Yeah it's me again, the hesitant, coopless newbie. I do "get it" about chicken math, and my intent is to have 3 or 4, but the math says I could double that, altho I really don't want to. My space is limited and I am working with a 9x9 area that is bounded by a tree on the right, my "barn" on the back and a ramp from the barn on the left. There will be a predator protected run that extends out in front of the coop for another 8 feet. The space is small, and the overhanging of the tree limits me even more. I do not want to trim my tree, but there is a nice niche between 6 o'clock and 11 o'clock where a 4 ft roof would fit. I was thinking a flatter style would allow a bigger horizontal space, and a nice pull-out drawer for cleaning would work. For those few chickens, do I REALLY need a walk-in coop?
My first coop was a raised coop, attached to the back of my barn to save materials, with an attached run which has been twice expanded and is now left open at all times. I did a lot of things wrong, and I hate it. What makes it tolerable (and full disclosure - its a good bit larger than yours, at 8'x12', is that when I open it up, there is no place I can't reach with a rake to clean it out, or a shovel to refill it with leaf litter. What my back loves about it is that the nesting boxes ore roughly "nipple height", so I open the door to those (hinge on bottom), look right into the nests, and gather all the eggs w/o stooping, or bending). The ducks lay theirs on the ground, and several years in, it sucks. Doesn't get any better, the back just gets older.
Do you have to have a walk in coop? No.
Does it make many things easier and more comfortable? Yes.
After ventilation and space for the birds, the most important (my view) is that you be able to access all of the coop easily. If you aren't building a walk in, then if at all possible, raise it to a comfortable height for you, and make sure one side opens in a way that allows you to easily access all of it with a tool with a handle. Does no good to be able to reach in with a push broom or a shovel if you can only move it a foot or so before the handles smacks into something. Smaller coops, at least you can uise things with shorter handles, which can help. I need a full size tool to reach the back corners, 4' from the colosest location I can access.