Now I won't go into all the poor craftsmanship in this house but safe to say when it was converted it from a shop they were absolute cowboys.

To put a long story short the initial thought about this problem was the guttering being blocked, water soaking through the wall, valid point and that got replaced. The mould cleared away, wall dried, stainblocked and painted.
Today I've been back in there and the wall is absolutely soaking in the bottom corner, and the carpet. Theres no problem with ventilation, it's definitely not natural condensation in that amount, which was the other thought. It's like someones chucked a jug of water on the wall.

So I've had a thought, theres a bathroom underneath the room (well two, but one directly underneath the problem) is it possible it could be the steam from that. Baring in mind the extractor fan in also in that corner, or am I barking up the wrong tree here?

It's also damp up in the top corner but not to the same extent, how would I check if it's an issue with the roof. I've not bought my roof ladder with me here so I can't access the roof itself. Looking out from the window which looks out onto that roof though it looks to be in good condition on the surface, and it's not been raining hard recently.
Or is it the structure itself? It's rendered (badly)

One final point, this room is not insulated and it's quite cold if that could be a factor. We've been moaning at the landlord there for ages to get insulation blown in there.

Any thoughts UHM'ers? I'm not exactly learned up about damp proofing and such.

Don't suppose a few pics would help?

I wouldn't worry about it, let the landlord sort it out.

Landlords useless, he's been "sorting it" for over a year now.
I said to him get the builders out, I was told monday it's now wednesday and the guys haven't shown up, I give it several weeks. Whether thats him or the firm I don't know but my housemates refusing to pay him rent until he sorts it.

I was also hoping to sort it and bill him for it if it was an obvious problem seeing as I've got no work on at the moment. Housemate gets her room sorted, he gets his rent, I get paid.
But seeing as no one seems to know I'm guessing it could be just about anything? Better to leave to the damp experts.