10cm brick wall carrying capacity for additional beams
I would highly recommend that you come up with a plan that uses legs on this bed construction that come all the way down to the floor. This way you do not need to fasten into the wall at all. Such a construction can also be easily disassembled for moving from room to another room or another dwelling. You also avoid messing up the wall. 

Long legs on an elevated bed will need to be constructed so as to prevent racking of the structure. One way to achieve this would be to put a skirt board around the legs on three sides near the bottom. Some angular bracing may also be necessary.