Protection from my rented room being search (search Warrant)

There is not guaranteed to work but it should.  If I was you, I would put a note on my door saying:  "My name is__________.  I am the sole occupant of this room.  I do not give consent to anyone to search this room. "If there is  a lock onthe door you should keep it locked.  In any case the door should be shut.

Assuming that your roommate is on probation or parole, with a search clause, the ability to search should be limited to his room and the area that he has individual or joint dominion and control over.  This would not include your room.