Challenge Comparable Flats: Tenants in Germany

As a tenant in Germany, it is often necessary to collect comparable flats to contest an unlawful rent increase or a wrong application of the rent price cap. In this article I explain step by step which evidence and wordings help, how to observe deadlines and which courts are responsible. The guidance is practical and explains which documents you should collect, how to write a formal request to the landlord and when going to the local court is advisable. At the end you will find sample texts, a short FAQ and a practical how-to so you can assert your rights as a tenant in Germany clearly and securely. I also name official sources and explain how to prepare forms or lawsuits.

Collecting comparable flats

Comparable flats are used to demonstrate the local comparative rent or to review a claimed rent increase. Relevant information and duties are found in the BGB^[1]. Collect clear, verifiable information about location, living area and features.

• Photos and floor plans of the comparable flat
• Copies of listings with rent prices and dates (e.g. property portals)
• Copies or excerpts of rental agreements showing rent amounts
• Address and contact details of the previous landlord or broker
• Comparison tables with living area, room count and equipment

When and how to contest?

You should contest as soon as you have concrete evidence or receive a formal rent increase. Set a written deadline for the landlord to explain and name the comparable flats as evidence. For court steps, the Civil Procedure Code (ZPO) applies^[2], and the local district court (Amtsgericht) is usually the first instance.

• Set a deadline: Request a statement within 14–30 days.
• Use written form: Send by registered mail or use verifiable fax/e-mail.
• Attach evidence: Include copies of listings, photos and calculations.
• Log communications: Note calls and any landlord responses.

Forms and courts

There is usually no standard official "comparable flats" form. Court actions follow the ZPO and the competent court is typically the district court at the property location^[2]. The Federal Court of Justice publishes important rental law decisions that can guide you^[3].

Practical approach: Send a formal request to the landlord with a deadline, attach your evidence, and ask for a written reply. If the landlord does not respond or the reply is insufficient, present the documents to the district court and consider a declaration or performance action.

Sample texts

Use precise wording. Example: "I hereby request that you disclose the calculation of the rent increase and name the underlying comparable flats in writing by DD.MM.YYYY. Otherwise I reserve the right to take legal action." Record the date, method of dispatch and any replies.

FAQ

What are comparable flats?

Comparable flats are similar apartments recently rented or offered in the same area that are used to determine the local comparative rent.

Which evidence is most important?

Listings with price and date, signed rental agreement copies, photos and clear comparison tables are most persuasive.

How much time do I have to respond?

Set a clear deadline for the landlord (commonly 14–30 days). Court deadlines follow the ZPO.

How-To

1. Collect evidence: listings, photos, floor plans and contract excerpts.
2. Create a comparison table with area, rooms and features.
3. Write a formal request to the landlord including a deadline and attach evidence.
4. Document all replies and calls precisely.
5. If necessary, submit the materials to the competent district court or seek legal advice.

Help and Support

• Gesetze im Internet: Bürgerliches Gesetzbuch (BGB) §§ 535 ff.
• Gesetze im Internet: Zivilprozessordnung (ZPO)
• Bundesgerichtshof: Decisions

1. [1] Bürgerliches Gesetzbuch (BGB) §§ 535–580a
2. [2] Zivilprozessordnung (ZPO)
3. [3] Federal Court of Justice (Bundesgerichtshof) - Rental Law Decisions