ours are at the plot, granny..we couldn't have them at home, specially with our staffie ;D
plus, all our garden is flags etc, no grass..if your were like ours, they would decimate anything green ;D
ours aren't in the open, the shed is 9x5 and the run is 44x22..plus we are going to extend it by another 12' so they have lots of room to play.
also, our council probably wouldn't agree to us having hens and some of our neighbours would object, I think :-\
good luck whatever you decide, hens are great ;D