I read the link at the bottom of your post Ridgerunner. Informative. So how big should I go? How many chickens should I start with? The number 20 comes to my mind, but for no particular reason. If slaughter some and am down to 15, can I just introduce more chicks to a group of mature birds? As far a roaming goes, I work half the month or less and between my wife and I, someone is usually always more during the day. So they'll be able to leave the coop/run most days. In the winter as well, which makes me think... will they forage well in the winter? After all, there's still a lot of evergreens and other brush around. Just a thought.
You earlier said you were looking at eating 25 to 30 chickens a year. That's not many. Roosters do make noise and in some communities there are rules about keeping chickens. They may be banned or you may not be allowed a rooster. Numbers may be limited. If you are worried about noise from a rooster and your neighbors it may be worth checking out what, if any, restrictions you legally have. It sounds like you have pretty close neighbors.
So let's assume you are not going to hatch any chicks, you are going to buy baby chicks. I don't know how things work in Canada, what restrictions you may have on that. What times of the year are chicks available? Are their minimum limits? You may need to mail order them (they are shipped in the mail) or maybe you can get them from that feed store at certain times of the year. How often each year do you want to raise chicks which translates to how many each time? From what I can tell, you are still uncertain if you are going to go dual purpose or specialty layer/meat birds.
They will not get much forage in the snow, especially how deep I think yours will be. When they first see snow chickens are afraid of it, but normally after time they will get used to it and may go walking in it. If you have grass and weeds sticking up out of it they are more likely to go roaming, but you will wind up buying almost all of the food they eat for several months.
I assume Canadian building materials are the same dimensions as here in the States, standard 4' and 8' dimensions. Since you don't know which direction you are going and they will be coop-bound a lot of the time, I'd suggest you go with something like an 8' x 12' to take advantage of standard building material sizes. An 8' x 8' would probably work but the extra 4' length gives you a lot more flexibility in how you manage them. It gives them a lot of room in winter and you can partition off sections as you need them. You can build in storage. Since you are planning on electricity out there you can build in a brooder and raise the chicks out there. If you ultimately decide you don't want to fool with chickens, you have a great storage building.
If you run electricity out there I suggest a breaker box in the building. There are advantages in having lights, heaters, and just general plug-ins for electrical tools on different circuits out there. As dark as you are going to be for half the year I'd want lights so I can see what I'm doing.
A lot of us integrate chicks with the flock a lot. That's another very long post though so I'll skip it for now. But integration is another reason to have lots of room, that's another reason I suggest going big.
Since you are not going to be hatching I'd suggest starting with the specialty meat/laying chickens. Get some and see how it goes. I think that will suite you best, but you can always try dual purpose later if you wish.
