Plastic windows in the apartment: retrofitting ventilation

No idea what this thing needs or does, but if you move out of my apartment and leave drill holes on the window frames without consultation, which are not selectively necessary to permanently install shading on the inside, then that is property damage. And I am also a nice landlord!

Huh? I don’t leave any holes, but a fabricated ventilation that you can hardly distinguish from one delivered together with the window. But basically I understand your point. In the end, that is actually your business. But with her, nothing works if you don’t organize it yourself. You can wait for my landlord for years. And I wish for technical advice, not legal ;)

Ask the landlord if you are allowed to install window rebate ventilators. Ask if you are allowed to do it yourself. That way you would be on the safe side. Make a conversation note and tell the landlord that you are making one. He will get a copy of it. Then you can cut the sealing rubbers and install the rebate ventilators. If V. says no, then don't.

Ask the landlord if you are allowed to install window rebate ventilators. Also if you are allowed to do it yourself. That way you would be on the safe side. Make a conversation note and tell the landlord that you are making one. He gets a copy of it. Then you can cut the sealing rubbers and insert the rebate ventilators. If V. says no, then don’t.

For rebate ventilators you only have to cut the sealing, right?
Sorry, but I wouldn’t even ask my landlady about that. The sealing costs nothing and I have already renewed it myself. If I asked about such little things, I’d be sleeping on the floor and washing my face in a bucket :D
If worse comes to worst, I’ll install a fresh sealing when moving out or the next tenant has ventilation. Who can say anything against that?

Ask the landlord if you are allowed to install window frame ventilators. Whether you are also allowed to do it yourself. That way you would be on the safe side.

Not necessarily. If it is a condominium, the owners' meeting would even have to decide whether the OP is allowed to do it (if you want to do it properly). Because then the windows are common property. *Know-it-all mode off*

Two screws into the window are also necessary per module. At least for Regel Air.