This run took far longer to build than I anticipated thanks to the summer of never-ending rain here in Georgia. It was built flat in sections, the same way as the coop. You can see all four sections stacked here.
I used concrete blocks on a layer of paver gravel and sand for the base.
Here the pre-built sections are up, attached to studs which are in turn attached to the barn supports through the metal siding with lag bolts. Using rafter ties made putting the rafters on without cutting angles very simple. (I'm bad at cutting angles...)
I used the same cedar waterproofing stain as the coop and added a corrugated metal roof. It's important to note that while my run is enclosed with poultry netting, this would not be sufficient to keep large predators like dogs or coyotes out. My yard is securely fenced on all sides, and the hens will be secure inside the barn every night thanks to the aid of an automatic door. Unless the raccoons develop thumbs, they're not getting in. If my yard weren't secure I would have used hardware cloth secured with screws and washers.
I wish I had a picture of everyone running around in their new pen, but after a day this is as far as one little pullet has ventured out! I guess it will take them time to pluck up some courage.