Here is my open coop/run in California. Because of our weather, I decided on simply sectioning off a portion of the run and adding plywood on three sides. That is where my chickens roost but I"m not actually sure you can call it a "coop." On cold nights (temperature here will occasionally go into the 30s at the coldest), I will drop a tarp down from the roof to create a fourth wall, if necessary. My four girls have 24/7 access to the run (which is 5x15) and are allowed outside in a fenced in area of my garden when I'm around to supervise. Because I was worried mainly about raccoons and rodents, I used hardware cloth underneath the entire coop and (because I'm paranoid) it is also under the plastic roofing on the top of the coop. The nesting box is the nightstand and I use a bucket auto feeder and nipple-system for water. The ultimate plan is to go deep litter but I did not gather enough leaves in the fall/winter (when I first had the idea for chickens) so I currently only have about an inch of litter substrate. It is still working pretty well as long as I fluff it frequently but I look forward to actually making the litter deeper when I have some more free materials in a few months. I went for simplicity and (hopefully) security over cute and cuddly. If there are any doable modifications (if it requires completely tearing down what I have and starting fresh, don't tell me!), I'd love to hear your thoughts.