KfW Program 440 - Charging Stations for Electric Cars - Wallbox

But I suspect that many (including myself) who have built in the last 2 years and have already moved in have a heavy-duty power cable lying around the garage or carport exactly for this purpose. Meaning, just buy, wire it outside, and screw the box on. For everyone else, it won't stop at the 2k or whatever you estimated, because it probably also means digging, laying cable, and then repaving.

However, I only have 5x2.5 secured in the garage with 16A.

That's exactly right. That is why my advice to the OP is to make all the preparations immediately.

At the electrician of our general contractor, it was said in the preliminary discussion that it was only the high-voltage cable.