What Should Be Inside a Chicken Coop? The 6 Fittings

A chicken coop needs six things inside it: a roost, nest boxes, litter, ventilation, feed and water, and light. Penn State Extension puts the roost 18 to 24 inches above the floor and at least four feet away from the nests, and calls for two nests for the first four hens, then one more for every four hens after that. Which of the six come fitted varies by model, so read the spec table before you buy anything separately — you can compare them across the coops we sell. One number you will not find on a listing, ours included: how long the roost bar is.

Every figure below is quoted from a named cooperative-extension publication, linked at the bottom with the date we read it.

What should be inside a chicken coop?

Six fittings: a roost to sleep on, nest boxes to lay in, litter on the floor, ventilation above head height, a feeder and a waterer, and — only if you want eggs through winter — a light. Everything else is decoration.

That list is shorter than most people expect, and the order matters. Hens sleep on the roost and lay in the boxes, and if the two sit too close together they will do both in the boxes. Penn State Extension is blunt about it: keep the roosts away from the nesting areas, or "this will quickly contaminate your nesting boxes and increase egg breakage and dirty eggs."

So the interior is a layout, not a shopping list. Three of the six fittings have to be positioned relative to each other before anything gets screwed down.

The coop and the run are two different rooms

Most "what goes inside" lists mix them up. The coop is the enclosed box the hens sleep and lay in — roost, nest boxes and litter go there. The run is the fenced area they spend the day in, and it needs shade, a dust-bathing patch and space, not bedding.

The distinction decides half the answers below. Litter depth applies to the coop floor, not the run. Ventilation is a coop problem, since the run is already open air. And on a coop that moves the run has no floor at all — the birds stand on grass and you shift the frame to a fresh patch, which is the whole argument for moving one.

6 fittings, and the numbers behind each one

Every fitting has a published figure attached to it, and those figures come from cooperative-extension services rather than from manufacturers. The table is the whole answer in one block. The sections after it explain the two places where the published numbers disagree with each other.

Read the ventilation row again, because it is the one that surprises people. There is no number. That is not an oversight in the table.

How much roost space per hen? Three services, three answers

Penn State Extension says six inches of perch per standard hen. Virginia Cooperative Extension says eight to ten. UNH Extension says a full linear foot. For six hens that is a roost between 36 and 72 inches long, depending which land-grant university you read first.

Nobody is wrong. They are describing different birds in different climates: hens crowd together on the bar in winter and spread out in July, and a Rhode Island Red takes up more bar than a bantam. Virginia's own publication says the quiet part out loud — "There is very little research on space requirements for small-scale poultry housing."

Our view: build or buy to the middle figure, eight to ten inches a bird, and treat six as the floor rather than the target. The cost of getting it wrong is not theoretical. Hens compete for the highest bar and the bird at the bottom of the pecking order gets pushed off. She sleeps in a nest box instead — the exact outcome Penn State's four-foot rule exists to prevent — and you find it next morning in the eggs.

If the coop is too narrow for a single long bar, add a second one rather than stretching the first. Penn State spaces roosts a foot apart, and two 30-inch bars give the same perch as one 60-inch bar in half the width. Bigger flocks are where this bites hardest, which is worth knowing before you size up to a large coop.

Here is the part no listing solves for you. Some coop listings state how many perches are inside. None states how long the perches are — not the ones we carry, and not the ones we have read elsewhere. So the six-to-twelve-inch rule cannot be checked against any product page in this market. If you tell us the coop and the flock, we will measure the bar against the manufacturer's own drawing and confirm it before you order.

Six free coop plans, three of them moveable — every sheet dimensioned. SEND ME THE PLANS

What to put in a chicken coop floor

Litter, and enough of it. UNH Extension recommends fresh wood shavings or sawdust six to eight inches deep. What sits underneath the litter matters less than how deep the litter is and how easily you can shovel it out on a wet Sunday in November.

Coop floors come in four constructions, and each changes the litter job rather than removing it:

• Solid timber floor. Warm, cheap, absorbs moisture. Needs the full 6–8 inches of shavings and a change-out when it packs down.
• Pull-out droppings tray. A metal or plastic tray under the roost that slides out. Most coops we carry have one, and it makes the biggest difference to how long a clean takes.
• Wire or slatted floor. Droppings fall through. Less litter to manage, colder underfoot, hard on feet if the mesh is wrong.
• Open to grass. No floor at all. The birds stand on the ground and you move the frame instead of cleaning it, which is the distinction to check across coops built to move.

If you would rather build up than muck out, University of Minnesota Extension describes the deep-litter method: start with about four inches of bedding, add until it is ten inches deep by winter, then carry on to twelve or fifteen. It composts in place and gives off a little warmth. It also needs more ventilation, not less.

One rule for every floor: dry beats warm. Wet litter is where ammonia comes from, and ammonia is a respiratory problem before it is a smell.

How much ventilation does a chicken coop need?

Nobody publishes a number. Penn State Extension's requirement is "ample air movement without a draft," and its test is a symptom rather than a measurement: dampness and ammonia build-up mean there is not enough ventilation for the birds in the coop.

We went looking for the rule that circulates on hobby forums — one square foot of vent per ten square feet of floor — and did not find it in any extension publication linked below. That does not make it wrong. It does mean it is not extension guidance and should not be quoted as though it were.

What Penn State does specify is the geometry:

• On a small coop, windows or vents on one side usually provide plenty of air.
• Never put a vent directly over the perching area, or the birds sleep in a draft.
• Put openings on the side away from prevailing winds, and angle inlets upward so incoming air mixes with the warm dry air above.
• Ventilate and insulate together. One without the other puts moisture on the walls in cold weather.

The winter instinct is to shut everything and keep the hens warm, and it is the wrong instinct. Penn State's line is worth keeping: "Poultry can handle cold very well if they are dry." Cool and humid causes health problems; cold on its own does not.

Which makes the next fact awkward for the whole market, us included. No coop listing states a ventilation opening in square inches — not the ones we carry, and none we have found elsewhere. The most detailed in our range gives a vent type: top louvered vents plus a hinged, adjustable side window. Another gives its openable window as 15 by 2.8 inches, which is 42 square inches. That is not enough to compare two coops on air, so if ventilation is your deciding factor, ask us and we will get the opening dimensions from the manufacturer before you order.

Setting up the coop before the hens arrive

Order of operations matters more than speed. Fit the roost before the nest boxes, because Penn State Extension wants at least four feet between them, and wherever the bar ends up decides where the boxes are allowed to go.

Step 1 — Site it and level it

Penn State puts coops on high, well-drained ground and faces the front and windows south, so sun warms and dries the coop and the soil. A coop on a low spot is a wet coop, and wet is the thing you are managing all winter.

Step 2 — Fit the roost

18 to 24 inches up, bars a foot apart, never higher than four feet. Round the edges: a bar the hens grip badly is a bar they abandon for the nest boxes.

Step 3 — Hang the nest boxes low, dark and far from the bar

Two feet off the ground, four feet from the roosts, in a dim corner away from bright windows and traffic. The three-to-four-inch front lip keeps the material in and the eggs whole.

Step 4 — Lay the litter

Six to eight inches of shavings on the coop floor, two inches in each nest box. Penn State names pine shavings as the preferred nesting material.

Step 5 — Set feed and water at back height

Three inches of feeder space a bird, top lip level with the bird's back so they cannot scratch it full of shavings. Penn State puts the waterer out in the run where possible, which keeps that humidity out of the coop.

Step 6 — Run it empty for a day

Watch where rain gets in, where the light falls at dusk and whether the door latches when the wood swells. Every fault is cheaper to fix before there are hens standing in it.

Check the listing for these before you buy

Five fields decide whether a coop arrives ready to use or arrives needing a trip to the hardware store. Three are usually stated. Two are almost never stated, and they are the two that matter most.

Nest boxes are the fitting listings count most often — and they are also the only fitting you can see in a photograph. The pattern holds in both directions. One 76-inch metal-frame coop in our range states six nesting boxes for three to four hens, where Penn State's rule would call for two. Boxes photograph well, so they get counted and sometimes over-supplied. Perch length and vent area do not photograph at all, so they go unstated.

That is the market, not one manufacturer. It is why we publish the fittings and dimensions a manufacturer states, and confirm the ones it leaves out. If you are comparing models, the fittings sit in the spec table on each coop with an attached run, and the flock-size arithmetic is in our coop sizing guide.

What we'd change about every coop listing we've read

One line: state the roost length in inches. It is the number that decides how many hens actually fit at night, and everybody quotes floor area instead, because floor area is easy to measure and easy to flatter.

Floor area tells you whether the birds fit standing up. Roost length tells you whether they fit lying down, and hens spend more hours on the bar than anywhere else. A coop advertised for six hens with a 30-inch bar is a five-hen coop by Penn State's figure, a three-hen coop by Virginia's, and a two-and-a-half-hen coop by UNH's. Nothing on the page tells you that, and the hens tell you three weeks later by sleeping in the nest boxes.

Second: give the vent opening in square inches instead of calling it "well ventilated". Two coops can both be well ventilated and differ by a factor of four.

Until listings do either, the workaround is boring and it works — get the interior dimensions before you buy, not after. That holds whether you buy from us or draw your own from a plan.

Frequently asked questions

Why does my chicken coop smell like ammonia?

Ammonia means the litter is wet and the air is not moving. Penn State Extension treats it as a diagnostic rather than a nuisance: dampness and ammonia build-up are the sign that there is not enough ventilation for the number of birds in the coop. Deal with the moisture first — strip the wet litter, check the roof and the waterer for leaks, then open an inlet on the side away from the wind.

Where to place nesting boxes in chicken coop?

Low, dark, and well away from the roost. Penn State Extension puts nests at least two feet off the ground and at least four feet from the roosts, in a dim secluded spot, never opposite a bright window or beside a high-traffic doorway. The four-foot gap is not fussiness — it is what stops hens sleeping in the boxes, which is what makes eggs dirty and cracked.

Should I put a light in my chicken coop?

Only if you want eggs through winter. Hens need 12 to 14 hours of light a day to keep laying, according to University of Minnesota Extension. Penn State Extension calls for one low-intensity bulb, 40 watts or less, at ceiling height, and notes that a bird needs only one foot-candle to sustain year-round production. A light is optional. Ventilation and a dry floor are not.

Can I use pine shavings in my chicken coop?

Yes. Penn State Extension names pine shavings as the preferred nesting material and asks for about two inches of clean dry material kept in each box at all times. For the coop floor rather than the boxes, UNH Extension recommends fresh wood shavings or sawdust six to eight inches deep. The material matters less than keeping it dry — wet shavings are where the ammonia starts.

Should I paint the inside of my chicken coop?

Extension guidance does not ask for paint. Penn State Extension's requirement is that the coop be built so every area is easy to reach, clean and disinfect, and a sealed wipeable surface meets that where bare rough timber does not. If you do paint, let it cure completely before the hens go in, and make sure they cannot pick at peeling coating or at exposed insulation.

Written by the Moveable Chicken Coop Team Interior fittings are the half of a coop nobody photographs, so we read the manufacturer's documentation and publish the fittings and dimensions it states, next to the extension figure they should be checked against. Where a fitting is described in words rather than inches, ask us and we will get the measurement before you order. More about how we choose coops → /pages/about

Last reviewed: 28 July 2026

Sources

1. Penn State Extension, "Small Scale Poultry Housing", Gregory P. Martin and Phillip Clauer, updated 25 June 2026 — accessed 28 July 2026
2. Virginia Cooperative Extension, "Small-scale Poultry Housing", publication 2902-1092 — accessed 28 July 2026
3. University of New Hampshire Extension, "Producing Your Own Eggs" — accessed 28 July 2026
4. University of Minnesota Extension, "Raising chickens for eggs" — accessed 28 July 2026
5. Stated interior fittings and dimensions of the coops in our range: our own catalogue, read 28 July 2026.

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