A consideration is to build a predator proof run and have a convertible roosting area. I don't have very many good shots of our old coop back in the suburbs, but it was a 12x12 run with a 4x4 area in one corner that was converted to a roosting area. During the winter, I had removable walls (just some hardie plank siding with a couple of 2x2s on the back to hold it together) and a sheet of plywood that was covered in vinyl to act as a poop drawer.
During the summer it allowed for the birds to fly to/from the roosting area (the roost area had permanent external walls to prevent raccoons from reaching in and grabbing the hens) and my nest box was a secondhand dog house that i hinged the lid on.
If I were to do it again, I'd have made the nest box accessible from outside, but otherwise it worked very well for us in the PNW.