Re-introduceing an old Sketch

Takeing Phil's advice, I thought to myself on how I could improve on my space, makeing it bigger, but I also thought;  "I can't do much in a box" so, I took the camera out of the basement and into a hall-way just beside it. though, now my question is; How do I get the walls to look seperate without bluring them together in a total mess?

the 'glow' in the bottom Left, is (going to be) from the Mushrooms which are said to glow. the rest is natural light.