Pressure treated wood would be OK but you don't need pressure treated wood for anything not touching the ground. It does need to be exterior plywood and not interior. The difference is the glue they use. Exterior plywood uses waterproof glue. It should be painted but look at the "oops" paint at Home Depot or Lowe's to save money.
For six hens two nests minimum size 12" x 12" x 12" would work. I made mine 16" cubes as 16" matched my stud spacing. That made fit-up easy.
I don't see your ventilation. In Wisconsin ventilation is important winter of summer. The reason you want ventilation in winter is that you need the moisture from their breathing, their poop, any thawed water, or anything else to escape. Moisture can lead to frostbite when it is below freezing. But in winter you don't want a breeze blowing on the chickens on the roosts. An easy way to do this is to have openings at the top so any breeze is over their heads. If you put some roof overhang just leave the top of your wall open but covered with hardware cloth to keep predators out. The overhang should keep rain and snow out.
The way your roof is sloped rainwater will flow off the roof onto the nest. You want to keep the nest dry plus would you want to collect eggs when it is raining. You might want to move the nest to a side. Think about how you are going to do your hinged door so water does not leak inside.
In Wisconsin I'd built it bigger. Having the run covered will help a lot but snow can still blow into the run from the side. My chickens are OK being out in cold weather as long as a cold wind is not blowing. There is a real good chance yours will spend a lot of time in the coop section only. The more they are crowded and the longer they are crowded the more likely they are to have behavioral problems. Where are you going to feed and water them? If it is in the coop you need room for that where they will not poop in it from the roosts. A larger coop instead of the absolute minimum will make your life easier. If you are buying new material it probably comes in 4' or 8' sections so if you use these you will have less cutting and waste. A 6' dimension isn't bad, the cut-offs may be useful for nests and such.
To save money you might buy check Craigslist to see if people are giving away materials. Or ask at a construction site if they have materials they are throwing away. Often they use material as construction aids and toss it when they are finished with it. Another possibility is to check a "habitat" recycle store to see if they have stuff. It's not just wood, hardware can be really expensive. If you can get recycled material tailor you dimensions around that.
Not sure which of those is your pop door but it should be raised high enough off the floor so they don't scratch bedding out if it. Or put an easily removable barrier at the bottom to hold the bedding in but make clean-out easy.
I strongly suggest making the run high enough you can walk in there. Since you plan to build it in sections I'd consider making the run section larger. I don't know how you are building it but it should be a lot lighter than the coop section. I think everything else has been covered.
I also like the sketch and the general plan. You have put some thought into it.
For six hens two nests minimum size 12" x 12" x 12" would work. I made mine 16" cubes as 16" matched my stud spacing. That made fit-up easy.
I don't see your ventilation. In Wisconsin ventilation is important winter of summer. The reason you want ventilation in winter is that you need the moisture from their breathing, their poop, any thawed water, or anything else to escape. Moisture can lead to frostbite when it is below freezing. But in winter you don't want a breeze blowing on the chickens on the roosts. An easy way to do this is to have openings at the top so any breeze is over their heads. If you put some roof overhang just leave the top of your wall open but covered with hardware cloth to keep predators out. The overhang should keep rain and snow out.
The way your roof is sloped rainwater will flow off the roof onto the nest. You want to keep the nest dry plus would you want to collect eggs when it is raining. You might want to move the nest to a side. Think about how you are going to do your hinged door so water does not leak inside.
In Wisconsin I'd built it bigger. Having the run covered will help a lot but snow can still blow into the run from the side. My chickens are OK being out in cold weather as long as a cold wind is not blowing. There is a real good chance yours will spend a lot of time in the coop section only. The more they are crowded and the longer they are crowded the more likely they are to have behavioral problems. Where are you going to feed and water them? If it is in the coop you need room for that where they will not poop in it from the roosts. A larger coop instead of the absolute minimum will make your life easier. If you are buying new material it probably comes in 4' or 8' sections so if you use these you will have less cutting and waste. A 6' dimension isn't bad, the cut-offs may be useful for nests and such.
To save money you might buy check Craigslist to see if people are giving away materials. Or ask at a construction site if they have materials they are throwing away. Often they use material as construction aids and toss it when they are finished with it. Another possibility is to check a "habitat" recycle store to see if they have stuff. It's not just wood, hardware can be really expensive. If you can get recycled material tailor you dimensions around that.
Not sure which of those is your pop door but it should be raised high enough off the floor so they don't scratch bedding out if it. Or put an easily removable barrier at the bottom to hold the bedding in but make clean-out easy.
I strongly suggest making the run high enough you can walk in there. Since you plan to build it in sections I'd consider making the run section larger. I don't know how you are building it but it should be a lot lighter than the coop section. I think everything else has been covered.
I also like the sketch and the general plan. You have put some thought into it.
