2 layer coop?

Unless you are going to free range, that's not nearly large enough. You want about four sq ft per hen minimum in the coop, and about ten sq ft MINIMUM in the run. You have 64 sq feet of coop(definately large enough) and run, which should be large enough only for six hens to be happy. Crowd them in too much, and you will have health and behavior problems.

 

4 square feet of coop per bird is a good minimum. Mine have a huge run and free range in the afternoon, but it still seems a bit crowded at 6 square feet per bird on days when they hang out inside. 16x4 gives you 64 square feet which would be fine for 16 birds, but consider that a rectangle has less area than a square. The closer you get to a square, the more you have maximized your area for the amount of perimeter you have put up.

16'x4' would have a 40-foot perimeter. It gives you 64 square feet, and works really well with 8' sheets of board.

But consider that a 10'x10' coop - still 40-foot perimeter - is 100 square feet! That would be room for 25 birds with 4 square foot a piece, but would cost you a similar amount in materials.

You could also do an 8'x12' - still 40-foot perimeter - which would be 96 square feet, enough for 24 birds with 4 square feet apiece.

Of course, you might be limited by area in your yard. But if not, consider a more square coop to maximize your floor space!

Good luck with whatever you decide! I'm sure it will be awesome!

Oh - and