Thanks for those couple of replies. I've been reading some of the other posts and, really, if you can't find the answer here then you'll probably not find it anywhere.
Now then, as for the run and hen houses. We built a run first of about 12ft x 6 ft and slopes down from 7ft at the front to about 5ft at the back. It's coverd in wire mesh on the outside with about 1t jutting out under the ground. We aslo bought one of the "3 Large bird" Chinese coop and run. Ha! 3 small chicks more like. The good thing though was that I then had the plans and construction method to build our own which is about 6ft by 3ft. That one sits inside our own run and the smaller one is fixed on the outside with acess to the main area. We don't let them use that. We'll use that for any problem birds we might get or as a hospital wing. We then run an electic fence ( 2 wires at Fox nose height) all the way around it to keep Mr. Fox out.
What we will be doing is extending on the end of the run once we've got our onions lifted. The whole allotment is fenced in to a height of 4ft but we'll extend this upward with netting (I think that both our hens seem to have been watching The Great Escape or Chicken Run) and then cover the whole with netting. We've got a few fruit trees in this allotment and the girls love scratching around in it. We only let them into this bit when we're up there with them, which is why we want to extend the run, put some electric mesh around it and let them free range as much as possible. By the time we're finished they'll have an area of about 5M x 5M, without the orchard part, so they should have enough room to run about in.
I'll also take on board the bit about the pop hole closure as well and try that.
Thanks troops.
Sid