From your picture, I would remodel. Chickens like to roost as high as possible (trees, if they could!);
I would place the roost BOARD, not a pole- chickens do not have feet like songbirds, that have toes to wrap around. 3 inch board gives them stability and in winter, body covers the feet to keep them warm. Across the narrow end, and 10-`12 inches from the end wall, at least--further, if their tails touch the wall. Place a shelf below the roost , about 6 inches below. It will catch all the night poop and keep the floor cleaner=and is easy to scrape clean every month and avoid bad smell. You need another roost board maybe just 2 inches wide, in front and below the roost shelf and roost, to fly up to (they LIKE to fly and just not too high for the first flight up; to roost. High enough that you can service the birds on the floor without banging your head=. You will have room for your feeder and water at the other end of the coop--up on blocks of some kind, so they will not scratch bedding into them. And best to have some kind of raised "box" for the waterer, so the floor will NEVER be wet around the waterer. For 4 hens, it can be a very nice set up. Oh, nest box (1 is enough) could be on another shelf just below the roost shelf (with the 2" board in front to land on to enter the nest box, as well as the flyup to the night roost==all the built ins on one end. plenty of room to move around the rest--easy for both you and the hens. Good luck .