Ive spent several hours looking through all the designs here...WOW. makes me want to spruce up my stuff. I built my coop/runs from limited funds and keep functional in mind. Since our power service was on the same side as the chickens i had to come up with a plan that worked around it, so it doesnt totally block the power guys access...The 1st run thats attached to the coop is a 10x10 plus easy access for the birds to go under the coop on those hot summer days. After getting a few more chicks i figured i woul enlarge the run a bit, so heres what i came up with. Using 3 55gal barrels free from my dads shop, making a tunnel leading to the 2nd run. 2 of the barrels are bolted bottom to bottom, cutting out about a 18/20" hole in the bottoms. The 3rd barrel is attached to the 2nd one mouth to mouth with the original steel lid band..I did have to cut the 1/4 lip off one barrel to make the ring work, but it left both flared lips to tighten on..worked Great, and solid as a rock. The second run was made from another freebie donor4ft high 4 panel dog lot.. i did have to buy the top wire, and 2ft hard ware cloth to go around the bottom for fox/weasel protection. Not only do the barrels serve to link the 2 runs, i put a layer of dry sand with a bit of DE for mites inside the tunnel which gives them a nice "Dirt bather" to play in. !st 2 days the birds wouldnt go through, but after coaxing them with some fresh corn nibblets they started using it, now they wont stop...its like a constant playground for them, my kids are tickled..