A chicken pen is a fenced outdoor enclosure that lets your birds forage and exercise while protecting them from predators

A chicken pen—also called a run or yard—is a separate structure from the coop itself. While the coop is where chickens roost and lay eggs at night, the pen is where they spend daylight hours scratching, dust-bathing, and eating bugs and grass. A pen keeps birds contained so they don't wander into gardens or neighbors' yards, and it protects them from hawks, foxes, and other predators while they're outside.

The basic structure is a frame made from wood or metal, covered with wire mesh, and set on the ground. You can build a fixed pen that stays in one spot, or a mobile pen you move daily to give chickens fresh ground. Most backyard setups use wood frames with hardware cloth (a sturdy wire mesh) stapled to the frame, with an open or covered top depending on your predator risk and climate.

Key Takeaways

  • A pen needs hardware cloth (not chicken wire) on all sides and the bottom to stop predators from digging or squeezing through.
  • The frame can be built from 2-by-2 or 2-by-4 lumber, with corner posts and horizontal supports to keep it rigid.
  • A covered top protects against hawks and heavy rain, and a buried or buried-and-bent perimeter stops digging predators.
  • Mobile pens let you move birds to fresh ground every few days, which reduces disease and parasite buildup.
  • Proper ventilation and shade are essential so birds don't overheat on warm days.

Choose between a fixed pen and a mobile pen based on your space and time

A fixed pen stays in one location year-round. It's easier to build because you don't have to move it, and you can make it larger and more elaborate. The downside is that the ground underneath becomes bare and muddy, parasites and disease can build up in one spot, and you have to clean it more often. A fixed pen works well if you have plenty of space and don't mind regular maintenance.

A mobile pen (sometimes called a tractor or ark) is moved to a new patch of grass every one to three days. This gives chickens fresh forage, spreads their manure across your yard, and prevents parasite and disease buildup. Mobile pens are smaller and lighter, but you have to move them regularly—which takes time and physical effort. They work best if you have a smaller flock (four to eight birds) and the time to move the pen every other day.

Most backyard keepers start with a fixed pen and add a mobile pen later if they want the flexibility. You can also build both: a large fixed pen for bad weather and a mobile pen for good weather.

Build the frame from pressure-treated lumber or metal conduit

The frame is the skeleton of your pen. For a fixed pen, use 2-by-4 lumber for the perimeter and 2-by-2 for internal supports. For a mobile pen, use 2-by-2 throughout to keep weight down. Pressure-treated lumber resists rot and lasts longer than untreated wood, though some keepers prefer untreated wood if they're concerned about chemical leaching into soil where chickens scratch.

Lay out the frame on the ground and measure diagonally corner to corner—both diagonals should be equal, which means your corners are square. Cut and attach corner posts using 3-inch exterior wood screws or bolts. Add horizontal supports every 2 to 3 feet along the sides and top to prevent the frame from racking (twisting out of square). For a mobile pen, add handles or wheels so you can move it without straining your back.

If you prefer metal, electrical conduit (1-inch diameter) is lightweight and won't rot, though it's more expensive and requires welding or special connectors. Most home builders stick with wood because it's cheaper and easier to work with hand tools.

Cover all sides and the bottom with hardware cloth, not chicken wire

Hardware cloth is a welded steel mesh with small square holes (usually 1/2 inch). Chicken wire is a lighter, hexagonal mesh that predators can tear through or push aside. Use hardware cloth on all sides and the bottom of your pen—chicken wire alone will not stop a determined fox, raccoon, or weasel.

Unroll the hardware cloth and cut it to size with tin snips or a utility knife. Staple it to the wooden frame using a staple gun and 1/2-inch staples, overlapping seams by at least 2 inches. Fold the staples over the wire so they don't work loose. For the bottom, either staple hardware cloth directly to the underside of the frame (so it lies flat on the ground), or bury it 6 inches deep and bend it outward in an L-shape to stop digging predators from tunneling underneath.

Check for sharp edges and fold them back or cover them with duct tape so you don't cut yourself or the chickens. A single tear or gap is an invitation to a predator, so inspect the pen regularly and patch any damage when ready.

Add a roof or shade cloth to protect against hawks and weather

An open-top pen is lighter and cheaper to build, but it leaves birds exposed to hawks and heavy rain. A covered top gives you peace of mind and keeps birds dry during storms. You can use hardware cloth on top (which lets light and air through), clear plastic sheeting (which creates a greenhouse effect on hot days), or corrugated roofing panels (which are durable but heavier).

If you use a solid roof, leave one or two sides open or add vents so air circulates and birds don't overheat. In hot climates, shade cloth (a woven fabric that blocks 30 to 50 percent of sunlight) is better than a solid roof because it cools the pen without trapping heat. Attach shade cloth to the frame with clips or zip ties so you can remove it in winter.

For a mobile pen, a lightweight roof made from PVC pipe and clear plastic is easier to move than a heavy wooden frame. For a fixed pen, a permanent roof made from corrugated panels or shingles will last longer and look neater.

may support proper ventilation and drainage so birds stay healthy

Chickens generate moisture and ammonia from their droppings, and a poorly ventilated pen becomes a breeding ground for respiratory disease. Leave gaps or vents on at least two sides of the pen so air flows through. If you add a roof, make sure it doesn't seal the sides completely—birds need cross-ventilation even on rainy days.

Drainage is equally important. If your pen sits in a low spot or on clay soil, water pools underneath and creates mud and disease. Either build the pen on slightly higher ground, or dig a shallow trench around the perimeter to divert water away. For a mobile pen, move it to a new spot every few days so the ground doesn't become waterlogged.

In winter, ventilation becomes a balancing act: you need airflow to prevent moisture buildup, but you also need to block wind and drafts. A covered pen with open sides (not fully enclosed) usually works best. Never seal a pen completely, even in cold weather.

Add features for comfort and safety

Once the basic structure is done, consider adding a door so you can enter the pen to collect eggs, refill water, or catch a bird. A hinged door on one side is easier to use than climbing over the frame. Make sure the door closes securely and latches so it can't blow open or be pushed open by a predator.

Add a ramp or step if the pen sits more than a foot off the ground, so chickens can enter and exit without jumping. Place feeders and waterers inside the pen, but keep them away from corners where predators can hide. In hot weather, provide shade by planting a shrub inside the pen or hanging shade cloth over part of the roof.

For a mobile pen, add wheels or handles so you can move it without lifting the entire structure. A pen with four wheels and a handle can be rolled across grass in seconds, making daily moves much easier. Make sure the wheels lock so the pen doesn't roll away when birds are inside.

Frequently Asked Questions

How big should a chicken pen be?

Plan for at least 3 to 4 square feet per bird inside the pen. A pen for four chickens should be at least 12 to 16 square feet. Larger is always better—more space means less disease, less fighting, and happier birds. A 4-by-8-foot pen works well for a small backyard flock.

Can I use chicken wire instead of hardware cloth?

Chicken wire is not strong enough to stop predators. Raccoons, foxes, and weasels can tear through it or push it aside. Use hardware cloth (1/2-inch mesh) on all sides and the bottom. Chicken wire can be used as a second layer for extra protection, but never as the only barrier.

Do I need to bury the bottom of the pen?

If you live in an area with digging predators (raccoons, foxes, groundhogs), yes. Either staple hardware cloth to the underside of the frame so it lies flat on the ground, or bury it 6 inches deep and bend it outward in an L-shape. This stops predators from tunneling underneath.

How often do I need to move a mobile pen?

Move it every one to three days, depending on flock size and grass growth. A pen with four birds on thick grass can stay in one spot for three days. A pen with eight birds on thin grass should move every day. Moving more often gives birds fresher forage and prevents parasite buildup.

What should I do if a predator damages the pen?

Inspect the pen daily for tears, gaps, or loose staples. Patch any damage when ready with hardware cloth and staples. If a predator has gotten inside, move the surviving birds to a find location and rebuild the damaged section before returning them to the pen.