I'm sure there are some commercial turkey farmers over there, with those monster enclosures with the half walls. The ones I've seen have big tarps or heavy plastic sheeting that can be rolled up like an awning for warm weather, or lowered to keep the cold out. I'm sure they'd be glad to show you how they've done theirs; might give you an idea or two.
Or, you could design the runs to accommodate what amounts to old-fashioned storm windows that hook to the top of the window frame so you can remove them or install them, depending on the season.
Ours are small versions of the commercial ones made by Farmtek. They use heavy duty steel framework on 4' centers and a heavy grade poly tarp-like cover. Our older coop is now 9 years old and the cover is just starting to show wear.
Ours are 14 x 24 and we used 4' welded wire fencing attached directly to the frame poles. Ours also has fabric end walls, one zippered and one solid with a door frame inserted. The sides roll up and down and can be opened like canopies as well.