. I suggest lowering the lighting a bit. After that I would around the arch of the door add some dirt and mildew, maybe some cracks as well 
. Then at the bottom of the doorway like in the image, you could add some cracks to the bottom of the doorway. Then you see the walls? I think like in the image attatched if you gradiented a dirty look, so that it almost looks like everything else around it is semi-clean.. and then the closer you get to the door the more wrecked up, dark and mildewy it gets . Just some suggestions, coming along great though .
