Making a hoop coop I'd suggest making something about 6-8m long or maybe even 19-12m long and about 2 & 1/2m tall or for a more easy way to enter a height of 3m. Then you could make the platform at the meter and a half mark. And then 4-5m wide would make the hoop coop the perfect size for 100 chickens.
I’m very inspired now!!
