A good chicken coop interior layout goes in this order: roosts highest, nests lower and out of the roost’s way, the pop door where the flock can reach it without a draft on the roost, vents above the birds’ heads, and clear floor for you to work. Everything else is a detail. The numbers below are the ones our 4x6, 6x8 and 8x12 walk-in floorplans use, set beside what Penn State and Oregon State publish.
None of this needs a drawing to follow, so each rule comes with the dimension and the plan that carries it.
Roosts: highest, wide enough, off the wall
Three extension sources disagree a little. Penn State says 6 inches a bird, 18 to 24 inches above the floor, a foot apart, never above 4 feet. Oregon State says 5 to 10 inches a bird on poles 2 feet up and 10 inches apart. Ohioline says 6 to 8 inches on poles 1.5 to 3 inches across. Our plans split the difference: the top of each bar is 20 inches off the floor, 11-13/16 inches from the next bar and at least 7-7/8 inches off the wall, with the bars staggered like stair treads so a hen below is not under a hen above.
The bar is a 2x4 mounted on edge, a 1-1/2 inch face up with the corners eased, because a 3-1/2 inch flat face is what our plan text avoids for footpad pressure. Keepers in hard-freeze climates lay it flat so a hen can cover her toes with her breast feathers, and our plan text says that trade is for them only. Under the bars goes a removable droppings board 24 inches deep, never wire, which is where a night’s manure lands.
Nests: lower than the roost, outside the wall
Oregon State wants a box about 12 by 12 by 12 inches, one per four hens. Penn State wants at least 12 by 12, boxes 2 feet or more off the ground and 4 feet from the roosts, with 2 inches of material and a 3 to 4 inch front lip. Our plans hang the bank on the outside of the high back wall: 17 inches deep, 14 high at the back and 10 at the front, which makes a 4 inch lip, with a hinged lid so you collect without going in. Each box comes out about 15 inches wide. Outside placement also keeps the boxes clear of the roost bars, which on a floor this small is hard to do from the inside. See the nesting box guide.
Three floorplans
| Plan | Bird floor | Rated | Nest bank, 17 in deep | Roost bars | Droppings board | Walls | Clear width |
|---|---|---|---|---|---|---|---|
| 4x6 coop | 16 sq ft | 3-4 | 2 boxes, bank 30-1/4 in (15.1 in each) | 2 x 25 in = 50 in | 27 x 24 in | 36” | 42” |
| 6x8 chicken coop | 37 sq ft | 6-9 | 3 boxes, bank 45 in (15.0 in each) | 2 x 49 in = 98 in | 51 x 24 in | 54” | 66” |
| 8x12 walk-in | 58 sq ft | 14-18 | 5 boxes, bank 74-1/2 in (14.9 in each) | 3 x 73 in = 219 in | 75 x 24 in | 76” | 90” |
The 4x6 is a reach-in with 36-inch walls and a 30 by 34 inch access panel, two boxes and two 25-inch bars. The 6x8 chicken coop has 54-inch walls, a 32 by 52 inch panel, a 45-inch bank and two 49-inch bars with a leg under each. The 8x12 walk-in has 76-inch walls, a 34 by 74 inch door on the front wall, five boxes on a 74-1/2 inch bank, three 73-inch bars with a leg at 36-1/2 inches, and a 96 by 36 inch feed room at the far end behind a stud wall that runs to the roof.
The pop door and the vents
The pop door is a 12 by 14 inch opening on the run-end wall of all three, with a ramp cut to the measured drop. On the 8x12 the sill is 22-1/4 inches above grade and the ramp about 43 inches. Put the opening on the end wall away from the walk-in door, so a draft from the door does not cross the roost. Vents go above bird height: on our shed-roof coops, a strip 5-1/2 inches deep along the top of the high back wall, plus 18 by 23 inch windows with hardware cloth on the inside. Penn State says to put openings on the side away from the prevailing wind. Sizing and the winter rule are in the ventilation guide.
Aisle width and why 8 feet
The plan data calls a coop a walk-in at 8 feet wide, 76-inch walls and a 34 by 74 inch door. The 6-foot-wide coops, including the 6x8 walk-in, are classed tall reach-in with a 32 by 70 inch access panel. The arithmetic shows why: take the clear width and subtract the 24-inch droppings board. The 8x12 has 90 inches clear, which leaves 66 inches of floor in front of the roost. A 6-foot coop has 66 clear and leaves 42. The 4x6 has 42 and leaves 18, which is an arm’s reach, not an aisle.
Where the door goes is covered in the door plans and the bars in the roost plans.