No, air conditioning is not illegal in Switzerland, but it is much more strictly regulated than in North America or other parts of Europe. In 2026, the installation of "fixed" air conditioning systems (like split-system AC) in residential homes and apartments generally requires a building permit and, in many cantons, proof of "necessity." This is because Swiss energy laws prioritize environmental sustainability and the reduction of electricity consumption. To get a permit, you often have to prove that the indoor temperature cannot be lowered through passive means like shutters or natural ventilation. In commercial buildings and offices, AC is more common but must meet high energy-efficiency standards. For renters, the most common solution is the portable (monobloc) AC unit, which does not require a permit because it is not a permanent installation. However, even these are subject to noise ordinances; you can be fined if your AC unit disturbs neighbors during the strictly enforced "quiet hours" (usually 10:00 PM to 7:00 AM). Because Swiss summers are becoming hotter, the laws are slowly evolving, but the country's default "cooling culture" remains focused on thick walls and external blinds.