thanks for all of the input

the problem I am having is the chicken pen out the back is waterlogged-not unsurprising given the biblical rain but there are strange things going on with the downpipes and drains (new house to us, previous occupants did some odd things) out the back-plus the guttering on the workshop needs fixing, all of which we will do but atm, I want that pen of chooks somewhere less horrid. I do want to build a permanent pen out there-with hardcore base and gravel surface with 2/3 grass pens running off it. Its obviously not something I can begin quite yet.they will always get grass, but that particular pen will get less than the others which have huge grass pens.
re the Balfour system-that is something to bear in mind for the future although I wasn't sure if the straw yard was on top of a concrete/hardcore base? what I had in mind is similar but I'm not convinced by deep littering and I don't have a need for compost/manure.
the eco bed looks like the easibed which I already use in their houses and nest boxes

it's free draining and might work. We also have a quarry nearby and I could go and pick up a ton of pea gravel easy enough.
next winter, I may even try a bachelor pen off grass and leave all of the girls on grass-would make my life easier. this winter is being invaluable in showing me what is not going to work here