“At one point the entire house was almost empty,” says Tim Propst*, who shares a shared apartment at Mindener Straße 3 in Charlottenburg with two roommates. The 28-year-old is standing at the window of his room in the back building. Many apartments became available at the same time. “It could actually be very pleasant here,” he says – if the landlord didn’t want to get rid of the residents.
There is an eviction notice on Propst’s desk because of personal needs. It was issued by the main tenant of the apartment, Sascha Kalb, who refers to a fixed-term tenancy and personal use. According to the commercial register, he and his father Michael Kalb are managing directors of “Apios Fünfte Verwaltungsgesellschaft UG”, which owns the majority of the apartments at Mindener Straße 3. Brother Mischa was also involved in the company management until 2025.
Propst, who has been renting at Mindener Straße 3 for four years and completed his architecture studies last year, doubts whether the time limit on his sublease agreement was legal. The Apios entrepreneurial company has also worked in several other cases with similar fixed-term constructions, sometimes with chain fixed-term contracts, in order to create “unstable tenancies” and to enforce regular rent increases.
Documents available to the taz confirm this at least for one other case. Tim Propst explains that rental agreements for other apartments were repeatedly limited for years with vaguely worded announcements of personal use and renovation measures without the renovations ever being implemented. A taz query to Kalb remained unanswered.
There is something rotten in Berlin, the capital of tenants: Investors are speculating with entire blocks of flats, corporations are letting their buildings fall into disrepair, tenants have to deal with eviction notices and exorbitant rents.
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When asked by the taz, the Berlin Tenants’ Association explains that in practice such constellations are often not permissible temporary rental agreements, but rather abusive rentals “for temporary use”. The time limits are then ineffective and the tenancies are legally considered to be unlimited.
It suddenly became quiet here
Niklas Schaefer*, tenant
Propst’s roommate Niklas Schaefer* has also been renting on a temporary basis at Mindener Straße 3 for four years. Last year was the worst, he says. The owner company let all of the temporary rental agreements in the building expire in August 2025: “It suddenly became quiet here.” Around 15 tenants with chain rental agreements moved out in a very short time. Only Schaefer and Propst’s shared apartment and another shared apartment in the front building objected to the move out.
The two roommates accuse the owner family of neither using nor renovating the empty apartments for their own needs. Instead, some have already been resold, others have been empty for years.
A press spokeswoman for the Charlottenburg-Wilmersdorf district office told taz that the district was only officially aware of one vacant residential unit in the property since 2022. As of February 2026, the vacancy process is still ongoing. However, a look at the mailboxes in the stairwell shows that several mail slots in the front building alone have no name.
Just one of several companies
The “Apios Fifth Management Company UG” with its registered office in the Brandenburg tax haven of Zossen is just one of several companies that father Michael Kalb and his sons Sascha and Mischa run in changing configurations. Research in commercial registers and company databases shows a network of at least twelve GmbHs and UGs in which the family has a stake, including several real estate and management companies based in Berlin and Brandenburg as well as in the Rhine-Main region.
While the city’s real estate giants and their rental practices are regularly reported on, smaller housing companies often go unnoticed. The example of Mindener Straße 3 shows that they can also work with systematic rental strategies.
A house is falling into disrepair and the authorities are powerless
Sophie Goldschmidt*, tenant
The Kalb family apparently takes a similar approach in other Berlin houses. The situation at Straßburger Straße 42 in Prenzlauer Berg is particularly serious: here the residents are fighting not only against fixed-term rental contracts, but also against the progressive structural deterioration of the house. According to the commercial register, the owner is “Davalia Anlagengesellschaft mbH”, Michael Kalb acts as managing director, and son Mischa assists as authorized signatory. Here too, a taz query to the landlord remained unanswered.
Lisa Schultz* has lived in the house near Senefelder Platz for eight years. The 31-year-old archaeologist says that the temporary rental agreement for her shared apartment in the front building has been extended five times since then. She experiences this as “a state of permanent uncertainty. For years we have felt that we were tolerated in installments, but not wanted.” The contract is now scheduled to finally expire on March 31, 2026. The reason given by the landlord was a planned core renovation.
Leaky roofs, defective heating systems
Many residents find this unbelievable. Schultz reports that no serious maintenance work has been carried out for years. Instead, the tenants suspect that the apartments should be sold empty. According to tenants, the district has been presented with rental agreements in the past whose actual use they doubt.
The Charlottenburg-Wilmersdorf district office responsible for misappropriation replied to the taz that there were five vacant apartments in the property. The owners were asked to rent out the apartments again – otherwise they would face a fine.
Sophie Goldschmidt* has lived in the house for 23 years. She accuses the landlord of violating basic obligations: “Here a house is falling into disrepair and the authorities are powerless,” says the tenant. Goldschmidt lists the defects: leaky roofs through which rain penetrates into the apartments, defective heating and hot water systems, plumbing systems that were not repaired for months, and pieces of plaster and ceilings falling down in the hallways. There were unsecured holes in the yard and the front door had not been able to close properly for years.
“You live here constantly with the feeling that anything can happen,” she says. The owner family “from the Frankfurt suburbs” does not know the responsibility that comes with owning living space in this city – and certainly does not feel it. Schultz agrees. It is clear who is responsible for the condition of the house. Apparently not anyone who can change it.
* Names changed