Floor plan / Bungalow - Ideas, suggestions, tips?

And please make it switchable, it is not supposed to be a burglar-proof socket ;-)

good idea. Frost-proof water taps should also be able to be turned off from the inside, right?

We can turn off our internal supply (1 valve for all). All external sockets are connected to their own RCD, which is simply switched off when we are away for a longer time.

Frost-proof faucets should also be closable from the inside, right?

The frost-proof faucet itself ensures that the shut-off of the water supply is moved into the warm area. You don't have to double up on that. As long as you don't fear that your neighbor will use your water for his sprinkler during your vacation, it's actually not necessary.

During the vacation, I turn off the water meter, then surely nothing will happen. I worry if, for example, young people on the weekend are on their way home from the disco and want to drink tap water but forget to turn it off. About the windowsill height of the window in the utility room, I think it makes more sense if it is relatively high, so that a small cabinet can be placed in front of the window, right? (101 cm wide and 76 cm high)