The bottom is the most important part - I should have addressed that!
If you have a good sandy clay or solid flooring (cement, wood, etc) as I did, I decided not to place any wire screening as a floor. The chickens love scratching inside of their pen which would be impossible with wire. Besides, I think wire could hurt their feet.
That being said, we learned the hard way about the safety of the flooring - our first four chicks were taken by Racoons who just dug under the 6" x 6" posts we set the tiny coop on in the beginning. We then sat that little coop on cement. But it was a very small coop and fit under our Truck carport with the truck - no problem! Then as they grew and we knew we wanted a larger coop, we decided to move it behind our garage - out of sight and far away from smell when we entertained outside.
What a pleasant surprise to learn (from others online) that sand was one of the best floorings - the chickens LOVE their cage bottom, the rain washes the poop thru' the sand and it requires just adding a bag of sand from time to time and a bit of raking now and again.
Now - how to keep the critters out!! Again, online, I learned to bring the screen (we used 1/4" hardware cloth as chicken wire contains the birds, but other creatures can break thru' it) all the way to the ground and extended it out one foot all the way around!! We then put more sand and some stepping stones on that apron of wire. The little critters don't understand that they must start a foot out to dig in, therefore they are digging onto the wire! Brilliant!! We've had them there for about 6 months now, and since we live on the West Pearl River, have our share of creatures!! There have been no breeches in the security of the coop.
Now my Ladies do free range during the daytime (hawks are a concern, but I cannot cover the whole backyard!) but at night will run to their coop if we haven't put them away first. They are happy, contented, friendly hens, all of them loving to be petted and held!! (well, three of them enjoy it, one puts up with it!). We get four eggs a day -EVERY DAY - a blue one, two brown ones and a white one.
If your coop is set up properly, you will find it a cinch keeping it clean. Once a week or every 10 days, I fill one of two 7 pound feeders, one with layer pellets and another with larger pellets. I fill a small feeder with oyster shells and have THREE galvenized watering buckets (the BEST method after numerous trials with other waterers) and one out in the yard as well.
I go in and rake up any poop that I can and throw it in the composter (also newly added to use that poop), and I am out of there in about 20 minutes!!
So, for 20 minutes once a week or longer, my Ladies give us four beautiful eggs a day. I really thought it would be more difficult, but it has been a breeze!!
The A-frame has a wonderfully large footprint for the Ladies, but doesn't seem so big and looming as a square coop. I know it takes the same space on the ground, but it just looks smaller and less intrusive.
I hope I have answered your questions. Most of the lumber we used was weather treated and 8' long, so the coop is basically square at the bottom.