Buying or building a large chicken coop

A large coop, meant for a dozen birds or more, is a different project from a backyard kit. It is closer to a small barn. Get the layout right and daily chores take minutes. Get it wrong and you are fighting wet bedding and crowding every winter.

Space math for big flocks

The per-bird numbers do not change as a flock grows. Plan on about 4 square feet of coop floor and about 10 square feet of run per standard hen. That works out to roughly 48 square feet of coop and 120 square feet of run for 12 birds, and about 80 and 200 for 20 birds. Give each hen 8 to 10 inches of roost. Plan one nest box per 4 to 5 hens, so a flock of 20 needs four or five boxes. The pages for 12 chickens and 20 chickens show how those numbers fit into real footprints.

What makes a large coop good

• Walk-in height and a full-size door.
• Zones that make sense. Roosts in one area, nest boxes in a darker spot, feed and water near the door.
• Roosts on one level or a gentle slope, never a steep ladder.
• Electric or solar lighting, so you can check birds after dark.
• A way to split off a section for new birds, broody hens or an injured bird.

The biggest mistake with large prefab coops is buying one whose bird count assumes bantams or very tight packing. Check the floor area yourself.

Protecting a big flock

A big run is hard to fully cover, so many keepers combine a secure, roofed run with supervised free-ranging. Use 1/2 inch hardware cloth on vents and the lower run walls. Add an apron or buried skirt around the base. For a large perimeter, electric poultry netting can add another layer. Use the predator fence calculator to figure your wire needs.

Airflow at scale

Twenty birds breathe out a lot of moisture overnight. Plan generous vents up high, ideally along the ridge or on two walls for cross flow. Wet air in a big coop is the usual cause of ammonia smell and frostbite in winter.

Price and build versus buy

Large prefab coops and coop sheds commonly cost somewhere from about $2,000 to well over $5,000 depending on size and materials. Many keepers convert a shed or barn stall, which can be far cheaper. If you build, the coop planner will help you lay it out.

Common questions about large chicken coops

How many nest boxes do 20 hens need?

About four or five. Hens often share favorites, so you may see eggs in only a few boxes, but extra boxes reduce crowding.

Do large coops need electricity?

It is not required, but lights and a heated waterer base make winter chores much easier. Use outdoor-rated fixtures and keep cords away from birds.

How often should I clean a large coop?

With deep litter, many keepers add fresh bedding as needed and do a full clean-out once or twice a year. Remove wet spots right away.