Rent usable space of a multi-family house individually

Hello everyone,

In my circle of acquaintances, everyone is currently building or buying used properties. Now a friend described a situation to me that I didn’t know how to advise on, and I thought I’d share it here.

The friend bought a house with a separate staircase and an apartment on the ground floor, one on the upper floor, and an attic that can be used as living space.

He wants to move into the ground floor apartment in a few years and until then rent out the apartments. The ground floor and upper floor apartments are sealed off and designated as living space. The basement would mostly be assigned to the ground floor apartment and one room would be assigned as storage space to the upper floor apartment.

But now comes the problem: The "apartment" in the attic (including kitchen, bathroom, etc.) is not designated as living space, it is designated as utility space. The friend would like to rent out this attic as an additional unit provided that none of the ground floor or upper floor tenants are willing to rent the space additionally as utility space.

Now the question is, can he even rent out the attic separately since it is designated as utility space? Or can he have the attic reclassified as living space afterwards?

Maybe someone can help. Then I could pass on the answer.

Best regards HB1

If this area has been developed but is officially only usable space, there will be no building permit. It is an illegal construction - is that the correct term?

The question is why it is not considered living space. Do the sloping ceilings not meet the required living room height? Could the structural integrity possibly play a role? Are there escape routes? Either the homeowner knew about the problems and built secretly, or the authorities had doubts and it was still developed.

Anyway. Whether this dwelling can be rented out (basement rooms and garages can also be rented): I think so, for example as storage space or simply usable space. Now one might say: it doesn’t matter what the tenant does there, but I see a problem in that: Living rooms are subject to conditions, e.g., sufficient light and air. One can simply assume that standard-compliant building was not observed. In this respect, staying in such rooms can be life-threatening, for example if the structural integrity does not hold, the air circulation is inadequate. Possibly the chimney is not sealed, etc. Fire protection? As mentioned above: escape route? I consider it negligent to rent out this space, probably with the landlord knowing that these points of danger cannot be ruled out.

Those would be my thoughts.

Regards, Yvonne