In theory, the matter is simple: in the big cities, a similar number of households live in apartments that are too big and apartments that are too small.
If the two groups swapped homes, the real estate market wouldn't be nearly as tense.
However, there is no balance between the available space and the demand for space – also because it is not financially worthwhile.
The older the lease, the more favorable the conditions.
You can hardly blame pensioners if they stay in the family apartment that has become too large.
Owners, on the other hand, know that owner-occupied real estate can be inherited tax-free.
As long as politicians do not want to shake these principles in tenancy and tax law, they promote the "lock-in effect": everyone stays in their home as long as possible.
Some experts are betting that high energy prices will encourage more people to move into smaller apartments.
But it is questionable whether this calculation will work out.
Finally, there is always the option of simply not heating unneeded rooms.