Mietpreisbremse: the Cap, the Exemptions, and What You Must Disclose
Tenancy law and the owners association · Stand: 2026-08-10
In a designated tight market, §556d BGB caps the rent at the start of a new tenancy at 10% above the ortsübliche Vergleichsmiete (local comparable rent). The federal enabling power was extended in June 2025 and now runs to 31 December 2029.
Bonn is covered. The Mieterschutzverordnung NRW in force since 1 March 2025 expanded coverage from 18 to 57 municipalities, Bonn among them. Its Mietpreisbremse element was extended to 31 December 2029; the other two elements (see the rent-increase and termination articles) run to 28 February 2030.
The four exemptions
| Route | Rule |
|---|---|
| Neubau (§556f s.1) | Flat first used and let after 1 Oct 2014 – permanently exempt |
| Umfassende Modernisierung (§556f s.2) | Only the first letting afterwards. BGH (VIII ZR 369/18) demands roughly one third of comparable new-build cost and genuine new-build-like improvement across several essentials (heating, sanitary, windows, floors, electrics, insulation) |
| Vormiete (§556e(1)) | If the lawful previous rent was higher, you may keep it. Increases agreed with the outgoing tenant in their final year are ignored |
| Modernisierung in the last 3 years (§556e(2)) | Add what a §559 increase would have produced |
The disclosure duty is where landlords lose. §556g(1a) BGB requires you to tell the tenant, unaufgefordert (unprompted) and in Textform, before they sign, which exemption you are using and the underlying figure. Skip it and you simply cannot rely on the exemption. Provide it late in correct form and you may only rely on it two years later.
If the rent was too high, the tenant must rügen (object). Under §556g(2), an objection within 30 months of the tenancy starting, while it is still running, reclaims overpayments back to day one; later, only from the objection onwards.
Note: a further reform ("Mietrecht II") had its first Bundestag reading on 10 July 2026 and is not yet law.
Verified Primary Sources:
- §BGB §556d – Zulässige Miethöhe bei Mietbeginn(Bundesministerium der Justiz / juris, 2026-08)
- §BGB §556g – Auskunftspflicht und Rüge(Bundesministerium der Justiz / juris, 2026-08)
- §Mietpreisbremse und Kappungsgrenze in Nordrhein-Westfalen(Haufe, 2026-08)
- §Verlängerung der Mietpreisbremse in NRW bis 31.12.2029(Kommunen.NRW / Städte- und Gemeindebund NRW, 2026-08)