Multi-family houses (at least 4 residential units) built before 1990 Purchase price between EUR 300,000 and EUR 1,500,000 also real estate with investment backlog or "problem real estate" net return of at least 6% / factor 16 Rents also below the market level Bathroom in the apartment, good floor plan, cellar compartment or other storage space, ceiling height not below 2.40 m, bright apartments, no long-term lease