I am a PhD student, non-EU resident with B permit of type "Formation avec activité" (it's neither a student permit nor a work permit, something between the two I guess!). As I'm a PhD (research assistant), I have a contract and a regular monthly salary.

Now just a quick question: Am I allowed to buy a house in Switzerland with my current permit (as my principal housing, and not to rent)? Or is it required to have a B work permit for that?

Buying a house as a EPFL PhD student???? May I ask what your Daddy is doing?