The city ordinance says that it must be at least 32 sq ft. I'm going up this weekend to the Little Coop on the Prairie people in Rhome to look at one they're building for someone else, and talk options - it looks likely that I will have them build a coop and run in one for us. I have been convinced by the various coop threads to a) avoid the prefabs and b) make sure I get it done right the first time. I'm semi-handicapped, my daughter's in high school, and the other two adults in the family - one works full time, the other works full time AND is a part-time writer, so 'build it ourselves' is not the way to go. I'm going to talk to the coop people about possibly going bigger than the 32 sqft, given that bill in the house/senate that might enable me to have a future flock of 6 instead of 3.
https://lccotp.wixsite.com/coops