What will hit you before that here in Switzerland is the local authorities which have in front of their eyes a certain plan for your building, and anything not

What will hit you before that here in Switzerland is the local authorities which have in front of their eyes a certain plan for your building, and anything not on the plan (in this case the AC unit) will need a permit. It's not an easy task, I would say impossible actually, to get such a permit, unless you find a way to redesign the whole facade in a acceptable way (units poking out doesn't count as acceptable).