If you look at the options for store bought coops, they always tell you how many chickens you can put in there, and it's usually about 1 sq foot per bird, which is only 25 percent of what everyone around here would say. I really wonder what the number needs to be, and who figured it out, and if anyone has success with keeping chickens in 3 sq feet per bird instead of 4.
4/10 is just the "safe" number to use. My coop is slightly less than that, and will be closer to three than four by this summer. I expect no problems. Here's why.
A) the free range. The coop is for roosting and laying. Even in winter, they get out and stretch their legs because rarely is the entire run snowed in. They aren't confined. Confinement changes everything.
B) 4/10 matters LESS, the larger the area gets.
I think it was @aart I saw talking about it this first, but I makes a load of sense. If you have a 12 sq ft coop, and three birds in it, if you figure the birds use 1 sq ft, that leaves 9 sq ft for anthing and everything else. If you feed or water inside the coop, there's another couple feet gone. So when one bird needs to get "away" it only has 9 sq ft to get away into. That is essentially a conjoined area. Every sq ft is going to touch every other available sq ft. If that same rule is applied to an area 120 sq ft, and 30 hens, then those 30 hens have 90 sq ft of unoccupied space they can move to.
If, as you asked, you try to get birds in 3 sq ft, that area could house 40 hens. And there is still, 80 sq ft for them to move to.
If, however, you apply 3 sq ft to our first coop, you have only 6 sq ft of free space for them to try to move to.
Does that make sense?
