Is that built remotely and transported to you or will it be built on site? If remotely that may be the size you need to avoid transportation permits but if it is built in place you might get a better price going with an 8' x 8' since most building materials come in standard 4' or 8' dimensions. Less cutting and waste. Both are about the same size and should be adequate for 6 chickens.
If that is built as well as it looks you should never need to lock them in the coop section itself as long as you provide dig protection. I'd suggest an apron, which you can easily add yourself. Basically you have an 18" to 24" apron around the outside so a animal goes up the the wall, starts to dig, hits the wire, and does not know to back up. Very effective and easy to do. If you never lock them in the coop section they have the use of the entire area at all times so coop-section size is not relevant as far as containing them. The whole thing is the coop/run.
I don't see a lot of reason to even have that interior wall. I like flexibility and having the ability to lock them into or out of the coop section only might come in handy, but I'm not seeing any other benefit. Why do you need it if the whole thing is predator proof? It would sure open up the inside and you would need only one exterior entrance door, could reduce costs.
Unless you have a good reason to gather eggs from outside the coop I would not bother setting that up. Putting nests accessible from outside the coop/run adds to the complexity of the build, increases your costs, provides a possible weak spot in your predator protection, and may leak if not done carefully. Many people have good reasons for having nests accessible from outside, I'm not arguing that good reasons don't exist. For some coops it is necessary. Just something to consider for this one. You will have plenty of room either way.
I think someone mentioned this. It looks like rain could come through that wire and get the nests wet. You do not want that to happen.
I cannot tell if that roof has a slope or not. You do need a slope and you do not want the rainwater to run off over a door you are using to go in and out.
This may be more personal preference than anything else, but I prefer a hasp-type lock on the doors with something like a carabiner to lock it closed. I just feel it might work better to stop a raccoon. I do like the heavy hinges he is using, hardware needs to be robust and can get expensive.
I suspect your winters and especially early spring might be a bit cool and moist. That's a recipe for you to get a lot of condensation on that metal roof which can drip inside. My metal roof did that when I was in Arkansas but my overall coop was so dry and the ventilation was good enough that it was not a problem, it soon dried out. A lot of outbuildings have metal roofs like that. For some people it is a real problem, for some it is not. You might consider having it insulated to start with or watch it to see if you need to do something if it is a problem.
I see that the coop has a dirt floor, so does mine. When you position that coop you need to put it where water drains away from it, not to it. Putting it in a low spot where water collects is a huge mistake. You may want to haul in some dirt or sand to put it on so it stays dry.
Overall I like it. It looks solidly built and is tailored to your climate. Good luck!
