Apartment rental cancellation by the landlord

Renter in Munich rents an apartment from a private Owner. Owners says they may need the apartment should they have to move back to Munich.

Renter is only in the apartment for two weeks and the Owner turns up and says 'Can I have my apartment back as I am returning to Munich - you must find a new one as soon as possible so I (the Owner) can then move back in and we can cancel the lease (lease has 3 months notice for either party) and give you back he deposit'.

The Renter is pissed off because:
They are still waiting for the return of the deposit on the previous apartment.
They have given a new deposit on the new apartment.
They are being asked to find a new apartment that in turn requires another deposit.
They have just moved (hassle, time and costs).

Is there any laws that allow the Renter to at least stay in the apartment for a reasonable period i.e. 6 months or 1 year?

The renter has every right to be pissed off and to demand three months' notice.

Renter is legally entitled to three months. Maybe the owner could buy them out of his obligation, which is essentially what the renter has to do if they give less than three-months notice. Difference is that the owner holds on to that money. So the question is... how badly does the owner want to move back in?

Eigenbedarfskündigung des Mietvertrages durch den Vermieter ...

The owner says it is urgent but they have somewhere to stay until the Renter vacates.

That's a tough situation. Obviously the owner hadn't fully thought things through before renting the place out. The renter probably doesn't want to be a jerk and demand their entitled three months, but the owner should recognize the position they've put the renter in. Hopefully there's a mutual level of understanding and the owner will be cool enough to allow the renter all the time they need to find anew place without hassling them. But the renter is legally entitled to three months. No advice here, I'm afraid. Best of luck to all parties involved.

my landlord told me i gotta move out coz he needs the place asap. now my colleague (a german guy) told me yesterday that he once was in a situation like this and sued the landlord, coz apparently they gotta pay you the fix cost for moving again and the deposit of the new place. but i dunno if thats really true. and wouldnt know where to find out. good luck anyhow

This is Germany, so the landlord needs to send a cancellation in written form till the 3rd of the month for the cancellation to be effective at the end of the 3 month notice period (so 3rd March, effective 31st May). In this letter, the landlord needs to explain in detail why he/she needs the apartment for themselves or close relatives (Eigenbedarf).

According to the link provided by Miwild and other sources, the Eigenbedarf could be "rechtsmissbräuchlich" (an abuse of law). The reasons for Eigenbedarf and thus cancellation need to arise after signing the rental contract. If the contract was concluded when it was foreseeable that they would soon need it for themselves, the contract would be in breach of good faith. The short notice of 2 weeks leads to suspect this. Usually people don't change plans every two weeks. If the contract was in breach of good faith, the tenant would be entitled to stay longer, but there are no set rules.

In any case, when receiving the cancellation letter, the tenant should object to it in written form (if they want to stay longer than the 3 month notice period), best done by a lawyer.

Thanks RainyDays and others. Naturally the Renter will most likey be consulting a lawyer. Just curious for any personal experiences out there.