What do you mean the AC units are not allowed in Western Europe? I lived in Germany and never heard of this. In my experience, it's mostly cultural. The French for instance expect a "canicule" once or twice a year and that's generally survivable, although I think they are realizing that their frequency and power are increasing, so we might see uptake in air conditioning.

Edit: Or perhaps you meant regulations? If so, then yeah those exist, such as permits for the building and so on.