Tenant: Documenting Window Replacements in Germany

Modernization & Cost Allocation 2 min read · published September 07, 2025

As a tenant in Germany, you should carefully document a window replacement, especially when modernization measures or cost allocation are involved. This guide explains in clear terms which evidence to collect, how to handle deadlines and written notices, and when to involve authorities or the local court. We show concrete examples for photo documentation, protocols during inspections and template letters to the landlord. The goal is to protect your rights in rent reduction, objection to modernization notices or disputes over charges. Use the steps here to present clear evidence later if a dispute arises.

Why precise documentation matters

A clean record helps determine whether the work is modernization or maintenance, which costs may be charged to you, and whether impairments such as heat loss occurred. Legal bases can be found in the Bürgerliches Gesetzbuch (BGB)[1] and, for procedural questions, in the Zivilprozessordnung (ZPO)[2].

Detailed documentation increases your chances of success in disputes.

Before the measure: check and secure

  • Check the landlord's notice period and note the date of the notification.
  • Request a written modernization notice with a cost breakdown and save the document.
  • Take baseline photos of the windows, frames and the interior side of the apartment with dates.
Ask for a joint handover protocol during handover or inspection.

Example: Wording for a request to the landlord

Send a short email or letter requesting the following information: start and end dates, contractor name, scope of work, expected impairments and who bears the costs. Keep proof of sending.

During the replacement: document regularly

  • Photograph the work daily, especially conditions before and after installation.
  • Record agreed access times and any handover of keys.
  • Keep a communication log with dates, names and summaries of conversations.
Keep all receipts and photos organized so they can be retrieved easily.

After the measure: inspect, complain, consider legal action

Compare the performed work with the notice: were promised functions (e.g., tightness, soundproofing, thermal protection) delivered? If defects exist, document them in writing and demand a deadline for remediation. If cost allocation is unclear, check whether costs are modernization costs under the BGB or maintenance costs that the landlord may not charge to you[1].

Local courts (Amtsgerichte) handle many tenancy disputes.

FAQ

Who pays for the window replacement — landlord or tenant?
In principle the landlord bears the costs; allocation is only possible for modernization measures and under certain conditions.
Can I reduce rent because of dust or noise?
Yes, significant impairments can justify rent reduction; document duration and extent of disturbance carefully.
When should I contact the local court?
If out-of-court resolution fails or deadlines are missed, filing a claim at the local court might be considered; observe ZPO rules[2].

How-To

  1. Request the written modernization notice and note the date of receipt.
  2. Create an evidence folder: photos before/after, date stamps, witnesses, written communications.
  3. Set deadlines for defect remediation and send written reminders if dates are missed.
  4. Seek legal advice or contact the competent local court if objection or litigation is necessary.
Keep a copy of all photos and letters permanently.

Help and Support


  1. [1] Gesetze im Internet – BGB
  2. [2] Gesetze im Internet – ZPO
  3. [3] Bundesgerichtshof (BGH)
Bob Jones
Bob Jones

Editor & Researcher, Tenant Rights Germany

Bob writes and reviews tenant law content for various regions. They’re passionate about housing justice and simplifying legal protections for tenants everywhere.