Fencing a field

[Wonkyparsnip]

I've been given a field to keep 20-30 chickens. I need to fence it off as cheaply as possible. Any ideas? Our chickens at the moment are fenced off using wooden posts that we bought and chicken wire.

Also can anyone recommend where to get chicken coops?

Mmm,I have ten ex- bats since November and we have same dilemma here...dh is going to make a coop we have decided but I would also like a very large enclosed area for when I am not around during the day at times.We currently have our lot in a huge greenhouse with a makeshift coop in there made from scaffolding ,wood and lots of blankets draped over at nightime and then they are out and about during the daytime but although they seem very happy with this arrangement it is only temporary.So I am watching this with interest as we too have a field. How would you put a roof on a field though...to protect from foxes I mean?Or would it just be very high fencing ?.Sorry if I am being a bit thick here....I am thinking a coop and a very large enclosure like 20 ft sq maybe