Condo Conversion Protection in Frankfurt: Two Rules, Both Weaker Than You'd Expect Right Now
If your rental building gets converted into individually sellable condominiums, two separate protections are supposed to matter, and both are currently narrower in Frankfurt than they were designed to be. First, a permit requirement to convert at all: Hessen's citywide rule for buildings with 7 or more units expired on its own schedule on December 31, 2025, and wasn't renewed, so since January 1, 2026, a conversion permit is only required inside Frankfurt's 14 designated Milieuschutzgebiete (Bockenheim, Nordend, Sachsenhausen-Nord, Bornheim, Ostend and similar areas), under a different federal law, paragraph 172 BauGB. Outside those zones, landlords can convert freely. Second, the extended eviction protection after a conversion sale, the Kündigungssperrfrist, was set at 8 years in Frankfurt under Hessen's Mieterschutzverordnung, well above the federal 3-year default, but a June 2026 Amtsgericht Frankfurt ruling declared that whole regulation invalid, and courts are currently treating the extended period as reverted to 3 years for anything from December 2025 onward. Neither situation is Berlin's active, citywide, decade-long protection.
Two Separate Rules, Not One
Most explanations of “condo conversion protection” in Germany talk about it as if it’s a single thing. In Frankfurt right now, it genuinely isn’t, and conflating the two leads people to the wrong conclusion about their own situation. There are two independent mechanisms, with two different legal bases, two different current statuses, and neither one currently works the way Berlin’s does.
The first is a permit requirement to convert a rental building into individually sellable condominium units at all. The second is an extended eviction protection for the sitting tenant once a specific unit has actually been sold to a new owner. You can be affected by one, both, or neither, depending on your address and your building’s sale history.
Rule One: The Conversion Permit, Now Zone-Specific
Hessen introduced a citywide requirement in 2022, under the Umwandlungsgenehmigungs- und Gebietsbestimmungsverordnung, that buildings with 7 or more rental units needed a formal permit before converting to condominiums, in areas designated as tight housing markets. That citywide requirement expired on its own schedule on December 31, 2025, and Hessen didn’t renew it. This expiration is separate from the court case described below, it ran out on its own terms, not because of litigation.
Since January 1, 2026, a conversion permit in Frankfurt is only required inside the city’s designated Milieuschutzgebiete (social preservation zones), under a completely different law: paragraph 172 of the federal Baugesetzbuch (BauGB), not the expired Hessen state ordinance. Frankfurt currently has 14 such zones, identified by codes E2Ä, E4, E5, E7, E9, E43, E44, E47, E50, E51, E52, E53, E55, and E56, covering parts of Bockenheim, Nordend, Sachsenhausen-Nord, Bornheim, Ostend, and similar neighborhoods. You can check your own address against these zones through the city’s planAS.frankfurt.de planning tool.
| Period | Where a permit was required |
|---|---|
| Through December 31, 2025 | Citywide, for buildings with 7+ rental units, under Hessen's state ordinance |
| From January 1, 2026 | Only inside Frankfurt's 14 designated Milieuschutzgebiete, under federal paragraph 172 BauGB |
| Outside those 14 zones, from January 1, 2026 | No conversion permit currently required |
Even inside a protected zone, a permit isn’t automatic. According to the building authority, approval is only granted in narrow, specific exceptions: an inheritance division among heirs, a family member taking over a unit for their own occupancy, or the owner committing in writing, recorded in the property deed, to sell converted units exclusively to their existing sitting tenants for 7 years. A straightforward conversion aimed at the open market generally won’t clear that bar inside a protected zone.
Rule Two: The Extended Eviction Protection, Same Legal Limbo as the Mietpreisbremse
If you’ve read SettledIn’s page on Frankfurt’s Mietpreisbremse, the next part will look familiar. Separate from the permit question above, German federal law (paragraph 577a BGB) gives a sitting tenant protection from an owner-occupancy eviction for a set period after their unit is converted and sold to an individual buyer, a default of 3 years nationwide. States can extend that period in tight-market areas, up to a legal ceiling, and Hessen’s Mieterschutzverordnung set it at 8 years for Frankfurt and the other 48 designated municipalities.
That’s the same regulation whose November 2025 renewal the Amtsgericht Frankfurt ruled invalid on June 10, 2026, in a case that also directly addressed this extended protection. Reporting on the ruling (case Az. 33029 C 130/25) states plainly that the 8-year period reverts to the federal 3-year default as a result. The court’s reasoning was the same as in the Mietpreisbremse case: Hessen’s justification for the November 2025 renewal relied on outdated data rather than current figures.
The ruling isn’t legally final, and it’s expected to be appealed. But right now, for a unit sold from December 2025 onward, the eviction protection window a new owner has to respect is being treated as 3 years, not 8.
Photo by wal_172619 on Pixabay
- Check your address against Frankfurt's 14 Milieuschutzgebiete using planAS.frankfurt.de, this determines whether a conversion permit is required for your building at all.
- If you're inside a zone, know that permits are only granted for narrow exceptions, inheritance, family owner-occupancy, or a 7-year tenant-only sale commitment.
- If your unit has already been converted and sold, work out the sale date, this determines whether you're likely still inside an 8-year eviction-protection window or already down to the contested 3-year one.
- Get both questions checked by Mieterschutzverein Frankfurt rather than assuming either protection automatically applies, the legal picture here is genuinely in motion.
Step by Step
- Look up your building’s address at planAS.frankfurt.de to see whether it falls inside one of Frankfurt’s 14 Milieuschutzgebiete.
- If you’ve received a conversion notice, ask whether the landlord is claiming one of the narrow exceptions (inheritance, family occupancy, 7-year tenant-sale commitment), since a straightforward market conversion inside a protected zone shouldn’t be approved otherwise.
- If your unit was already sold to an individual buyer, note the exact sale date, this is what determines whether the 8-year or 3-year eviction-protection window applies.
- Don’t assume Berlin’s rules apply here. Frankfurt’s situation is structurally different and currently weaker on both fronts.
- Contact Mieterschutzverein Frankfurt am Main e.V. (069 5601057-0, info@msv-frankfurt.de) with your specific address and dates before making any decisions based on either protection.
- Keep an eye on the pending appeal. The June 2026 ruling isn’t final, and Hessen’s government has said it’s working on a corrected regulation, so this page’s description of the current status may shift.
Compliance Note
This page explains the general rules and a currently unresolved legal dispute affecting condo conversion protection in Frankfurt, but it is not legal advice, and the court ruling described here was not final at the time of writing. For your specific building and situation, confirm the current status with Mieterschutzverein Frankfurt or a lawyer specializing in Mietrecht before making decisions.
FAQ & Common Pitfalls
How is Frankfurt's situation different from Berlin's?
Structurally different, not just a different number. Berlin runs a single, unified, citywide protection that's actively in force through 2030, no expiration drama, no zone-by-zone patchwork. Frankfurt has two separate, weaker mechanisms instead. The permit requirement to convert a building at all now only applies inside 14 specific Milieuschutzgebiete, not citywide, after the broader rule expired on schedule at the end of 2025. And the extended eviction protection after a conversion sale is tied up in the same court dispute affecting the Mietpreisbremse, currently treated as reverted to the federal 3-year minimum rather than Hessen's designed 8 years. If you're comparing notes with someone in Berlin, don't assume their protections apply here, they genuinely don't right now.
How do I find out if my building is in one of Frankfurt's 14 Milieuschutzgebiete?
Frankfurt's building authority maintains an online planning tool, planAS.frankfurt.de, where you can look up your specific address against the designated zones (identified by codes like E2Ä, E4, E5, E7, E9, E43, E44, E47, E50 through E53, E55, and E56, covering parts of Bockenheim, Nordend, Sachsenhausen-Nord, Bornheim, and Ostend among others). If your building falls inside one of these zones, a conversion permit is still required under paragraph 172 BauGB, the federal preservation-area law, independent of the expired Hessen state ordinance. If it falls outside all of them, the landlord currently doesn't need a conversion permit at all.
If my building is in a protected zone, does that mean conversion is blocked entirely?
Not entirely, but it's genuinely restrictive. According to Frankfurt's building authority, permits inside Milieuschutzgebiete are only granted in specific statutory exceptions, not as a general option: when the conversion happens through an inheritance division among heirs, when a family member takes over a unit for their own occupancy, or when the owner commits in writing, recorded in the property deed, to sell converted units only to their existing sitting tenants for a period of 7 years. Outside those narrow situations, a straightforward conversion aimed at selling to the open market generally won't get approved inside a Milieuschutzgebiet.
What actually happens to the extended eviction protection after a conversion sale right now?
Under Hessen's Mieterschutzverordnung, Frankfurt (along with the other 48 designated Hessen municipalities) was set to have an 8-year Kündigungssperrfrist, meaning a new owner who buys a converted unit generally can't evict the sitting tenant for owner-occupancy (Eigenbedarf) for 8 years, well above the federal default of 3 years. On June 10, 2026, the Amtsgericht Frankfurt ruled (case Az. 33029 C 130/25) that Hessen's November 2025 renewal of the entire regulation was invalid, the same ruling covered on SettledIn's Mietpreisbremse page, and that ruling knocks this protection back to the federal 3-year minimum for anything dated from December 2025 onward. The ruling isn't legally final and is expected to be appealed, so this could change again, but right now, courts in Frankfurt are treating the shorter period as the operative one.
Where should I actually go if I get a conversion notice for my apartment?
Don't try to work out which of these two rules applies to your specific situation on your own, the permit question depends on your exact address relative to the 14 zones, and the eviction-protection question depends on exactly when your building was sold and whether the pending appeal has changed anything by the time you're reading this. Mieterschutzverein Frankfurt am Main e.V., at Eckenheimer Landstraße 339, 60320 Frankfurt (069 5601057-0, info@msv-frankfurt.de), can check both questions against your actual address and timeline, which matters more here than in cities with one straightforward rule.