Tenant Evidence: Collect Comparable Flats in Germany

As a tenant in Germany, you may need to collect comparable flats when challenging a high rent, rent increase, or surcharge. This practical guide explains which data and documents help — such as listings, tenancy agreements, utility statements and photos — and how to document them systematically. I describe practical steps to select suitable comparables, record rent levels and prepare objections or court submissions to the local court. The aim is to give you simple, legally sound methods so you can better review claims and, if necessary, initiate legal steps with solid evidence. I explain how to choose comparables, watch deadlines and which official laws and courts are relevant. At the end you will find a short how-to and official links to legal texts and court information.

Why comparable flats matter

Comparable flats help show whether a rent is market-based or excessive. Relevant legal bases are found in the German Civil Code (BGB) on landlord and tenant duties and rent reduction^[1], and in the Code of Civil Procedure (ZPO) for court proceedings if a lawsuit is necessary^[2]. Documents create transparency and reduce disputes before the local court.

Which documents to collect

• Listings and online offers: copy text, price, date and link.
• Tenancy agreements: photograph or scan pages showing term, rent and agreements.
• Utility statements: secure year, billing period and line items.
• Photos of condition: dated room shots, faults (mold, heating) with timestamps.
• Timestamps and communication: date and save emails, SMS, letters.

How to select comparables systematically

Choose properties that match size, location, construction year and amenities of your flat. Pay attention to whether heating costs are included or billed separately, as this affects comparability. Note rent, area and any additional costs clearly.

• Equal area: same square meters or a clear rent/m² calculation.
• Same location: same district or comparable micro-location (e.g., public transport proximity).
• Amenities compared: balcony, fitted kitchen, energy standard.

Securing evidence and possible legal steps

Once you have collected comparables, you can request an explanation or correction of the rent in writing from the landlord. Formal steps require observing deadlines and proper form; proceedings before the local court are governed by the ZPO^[2]. It can be helpful to hand files to a legal advice center if necessary.

• Written request to landlord: set a deadline, attach evidence.
• Claim at the local court: file suit and submit exhibits.
• Seek advice: tenant association, lawyer or consumer advice early.

FAQ

Which documents matter most in court?

The most important items are comparable listings with dates, your tenancy agreement, utility statements and photos of the condition. Legal bases for tenancy are in the BGB^[1].

How long should I keep documents?

Keep documents at least until any legal dispute is finished; limitation and procedural deadlines may vary and depend on the ZPO^[2].

Where do I file a claim?

Rent disputes are usually heard first at the competent local court; appeals go to the regional court and possibly the Federal Court of Justice (BGH)^[3].

How-To

1. Search online and in newspapers for comparable offers in the same location and size.
2. Save screenshots or PDFs with date and link for each listing.
3. Photograph your flat's condition and document any defects in writing.
4. Record rent with or without utilities and calculate rent per m².
5. Write a short justification for your request, attach evidence and set a reply deadline.
6. If no agreement is reached, submit the collected documents to the local court or obtain legal representation.

Help and Support

• [1] BGB §§535–580a — gesetze-im-internet.de
• [2] Federal Ministry of Justice — bmj.de
• [3] Federal Court of Justice — bundesgerichtshof.de

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1. [1] BGB §§535–580a — gesetze-im-internet.de
2. [2] ZPO — gesetze-im-internet.de
3. [3] Bundesgerichtshof — bundesgerichtshof.de
4. [4] Bundesministerium der Justiz — bmj.de