
The reduction depends on how bad the mould is, how far it has spread and where it is. The law has no table. Court rulings range from about 5% for small spots in the bathroom up to 100% for massive mould that endangers health.
Can I reduce the rent even if I might have aired the flat wrongly?
Yes, you can reduce the rent as long as it is not established that you caused the mould. But only reduce under Vorbehalt, so that you do not fall into arrears (§ 543 BGB).
Also in this topic: Schönheitsreparaturen: must I renovate when moving out?Moved into an unrenovated flat? What you must proveLimitation under § 548 BGB: six months for damage, what tenants need to knowMay my landlord take photos of my flat?All guides: Rights & duties
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