I have a 3-sided barn that is 12x36 that I'm considering converting to a chicken coop (partially at least). The barn is only 8 years old, used for horses originally but have gotten out of the horse business since. The basic though is to enclose one of the 12x12 stalls into a coop. The barn is about 16' at the front and planning on leaving the top couple of feet on the front and one side open for venting and just running hardware cloth around the top. I'll attach a run with some chain link fence (not great against small predators I know, but I have a couple hundred feet of it laying around just taking up space and I'm confident in the eventual coop being secure. The barn is close to my house so day time predators can be dealt with via gunshot). Basic run can be relatively large with the available chain link, and I'll cut some sections to place on the ground to slow down digging predators until I can put them down. My concerns are: How many chickens should be houses in a 12(w)x12(l)x16(h) coop? I know there is a general thought of 4' per bird indoors. Right now I have 7 birds with no real plans to greatly expand. Maybe another dozen, so we're talking 12-20 bird range. I've read threads here that suggest that too big of a coop can be a problem in cold temperatures since the birds can't warm the area? Should I plan on more birds or would I be ok? I'm fine with either really since I wouldn't mind using the space for birds since most hatchery orders are 25, but if I can give my flock plenty of room, I'm great with that also. Just looking for advice. Second concern. Bedding and odor and such. Right now, In my little 4x8 pallet coop I use a deep litter method and never smell anything from the chickens. The coop is probably 30' from my house and the new set-up will be roughly the same . My question I guess is if I end up getting say, 30 birds - what type of bedding/maintenance would you suggest to prevent odor from being a problem. Again, I'm fine with whatever works. I've only ever used a deep litter method as I've always had a small flock (never more than 8 at a time). If deep litter would continue to work, great. How is sand? Not just for litter and odor control, but also for the comfort of the birds? Does it get too cold in winter for example?
That sounds like a good plan to me! You should have no worries about cold weather getting "too cold" in Virginia. I have read that "too cold" is somewhere around minus 30F. A properly ventilated coop doesn't warm much from outdoor temps, anyway. What they need is removal of the humidity and ammonia they put out. IMO there is no such thing as "too big." The other usual recommendation here, besides the 4 sq ft indoors, is 10 sq ft outdoors. These are really estimates of how much space is likely to prevent pecking/cannibalism. Mine have a lot more, which causes no problem at all. I also use deep litter, mostly pine shavings with some hay, in a large coop with a dirt floor, and it is only cleaned out once a year. No odor. Lots of people use sand, in all climates, but keep in mind they scoop their poop frequently, which I never do. There is certainly a direct correlation between amount of space and time spent in management. Some with lots of good chicken experience will say my method is not a good thing; others will say they have used it for many years without a problem. There is certainly no single "best" method, or even a lot of agreement about the various methods. Here is a link to an excellent article on space: https://www.backyardchickens.com/a/how-much-room-do-chickens-need
Starting this soon and only expect it to take a few days. Question on ventilation. If I basically box a stall in, I'll have 2 sides that reach to the roof (outside walls). If I box in the front and other side, how much ventillation would you recommend? Barn is probably 14 feet high at a guess but can measure tomorrow. Initial thoughts are to go to about 8 feet and then the remaining area open with hardware cloth. Should I go higher? 10-12' with wood and only lave 2-4' of wire? There are no windows on the walls, but I could add them to one or both of the walls, but hoping to avoid any extra construction by allowing for the ventilation at the top (as well as keeping a relatively low number of birds - I'd be surprised if I get above a dozen or dozen and a half in the 12x12x14 (also adding a 12x~20 run).
Rule of thumb is 1 square foot of ventilation for each bird. .....but..... ...... it depends on the environment and site; climate, weather, prevailing winds and such. Since your already inside a barn that might not all come into play. You want to avoid direct drafts on the roosting area. It's always good to have a bit of ventilation down low to introduce fresh air that will then work it's way up to the majority of the ventilation well above the roosting area. Always good to have a window or two for light if nothing else.