Coops & runs

Chicken run size guide (UK): how much space do hens need?

Run size isn’t a detail — it’s the difference between calm hens and constant problems. This guide helps you size realistically for UK gardens and UK weather.

Brutal truth: most “chicken problems” are just density problems — too many birds in too little space.
Less bullying Less mud Cleaner eggs Easier winters

The honest sizing rule

The more hours your hens spend confined to the run, the more space they need. UK winters (and occasional housing orders) can turn your “free-range plan” into a run-only reality.

Plan for winter: assume you’ll have periods where the run is their whole world.

“Minimum” vs “actually works”

There are welfare minimums. And there’s what produces calm birds, clean eggs, and a garden you can still use.

  • minimums often lead to mud + boredom
  • more space reduces pecking and stress
  • bigger runs stay drier and smell less

The “mud maths” nobody does

If 4 hens are in a small run, every square metre gets walked, scratched, and pooped on constantly. Grass will not survive.

Your two levers are:

  • more space
  • better surfaces + roof/drainage (see mud control)

A practical UK starting point

There isn’t one magic number — because the “right” run size depends on how you keep your birds.

Your setup Run size reality What to prioritise
Run most of the time Go generous. Small runs create problems fast. Space + roof + enrichment + dry surface
Hybrid: run base + free-range when home Still size the run for winter / holidays. Security + enough room to prevent pecking
Mostly free-range The run can be smaller, but it must be secure and usable. Fox-proofing + dry ground plan
Hard truth: if you size the run for “best case”, you’ll suffer in the “real case”.
Use the size calculator Build a run

What changes the run size you need

  • Breed size: heavy birds need more personal space.
  • Age: young birds are chaos; space helps.
  • Weather: wet months = more time confined.
  • Layout: long runs with “zones” reduce bullying.
  • Enrichment: perches, pecking blocks, hanging greens, dust bath area.

If you’re in doubt, default to more space. It’s the cheapest “behaviour fix” you’ll ever buy.

Design tips that make a run feel bigger

  • Break line of sight: add screens/branches so bullied hens can escape.
  • Create dry zones: roof at least part of the run.
  • Add vertical interest: platforms and perches reduce crowding.
  • Two feeders/water points: prevents dominant birds gatekeeping food.

Then make it predator-proof: fox-proofing guide.

The “run only” winter plan

If your hens can’t roam, the run has to do three jobs: security, stimulation, and hygiene.

Security

Welded mesh, roof/cover, dig-proof skirt, strong latches.

Run build designs →

Stimulation

Perches, dust bath, hanging greens, safe logs/branches, scatter feed.

Boredom & behaviour →

Hygiene

Dry flooring strategy, drainage, routine scraping.

Mud control →

Next upgrade if you’re struggling: roof a bigger section of the run. It’s the fastest mud reducer.