You will do better by starting a new thread. You can copy/paste this post in it.
For your situation, I recommend a Woods' Open Air build or a shed conversion (either existing sheds or modifying shed plans if you build from scratch).
Shed conversions are usually the most cost effective, durable, easy to buy or build, easy to use options. "Easy to use" means easy to fit everything in - like roosts higher than nest boxes and yourself into it to care for the chickens or clean it.
The con is they need some building skills and tools and time to convert them. Not many skills or tools or time for basic functionality but some.
Oh, and they usually cost more unless you already have a shed or can find (and move) one used.
Sheds need conversion because they never have enough ventilation. At a minimum, open up the eaves and add some other openings. I left the entire side open (in a colder climate than yours) and it worked very well.
Cupolas are wonderful but harder to build.
Windows or vents might do – think square feet of opening, though, not square inches. Considering the
cost of repainting the interior of a house, it’s important to plan carefully. Twelve chickens need twelve square feet of ventilation openings at a minimum. More is better.
Windows don't count as ventilation when they are closed so either design them to be open even in bad weather or have enough other openings.
Ridge vents in the roof count as long as they aren't blocked by snow. Some brands are designed to not be blocked even when covered by snow. Ridge vents add inches more than feet but quite a lot of inches and their location helps them work better than some other options.
Having the roof overhang the eaves by a foot of so is worth doing.