Mietminderung: Your Rights as a Tenant in Germany (2026)

What is a Mietminderung?

The Mietminderung (rent reduction for a defect) is your statutory right to pay less rent for as long as your flat has a defect that more than insignificantly impairs its fitness for use (§ 536 BGB). Crucially, the reduction takes effect automatically by force of law — as soon as the defect exists, the rent you owe for that period is reduced by operation of law. You do not have to apply for it from the landlord or in court.

A defect (Mangel) is any condition that impairs the agreed use of the flat — such as mould, a broken heating system, persistent construction noise, leaking windows or damp. Trivial issues (a small scratch, a briefly dripping tap) are not enough.

The condition: you must report the defect (§ 536c BGB)

However automatically the reduction applies in law, in practice everything hinges on the Mangelanzeige (defect notice). Under § 536c BGB you must report any defect to the landlord without delay and give them the chance to fix it. If you skip this notice, you can lose your reduction right entirely.

So always report the defect in writing and in a way you can prove (ideally with a photo and a deadline to fix it). The date of the notice is also the point from which your reduction is cleanly documented if there is a dispute.

Important: Do not just cut the rent on your own. Until the correct Minderungsquote is settled, keep paying the full rent under Vorbehalt (reservation) and reclaim the reduced portion. A tenant who reduces too much and falls into payment arrears risks a Kündigung (§ 543 BGB) — which can mean losing the flat.

Step by step

1. Document the defect — photos, videos, the date, the rooms affected; for mould or noise keep a short log (when, how severe).
2. Send the Mangelanzeige — in writing to the landlord, with a description and a reasonable deadline to fix it (§ 536c BGB).
3. Estimate the rate — how severe is the impairment. Anchor it to comparable court decisions, not to a number you hope for.
4. Pay under Vorbehalt — keep paying the full rent and state in writing that you reclaim the reduced amount.
5. Settle once it is fixed — the reduction applies only to the period the defect existed; after that the full rent is due again.

What Minderungsquote is typical?

There is no statutory table. The amount depends on the severity and duration of the impairment (§ 536 BGB) and is judged case by case. The figures below come from published court decisions and are only reference points — they can vary considerably by court, region and the individual case.

Defect	Court-typical rate*
Heating failure in winter	20–70 % (up to 100 % if the flat is uninhabitable)
Mould (bathroom/bedroom)	approx. 30 %
Persistent construction or neighbour noise	approx. 20 %
Hot-water failure	depending on extent, mid-range
Leaking windows / draughts	low single digits to mid-range

*Reference points from case law, not a guarantee. When in doubt, have it checked by a lawyer or a Mieterverein (tenants' association).

Common mistakes

• Cutting the rent on your own without notice — without a Mangelanzeige (§ 536c BGB) the reduction is open to challenge.
• Reducing without Vorbehalt — payment arrears and Kündigung risk (§ 543 BGB).
• Setting the rate too high — reduce more than is justified and you pay the difference and fall into arrears.
• Self-caused defects — no reduction for damage you caused or already knew about at move-in (§ 536b BGB).
• Not documenting the defect — without photos and dates you can prove nothing in a dispute.

With HausMaus it's simpler

HausMaus has a free Mietminderung calculator: you select the defect and the app estimates a Minderungsquote anchored to case law for your rent. HausMaus then generates the matching Mangelanzeige to the landlord, so you assert your right under § 536 BGB correctly — including the reminder to document the defect first and to pay under Vorbehalt. For tenants this is free.