How to Get a Rent Reduction for a Hot Apartment in Germany (2026 Guide)

If you're renting in Germany, you already know that summers can be brutal—especially in older buildings without air conditioning. But did you know that extreme indoor heat can legally qualify as a defect (Mangel) that entitles you to a rent reduction (Mietminderung)? In 2026, with climate change pushing temperatures higher, this topic is more relevant than ever for expats. This guide explains your rights, how to document the issue, and exactly how to request a reduction from your landlord.

What Counts as a Heat-Related Defect?

German law does not specify a maximum indoor temperature, but courts have set guidelines. Generally, if the indoor temperature exceeds 26°C for prolonged periods—especially in bedrooms or living rooms—you may have grounds for a rent reduction. Key factors include: the apartment's location (top floor under a roof is worse), lack of effective sun protection (e.g., no shutters or blinds), and insufficient ventilation. The defect must be significantly impairing the usability of the apartment. For example, if you cannot sleep at night or work from home because of the heat, that strengthens your case.

Before You Request a Reduction: Document Everything

To succeed with a Mietminderung, you need solid evidence. Do the following before contacting your landlord:

• Use a calibrated thermometer to measure indoor temperature at different times of day (morning, afternoon, evening). Record the date, time, and temperature.
• Take photos or videos showing the thermometer reading, especially during peak heat hours (2–5 PM).
• Note any health issues you experience, like headaches, dizziness, or sleep problems—keep a simple log.
• Check if your apartment has adequate sun protection: blinds, awnings, or exterior shutters (Rollläden). If not, that's a defect itself.
• If you have a weather station nearby, note outdoor temperatures to show the contrast.

Tip: Use a digital max-min thermometer to prove how high temperatures climbed overnight.

How Much Can You Reduce the Rent?

The amount depends on the severity and duration of the heat. There's no fixed percentage, but German court rulings give guidance. For apartments with indoor temperatures above 30°C for several hours a day, reductions of 10–20% have been accepted. For extreme cases (e.g., 35°C+ with no sun protection), reductions up to 50% have been seen. However, be realistic: a 10% reduction for a few hot weeks is a common starting point. Always calculate based on the net rent (Kaltmiete), not including utilities (Nebenkosten).

Step-by-Step: How to Request a Rent Reduction

1. Notify your landlord in writing (email or letter) as soon as the heat becomes a problem. Describe the defect, mention you are documenting temperatures, and state that you intend to reduce the rent from the next payment onward.
2. Set a reasonable deadline (e.g., 14 days) for the landlord to fix the issue (e.g., install blinds or awnings). If they don't respond, you can proceed with the reduction.
3. Calculate the reduction and deduct it from your next rent payment. Clearly state the amount and the reason in your payment reference (Verwendungszweck). Example: "Rent for July 2026: €800 minus 10% Mietminderung due to excessive heat = €720."
4. Keep paying the reduced amount monthly until the defect is resolved. If the landlord fixes it (e.g., installs external blinds), the reduction ends.
5. If the landlord disputes, you may need to consult a tenant's association (Mieterverein) or a lawyer. Legal insurance (Rechtsschutzversicherung) can cover this.

Important: Never stop paying rent entirely—only reduce it. Withholding full rent can lead to eviction.

What If Your Landlord Refuses or Takes Legal Action?

Landlords often push back. If you receive a warning letter (Abmahnung) or are sued for unpaid rent, don't panic. German courts generally side with tenants when proper documentation exists. Join a Mieterverein (costs ~€50–100 per year) for legal advice and support. They can help you draft responses and even represent you in court. Also, consider getting a lawyer specialized in tenancy law (Mietrecht). If you have legal insurance, check if it covers rental disputes.

Practical Tips for Keeping Your Apartment Cool (Without AC)

While you pursue a rent reduction, try these proven strategies to lower indoor temperatures:

• Keep windows and blinds closed during the day, especially on the sunny side. Open them only at night or early morning when it's cooler.
• Use reflective films on windows (check your lease first—some landlords prohibit them).
• Place a bowl of ice in front of a fan for a DIY air cooler.
• If you have a balcony or garden, consider a mobile evaporative cooler—but beware of humidity issues.
• Cook outside on a grill or use a microwave instead of the oven.

These won't fix the defect, but they can make waiting for the landlord's action more bearable.

Frequently Asked Questions

Can I get a rent reduction if my apartment is on the top floor with no roof insulation?

Yes, top-floor apartments under a poorly insulated roof are particularly vulnerable. The lack of insulation can be considered a defect that impairs the use of the apartment. Document temperatures and request the landlord to improve insulation or install sun protection. Reductions of 10–20% are common in such cases.

Do I need a lawyer to request a rent reduction for heat?

No, you can do it yourself by sending a written notice with your documentation. However, if the landlord disputes or takes legal action, joining a tenant's association (Mieterverein) or hiring a lawyer specialized in tenancy law is strongly recommended. Legal insurance can help cover costs.

How long can I reduce the rent for heat issues?

You can reduce the rent for as long as the excessive heat persists and the landlord hasn't fixed the defect. Typically, this applies during the summer months (June–August). Once the temperature drops or the landlord installs sun protection, the reduction ends. You must stop reducing when the defect is resolved.

Will a rent reduction affect my relationship with the landlord?

It can strain the relationship, but your rights as a tenant are protected by law. Most landlords understand that excessive heat is a legitimate defect. To minimize conflict, always communicate politely, provide clear documentation, and offer a deadline for fixes. If the landlord responds positively, you can negotiate a compromise (e.g., partial reduction) without legal escalation.