Rent Increase Rules in Baden-Württemberg: Rent Brake and Cap

Adjusting an existing rent in Germany is subject to strict procedural requirements and substantive limits. Landlords in Baden-Württemberg must pay special attention to the state's Tenant Protection Ordinance (Mieterschutzverordnung), which lowers the standard rent cap in tight housing markets.

Disclaimer: This guide provides general legal information for educational purposes only and does not constitute legal advice. Always consult a licensed attorney in Baden-Württemberg for guidance specific to your situation. Information last verified: March 2026.

Increase to Local Comparable Rent (§ 558 BGB)

The most common method for raising rent in an open-ended residential lease is an adjustment to the local comparable rent (ortsübliche Vergleichsmiete).

Requirements:

1. Consent procedure: The landlord must request the tenant's consent to the increase in writing (Textform — letter or email) and provide justification.
2. Justification methods: The landlord may reference the municipality's official rent index (Mietspiegel), an expert appraisal by a sworn appraiser, or three comparable properties.
3. Waiting period: The rent must have remained unchanged for at least 15 months before the increase becomes effective. The increase request itself may not be sent earlier than 12 months after the last increase.

Tenant's Consideration Period

After receiving the increase request, the tenant has the remainder of the month it was received plus the following two full months to review and respond. If the tenant does not consent, the landlord has an additional three months to sue for consent.

The Rent Cap (Kappungsgrenze) in Baden-Württemberg

In addition to the requirement that rent cannot exceed the local comparable rent, the rent cap acts as a further ceiling.

Under federal law (§ 558 BGB), the base rent may not increase by more than 20% within any three-year period.

Baden-Württemberg's special rule: In designated tight housing markets, the state government has reduced the cap to 15%. The Tenant Protection Ordinance was renewed on December 16, 2025, extending the reduced 15% cap through December 31, 2026, now covering 130 cities and municipalities. Always check whether your property's municipality is listed in the ordinance (including Stuttgart, Freiburg, Karlsruhe, Ulm, Heidelberg, Mannheim, and many others).

Example: If your net cold rent is €1,000, you may raise it to no more than €1,150 within three years under the reduced cap — provided this does not exceed the local comparable rent.

Modernization Surcharge

If an energy-efficient renovation, window replacement, or other qualifying modernization (§ 555b BGB) has been carried out, different rules apply.

Under § 559 BGB, the landlord may increase the annual rent by 8% of the modernization costs attributable to the unit. Pure maintenance or repair costs must be deducted first. Additional ceilings apply: generally, rent may not increase by more than €3 per square meter within six years due to modernization (or €2/sqm if the base rent is below €7/sqm). Modernization surcharges are exempt from the rent cap.

Index and Graduated Rent

To avoid the burden of repeatedly proving the local comparable rent, many landlords opt for an index rent or graduated rent from the outset:

• Index rent (§ 557b BGB): The rent is tied to the Consumer Price Index (CPI/Verbraucherpreisindex) published by the Federal Statistical Office. When the index rises, the landlord may increase the rent proportionally after providing written notice. The standard rent cap does not apply to index rent increases.
• Graduated rent (§ 557a BGB): At the time of contract signing, the parties fix the exact amounts and dates of future rent increases in writing (e.g., €30 increase every January 1). There must be at least one year between steps.

Note: In municipalities where the rent brake applies, the initial graduated rent level is also subject to rent-brake limits.

Simplifying Increases with Landager

The rent increase procedure is highly error-prone under German law — a formally defective request is legally void, costing the landlord time and revenue. Landager alerts you when the 15-month waiting period expires, checks the local rent cap based on your property's postal code, and generates legally compliant consent request letters automatically.

Back to Baden-Württemberg Landlord-Tenant Laws Overview.