[xavieralexandre]

You are not forbidden at the Federal level to have fixed units.

But many states do indeed requires a permit to install fixed units. And have strict regulations such as self producing half of the electricity required by the installation.

Here are a few examples of such regulations:

- Geneva (the most strict state): https://www.ge.ch/installations-techniques-rafraichissement/...

- Fribourg: https://bdlf.fr.ch/app/fr/texts_of_law/770.1/art/16

- Vaud: https://www.vd.ch/fileadmin/user_upload/themes/environnement...

One of the side effect of such regulation is that many business and houses will use cheap non-fixed units with open door and windows instead of installing proper reversible heat pumps.