4x4 Starter Chicken Coop with Run Plans

Four 4x4 posts cut to 64-3/4" carry the structure from grade to the top plate. Setting the floor 18" up keeps the frame out of ground moisture and hands the flock the shaded space underneath.

The base ring ties the four posts into a rigid square at grade. Use the 4-inch screws here — this joint carries the racking load for the life of the coop.

Joists sit 18" above grade on 16" centres, running the short direction across 45" in 2x6, with the rim doubled on all four sides. At 45" the 2x6 joists span well inside the 8 ft 4 in that AWC DCA6 Table 2 allows at 16-inch centres, so no intermediate girder is needed. Crown every joist up before you fasten it. Fixing the floor frame to the posts. This is the joint everything above stands on and it is the one most plans leave to guesswork. Build the rim rectangle first, square it to the diagonals, then drop it over the four posts so the rim sits ON the base ring and CLOSES the outside face of each post. Fasten each corner with two 4in structural screws driven through the rim into the post, one 1-1/2in down from the top of the rim and one 1-1/2in up from the bottom, offset from each other so they are not in the same grain line. Eight screws in total, four corners. Predrill — a 4in screw close to the end of a 2x6 will split it otherwise.

Deck the floor in 3/4" plywood, notched 3-1/2" square at each corner so it drops cleanly around the posts. Fasten with 1-1/2 inch screws every 8 inches on the joists.

Every wall is framed FLAT ON THE DECK and then stood up. That is the whole trick: you are working on a level surface, gravity holds the parts where you put them, and you can push the frame square before a single screw goes in. Studs run 16" on centre so 4-foot sheet goods break on a stud. Build order matters. Front wall, back wall, then the two end walls. The long walls go up first and get braced to the deck; the end walls then drop between them and lock the box square. If you stand a short wall first it has nothing to brace against. Every wall gets three plates: a bottom plate, a top plate, and a cap plate over the top. The cap plate is not a second top plate for strength — it is there to LAP the corner. Hold the cap plate back 1-1/2" at one end of each long wall and run it 1-1/2" long at the other, so when the end walls go in the caps interlock and tie the four walls into one ring. A butt joint at all four corners is a box that racks. Cut the bottom plate CONTINUOUS through every door opening. Frame it, stand it, brace it, and only then saw the plate out of the doorway with a handsaw. It is what keeps the wall square while you move it.

The wall you face when you walk up to the coop. It carries the door and most of the glazing. Plate length 41". Openings: access panel 30" x 34". 11 pieces in this wall. Every dimension on the drawing runs from the LEFT end of the plate to a stud CENTRE. Mark the whole plate out before you cut anything — lay the bottom and top plate side by side, square across both at once, and you cannot get the two out of step.

The nest bank hangs on the outside of this wall and the vent strip runs along the top of it, so keep the top two stud bays clear. Plate length 41". Openings: nest bank opening 30-1/4" x 13". 18 pieces in this wall. Every dimension on the drawing runs from the LEFT end of the plate to a stud CENTRE. Mark the whole plate out before you cut anything — lay the bottom and top plate side by side, square across both at once, and you cannot get the two out of step.

The run attaches to this wall, and the pop door passes through it. Plate length 41". Openings: pop door 12" x 14". 15 pieces in this wall. Every dimension on the drawing runs from the LEFT end of the plate to a stud CENTRE. Mark the whole plate out before you cut anything — lay the bottom and top plate side by side, square across both at once, and you cannot get the two out of step.

The far end. Fixed wall with a window. Plate length 41". Openings: window 18" x 23". 15 pieces in this wall. Every dimension on the drawing runs from the LEFT end of the plate to a stud CENTRE. Mark the whole plate out before you cut anything — lay the bottom and top plate side by side, square across both at once, and you cannot get the two out of step.

A 12:12 gable — the rise equals the run, so every rafter is cut at 45 degrees and the ridge lands 24" above the top plate. Cut one rafter, test-fit it, then use it as the template for the rest. Every opposing rafter pair is tied. A pitched roof pushes outward at the eaves, and without a tie resisting that thrust the walls slowly spread and the ridge drops — the code (IRC R802.3) requires either continuous rafter ties or an engineered ridge beam, and a plain ridge board on untied rafters is neither. The ties sit at top-plate level, so they double as the framing you hang a droppings board from.

3/4" plywood over the rafters, then corrugated metal sheets. Metal over shingles because it sheds snow, lasts decades and never needs a tear-off. Lap the sheets one full corrugation.

Lap siding in 9-foot courses, starting from a level chalk line at the bottom and working up. Each course laps the one below by 1 inch. Leave the window and door openings proud and trim after.

Every opening you framed in step 5 now gets something to close it. Cut each slab a quarter inch smaller than its rough opening on all four sides — 3/4in plywood swells in the wet and a door cut to the exact opening size will bind by November. Access panel on the front wall: slab 29-1/2" x 33-1/2" in a 30" x 34" opening — a 1/4in gap all round. 2 hinges, out, hinged on the left as you face it from outside. Pop door on the left end wall (run end): slab 11-1/2" x 13-1/2" in a 12" x 14" opening — a 1/4in gap all round. 2 hinges, out, hinged on the left as you face it from outside. Every plywood door over 30in tall gets a Z-brace on the back: a rail top and bottom and one diagonal running from the bottom hinge corner up to the top latch corner. That diagonal is in compression and it is the only thing stopping the door sagging into a parallelogram. Run it the wrong way and it does nothing. Hinge side and swing. All doors here swing OUT, hinged on the left as you face them from outside. Out, because a door that opens inward sweeps the bedding and gets blocked by it; left, so every latch on the coop is in the same place and you are not hunting for it in the dark with an armful of feed.

An exterior nest bank 30-1/4" long and 17 inches deep, hung off the side wall with a hinged lid. 2 compartments — one per three to four hens. Collecting eggs from outside means you never disturb a sitting bird.

The pop door is a 12 x 10 inch plywood panel on a hinge with a latch, opening onto a cleated ramp down into the run. At 24-1/4" of drop the ramp wants to be about 46-1/16" long with cleats every 4 inches.

The 4 ft x 4 ft screened run frames off the coop wall, 62" tall. 2 posts a side on roughly 4-foot centres, with a top rail and a mid rail so the hardware cloth has something to fasten to at every course. Set the run posts the same way you set the coop posts in step 1 — on the same pier blocks, at the same height, checked with the same string line. A run on a different footing system than the coop it hangs off will move against it and open a gap at the joint, which is exactly where a predator starts. Fixing the run to the coop: the two run rails that meet the coop are lag-bolted into the corner posts of the run-end wall, not screwed into siding. Two 3/8in x 4in lag bolts per rail, drilled with a 1/4in pilot, one 3in above the rail's bottom edge and one 3in below its top. Siding is a skin; it holds nothing.

The step that decides whether you still have a flock in two years. Quarter-inch hardware cloth over every opening, screwed through fender washers rather than only stapled. Quarter-inch, not half-inch: a least weasel squeezes through anything 1/4 inch or larger (Univ. of Kentucky Extension ID-245), and half-inch mesh — while genuinely raccoon-proof — does not stop weasels, mink or snakes. Chicken wire stops nothing: a raccoon reaches straight through the hexagonal gaps. Bury a 12-inch apron down and out around the whole run perimeter (12 inches is confirmed by three separate extension services). The windows get cloth too. An open 18 x 23 window is a hole a raccoon walks through, and it is the ventilation you rely on in summer, so it has to stay open at night. Staple a panel of cloth to the INSIDE of every window opening before the unit goes in — behind the glazing, not over it, so the window still shuts on a clean frame. Same for the continuous vent strip along the top of the back wall and the nest-bank opening.

4 birds NEED 40 inches of perch at 10 inches each, comfortably above the 6-inch minimum the extension services set. The cut list below BUILDS 50 inches — 2 bars at 25". Those are two different numbers and this plan states both, because a plan that prints the requirement and calls it the built total is contradicting its own cut table. Use a rounded or slightly flattened bearing surface 1 to 2 inches across rather than a thin dowel or a full 3-1/2 inch flat face: it spreads footpad pressure and lowers bumblefoot risk. Set the bars 18 to 24 inches off the floor, 10 to 12 inches apart, and at least 8 inches off the wall. Stagger them like stair treads rather than stacking them, so the birds underneath do not get rained on. No bar sits over a nest box. Directly beneath the bars goes a removable droppings board — birds put out most of a night's manure while roosting, and catching it on a board you slide out and scrape turns the daily clean into a two-minute job. Never use wire for this: droppings stick to mesh and it becomes impossible to clean.