Tenant Rights: Window Replacement in Germany 2025

Many tenants in Germany are faced in 2025 with a modernization notice such as a planned window replacement. As a tenant you have clear rights: the landlord must state the reasons for modernization, observe deadlines and formal requirements, and make any cost allocation transparent. This article explains in plain language which legal bases apply, which forms and evidence are useful, and when an objection makes sense. I give practical steps: how to check the notice, which documents (photos, correspondence) help, how to check cost breakdowns and when the local court is the right authority. At the end you will find a short how-to for objections and links to official statutes and courts.^[1] Read on for practical tips.

What does window replacement mean?

Window replacement is often part of a modernization. Landlords may replace windows to save energy or improve the building fabric. Important for tenants: a modernization notice must be written, justified and include a deadline; also, cost allocation is only permitted under certain conditions.

• The landlord must send a written modernization notice with reasons and a deadline.
• You can oppose a cost allocation if the work is not necessary or the costs are not explained transparently.
• If the work is poorly executed, you are entitled to warranty rights and possibly rent reduction.
• If there is a dispute about costs or the effectiveness of the modernization, the local court is responsible.

Cost allocation and modernization

When may the landlord modernize?

Modernization measures must serve the preservation or improvement of the rented property. The landlord must explain purpose and scope; for measures that increase value he may partially allocate costs to tenants. The relevant rules are found in the German Civil Code (BGB) on modernization and cost allocation.^[1]

How are costs distributed?

The cost breakdown should be comprehensible: total amount, allocable share and the calculation basis. Check quotes, invoices and whether subsidies reduce the allocable share. If the calculation is unclear, request a detailed breakdown from the landlord.

FAQ

Which deadline must the landlord observe?

The landlord must announce the modernization in good time and in writing; the exact deadline depends on the content and scope of the measure.

Can I object to the cost allocation?

Yes. Objection is possible if the measure is not a modernization, the costs are disproportionate, or there are formal errors.

Where do I file a lawsuit if there is a dispute?

For tenancy disputes, the local court (Amtsgericht) is usually competent; procedural matters are governed by the Code of Civil Procedure.^[2][3]

How-To

1. Check the notice immediately for date, scope, reasons and deadlines.
2. Request a detailed cost breakdown and check whether subsidies were taken into account.
3. Collect evidence: photos, emails, letters and invoices as proof.
4. If no agreement is possible, consider filing a lawsuit or mediation at the local court.

Help and Support / Resources

• BGB §§ 535–580a (Gesetze im Internet)
• ZPO (Code of Civil Procedure) – Gesetze im Internet
• Federal Court of Justice – Tenancy Law

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1. [1] Gesetze im Internet – BGB §§ 535–580a
2. [2] Gesetze im Internet – ZPO
3. [3] Bundesgerichtshof – Mietrecht