We've been thinking along the same lines, and buying up as many sheds as we can. It's not very technical, but we can't afford a massive wide span which would cover all the sheep, but allow plenty of air to circulate, so we'll just have to compromise. We're also building an extension to our ancient steading for extra lambing space, as we had to keep them in longer than usual after lambing last year, and got very short of space. This resulted in smaller pens and a very fuggy atmosphere, and at times, chaos! We got away with it last year, our only losses being 2 lambs who died from the cold and wet after they eventually went out, but you can't go on pushing your luck. We do need to get on with the extension, as our main lambing is due to start at the end of the month, and we still haven't put the Southdowns out permanently.