OK, we really learned the hard way...My husband built the first coop, and it was so awful, it is now torn down and has been replaced. Two problems, one was I had to lift the roof to collect the eggs. Hubby doesn't always have "open ears" to what I'm saying, and that hinged roof, first of all, leaked at the hinge area, and secondly was heavier than heck! I injured both of my shoulders because I had to lift it, hold it while I hooked the chain that kept it open, and collect the eggs. I spent the whole summer healing.
Now, I bought a small animal barn from Craigslist, (used) 8x12 with two rooms, for only $650.00. What a deal that was! My chickens are in paradise!
Anyhow, my idea to share is simply using sand in the run. I've tried every type of materials for the run floor imaginable, and the sand is the very best. Rake it up and it's clean, no smell, if it gets wet, no big deal! I'd advise everybody to use sand in the run.
Not a very original idea......but, compared to straw, sawdust, and just plain mud, it is awesome!