The flat, although on the first floor, is perfectly quiet.
We were authorized to leave our suitcases before the flat was ready and if we had wanted to we could have left them after checkout.
We found that Airbnb in Berlin are terribly expensive, but at least this one was nice, well equipped (except no dishwasher :(), and the host was lovely.
She left some sweets,fruits and water which is a nice touch.
Thanks Carolin.