Outdoor water tap was not connected!!!

The idea of the rain barrel is nice, as with cisterns, but the disadvantages are taken to the extreme: when it is needed, it is empty and the costs cannot be recovered.

then the lid is not sealed. We don't have any.

Check your pictures from the construction phase to see if the tap really isn't connected.

I'm not really a fan of inviting mosquitoes to the house either. But still a good idea that I want to implement with the garden shed....

I am a layman in craftsmanship and am asking again out of curiosity because I didn’t understand it. Problem with understanding.
Where is the tap not connected and how does that work?
With us, the pipes were laid. The pipe sticks out of the wall and then the outdoor taps are mounted on it. How do you mount them without a pipe??
Or was the pipe only run to a certain point and just stops there?
But that would also be a service of the plasterer.
Don’t you have any more pictures from the shell construction?

Just google "Außenzapfstelle," then you will see that there is a long pipe stub built into the wall. The part that extends inward was not connected. That’s why I was also surprised that the plasterer didn’t notice anything...

The matter is quite simple. The outdoor water tap was ordered and must be delivered at the agreed costs. You have already received a partial delivery. Now I would ask the installer to make improvements and to describe how he intends to do so. If the risk to you of "kitchen damage" and the inconvenience of "dirt" are too great, another solution can be sought. Chasing the installer to hell is not productive, because he is not necessarily bad or unreliable. A mistake has happened - however - and now one simply has to deal with it. Pipes can be laid both inside and outside the house up to the desired point and protected against frost - so there is also a way that does not affect the kitchen. The offer for the first maintenance is an affordable solution for the installer - you have to assess for yourself whether the value is right for you. Who was in charge of construction management? What does this person say?