A chicken coop only has to do five things — keep predators out, keep weather out, move air through, give hens a place to roost and a place to lay, and let you clean it without crawling. Every coop that fails, fails at one of those five; every backyard palace and every converted shed that succeeds, succeeds at all of them. This guide is the design brief I’d hand any first-time builder: the requirements that are non-negotiable, the decisions that are yours, the build order, and the mistakes that get built in on day one and cursed for years.
Quick Facts
| Space | 3-4 sq ft per bird inside + 8-10 sq ft per bird in the run — then build bigger |
| The #1 material rule | Hardware cloth (½”) on every opening — chicken wire stops nothing with teeth |
| Ventilation | Openings high above roost level, drafts blocked AT roost level — even in winter |
| Inside | Roosts higher than nest boxes; one box per 3-4 hens |
| For you | A human door or full-open roof/wall — if cleaning is hard, it won’t happen |
| Site | High, dry ground with summer shade; never the low spot that puddles |
The Five Requirements (Non-Negotiable)
1. Predator-proof. Everything eats chicken — raccoons, dogs, hawks, foxes, weasels that fit through an egg-sized gap, rats that tunnel. The standards: ½-inch hardware cloth screwed down with washers on every window, vent, and gap (chicken wire keeps chickens in; it does not keep predators out — a raccoon opens it like a bag of chips); two-step or carabiner latches, because raccoons genuinely work simple ones; and a dig barrier — hardware cloth apron laid a foot outward around the perimeter, or buried skirt — because most night raiders arrive under the wall, not over it. The deep version is in the coop security guide.
2. Dry. Moisture, not cold, is what hurts chickens — damp bedding brews ammonia and coccidia, damp air frostbites combs. Sound roof, no leaks, and site the coop on high ground (the low corner of the yard that puddles in rain is where coops go to rot).
3. Ventilated — which is not the same as drafty. A flock exhales a surprising amount of water vapor and ammonia every night, and it has to leave the building. The rule that resolves the winter panic: openings up high (above head height at the roost — under the eaves is classic), solid walls at roost level so no wind hits sleeping birds. You can have a coop that’s both draft-free and airy; you cannot have a sealed coop that’s healthy. Never build vents you can’t leave open in January.
4. Furnished right inside. Roosts — 8-12 inches of 2×4 (wide face up) per bird, mounted higher than the nest boxes, with a droppings board beneath. Nest boxes — one per 3-4 hens, roughly a 12-inch cube, in the darkest corner, with a sloped roof so nobody sleeps on top. Feeder and waterer stations that can’t tip or foul.
5. Cleanable by an adult human. The requirement everyone under-builds: a full-size door, a hinged roof, or a removable wall — some way to reach every corner with a rake standing more or less upright. A coop you have to crawl into is a coop that gets cleaned twice a year instead of weekly, and the whole cleaning routine depends on access being easy.
The Decisions That Are Yours
Size: do the math for the flock you’ll end up with, not the one you’re starting with — chicken math is real, everyone adds birds. 3-4 square feet per bird inside, 8-10 in the run; more space is the single cheapest health and behavior insurance you can build, and crowding is the root of half the pecking and disease problems on this site.
Fixed or mobile: a stationary coop can be bigger and stouter; a chicken tractor (a moveable coop-and-run) gives the flock fresh ground and spreads the manure for you, at the cost of size and predator-stoutness. Small flock, big yard? A tractor is worth a look.
Floor: raised wooden floor (dry, rat-discouraging, adds under-coop shade) versus dirt floor with a buried wire skirt (cheap, works with deep litter). Both succeed; a raised floor is the beginner-friendlier call.
Walk-in or reach-in: if you can spare the footprint, a walk-in shed-style coop wins on every count that matters daily — cleaning, egg collection, catching a bird, your back.
Scrounge or buy materials: coops are the great pallet-and-salvage project, and chickens don’t care about paint. Spend the real money where it counts: hardware cloth, hinges and latches, and a roof that doesn’t leak. (If building isn’t your thing at all, buying a decent small coop is honorable — just apply this same checklist to whatever you buy, especially the space claims.)
A Sensible Build Order
- Site it: high ground, summer afternoon shade, close enough to the house that winter chores actually happen, and check your setback rules first (the legal step).
- Frame the box — simple shed geometry beats clever; a single-slope roof is the beginner’s friend.
- Roof and walls on, gaps planned for ventilation up high.
- Hardware-cloth every opening before anything else goes inside — screwed with washers, not stapled.
- Hang the doors — pop door for birds, human door for you — with raccoon-grade latches.
- Furnish: roosts high, boxes low, droppings board under the bar.
- Run and dig-apron around it.
- Move-in week: keep the flock shut in the coop for a few days so it imprints as home — after that they’ll put themselves to bed every dusk for life.
The Mistakes That Get Built In
Chicken wire where hardware cloth belonged (the classic, and the fatal one) · the coop sized for the first flock (see chicken math) · vents that seal shut “for winter” (ammonia and frostbite factory) · nest boxes mounted level with or above the roosts (enjoy sleeping hens fouling the nests — the roost rule) · no droppings board · doors that open inward against bedding buildup · siting in the wet low spot · and skipping the dig apron because the ground “seems hard.” Every one of these is cheap to do right on build day and miserable to retrofit.
Real Questions from Real Keepers
How big should I build for 6 hens?
Roughly 18-24 square feet of coop (a 4×6 footprint) plus a 48-60 square-foot run — and if you have the room, build the 4×8 instead, because flock six becomes flock ten with remarkable regularity.
Can I convert a shed or playhouse instead of building from scratch?
Absolutely — a sound shed is a head start on the hardest parts (frame, roof, human door). Your job becomes ventilation up high, hardware cloth on every opening, roosts-above-boxes inside, and a run attached. Some of the best coops I’ve seen started as something else.
Do I need to insulate or heat the coop?
In most climates, neither — chickens wear down jackets and handle cold far better than damp. Dry, draft-free at the roost, and ventilated beats insulated-and-sealed every time. Heat lamps in coops are also a genuine fire risk; skip them outside of true extremes.
What’s the best floor covering?
Pine shavings over whatever floor you built, deep enough to absorb (a few inches, more in winter if you’re running deep litter). Never cedar, never anything that stays damp — the details are in the bedding section of the cleaning guide.
Is it cheaper to build or buy?
A scrounged build is the cheapest path and a lumber-store build usually lands near the price of a mid-tier prefab — but the built coop will be roomier and stouter than the prefab at the same money. Buy for convenience, build for value; either way, judge it with the five requirements at the top of this page.
By Brad Wynne. I’ve kept backyard chickens and answered readers’ health questions on this site since 2009 — every question above came from a real keeper with a real bird.