Some design points for a coop in Vermont for 4 chickens.
Why do you want chickens? What are your goals for them? Eggs, pets, bug patrol, show? I sure hope you aren’t thinking of meat or breeding them, not with just four. Think about your goals for a bit, that might help clarify a few things, I think it’s a basic starting point. And it will help you a lot on breed selection.
The main thing in all of this is to make it more convenient for you. That can determine if it is a pleasurable experience or a chore. People worry about what is good for the chickens. If it is good for you it is probably good for them. You are the most important piece of this.
In Vermont you will have really pleasant summers and some pretty cold winters with a lot of snow. Heat is more dangerous to chickens than cold due to their down coats. You may see a few hot days, but it’s not likely you will have temperatures in the upper 90’s or higher for weeks on end. In summer they need shade and good ventilation, high and low. Your summers should not be that challenging.
In winter you have two considerations as far as cold. They need to remain dry and they need protection from the wind. The moisture I’m most concerned about is from their breathing, their poop, and maybe a thawed water dish. If the moisture in the coop gets too high they become susceptible to frost bite. Good ventilation gets rid of that moisture. If you build a tight coop so there is no ventilation, they can get frost bite when it is not much below freezing. With good ventilation they can handle whatever your winter throws at them. You do not need to heat the coop. The other thing they need is to be able to get out of a direct wind. Don’t build a coop that becomes a wind tunnel. You may ask how you can manage both. There are different building techniques, but for four chickens the easiest way is probably to have all winter ventilation over their heads when they are on the roosts. Lots of ventilation is good but if it is high enough any breezes will be over their heads. If you are going for cute you might consider a design that uses a cupola. Another good method is to have roof overhang and leave the tops of the walls open for good ventilation, or do both.
Another issue is your snow. Chickens don’t like change. If they wake up to a white world they are not likely to go out in it for a few days. After a few days mine will build up the courage to go outside. It’s not the snow being cold they dislike, it’s the change. They are worse than old fogeys like me about change. Why this is so important is that if you crowd them you can have behavioral problems. If they are stuck in a tiny coop for days on end they can start to get on each other’s nerves. You don’t want that, it can get really ugly. The ways to combat that are to either make your coop bigger than the absolute minimum or put a roof on your run and block off the sides so snow doesn’t cover the run. They don’t like a strong cold wind hitting them either so you need some wind protection. Some people go out and shovel the run so the chickens will use it but that’s too much work.
The three most important things about deciding where to build a coop are location, location and location. You absolutely want to avoid a low spot where water collects and it stays wet. That leads to disease and it stinks. What you want is where water drains away from it. If you don’t have such a place, I suggest you put the base of your coop/run down and fill it with a few inches of dirt so water drains away from it. Slope all you roofs so water runs away from the coop/run, don’t put extra water in there. Maybe use berms or swales to deflect rainwater run-off.
One huge health issue that can prove fatal are predators. Even if you are in the middle of town you will have many potential things that want to eat chickens. These things can dig, jump, climb, or fly. Even in suburbia you probably have a lot more raccoons, possum, skunk, hawks, owls, fox, bobcat, or coyote than you’d ever expect. I envision a small covered run with a roof on top and an apron around the bottom.
You need to be able to access every part of your coop and run. Make your run tall enough that you can walk in it without bending over or banging your head. Have sufficient doors and such so you can open up the coop enough to get to everywhere inside. Think about how you are going to keep the chickens from getting away when you have those open. Maybe a way to lock them in the run only? If it is elevated, and I think you will probably go that way, include the bottom of the coop as part of the run, that’s good shade and maybe a dry place to hang food. But make it high enough so you can reach under there if you need to. For cleaning out bedding, being able to rake everything into a wheelbarrow can be really handy.
They are going to poop a lot. You don’t want that to build up. How are you going to dispose of that? The weekly garbage? You might want to consider composting it. Something to think about.
At the top of this page, you will probably see an “articles” tab. Open that and you will see coops. There are a lot of different coops in there, most with enough plans so you can build them. Pick one you like. The absolute minimum I’d go is 4’ x 4’. A 4x6 or even 4x8 would be better, even just for 4 hens. You won’t find people complaining about having too much room but you see disasters for not having enough. I would not go any bigger than 4x8 for a coop you cannot walk into, it’s too hard to reach everywhere inside.
Good luck with it, you will come up with something that works.