Active job

Damp in bedroom, water coming in

I have a freshly refurbished house but my builder sadly did a lousy job and it seems now water somehow is coming in and ends up underneath the floor boards. Or maybe the water is not leaving the cavity in the weep holes and just stays there. It is quit depressing as the room has this distinctive damp smell what is coming from one corner of the room and we simply can not use the room this way. I would need someone who takes a look, opens up the wall if needed and fix the problem once and for all. Then the wall needs to be gib boarded back (if you made a hole) and possibly make it nice. If you need to remove the floor boards then that would need fixing as well. I have added picture of the corner of the room, but It does not show much, I know. The building is a 1970s single storey, concrete floors and foundation, cavity walls. I could not find better work type so I posted to waterproofing/joint sealing. Thanks a lot, Peter