I live in a house owned by a housing association that is absolutely terrible with maintainance and so I wish to take matters into my own hands with a bathroom that is in truly a terrible state. We are the second residents in this house and the this area has been like this since we moved in. My question to this forum is how bad is this damage and how do I go about repairing it? Thanks alot.
Looks like a combination of water damage and mold around a sloppy and minimalist tile job, but you should realize that depending on the nature of your relationship to the housing association, "taking matters into your own hands" could have serious financial repercussions (and possible eviction repercussions.)
Evidently, the required fix would be to remove the damaged and moldy material, and preferably replace with tile backer or other tile substrate suitable to the wall's construction method, and expand the area tiled to encompass the area of water splashing on the walls. A waterproofing membrane or liquid-membrane product either behind or on top of the tile backing is needed, since tile is not itself waterproof.
You might be better off looking for a new place to live, unless you can get permission to do this work yourself ahead of time. It's a pain, but it's also the best way to deal with a landlord or landlord-equivalent that is "absolutely terrible with maintenance."
You've got some serious water damage, mildew/mold problems. Not sure what the tiles were for, maybe to hide more damage. Your fix would be to remove all the damaged wall board, plaster down to the studs and then determine if they were bad too. Then replace the wall portions you removed. You would also want to determine where the water was leaking from and fix that.
If this is a rental, you'd want to get permission to do any work. If you don't, you could be held liable for existing and future damage.